From 9ac6dac154b0545bdd1de0df4969b7448154b2cd Mon Sep 17 00:00:00 2001
From: David Mak <david.18.19.21@gmail.com>
Date: Fri, 13 Mar 2026 19:22:06 +0800
Subject: [PATCH 01/16] wasm: Deprecate `NumIdx` for external use

---
 hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Wasm.scala | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Wasm.scala b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Wasm.scala
index 155e881def..b90797bfcc 100644
--- a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Wasm.scala
+++ b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Wasm.scala
@@ -158,6 +158,9 @@ type HeapType = AbsHeapType | TypeIdx
 sealed abstract class Index extends ToWat
 
 /** A numeric index. */
+@deprecated(
+  "NumIdx is only used for internal bookkeeping and should not be used in WAT generation; Use SymIdx instead.",
+)
 case class NumIdx(val index: Int) extends Index:
   def toWat: Document = doc"${index.toString}"
 

From 89f16fc3c8edc9e4010b6b4ded969c89f9ecac5c Mon Sep 17 00:00:00 2001
From: David Mak <david.18.19.21@gmail.com>
Date: Fri, 13 Mar 2026 19:43:09 +0800
Subject: [PATCH 02/16] wasm: Store struct fields as `Seq` and require `SymIdx`
 for fields

---
 .../scala/hkmc2/codegen/wasm/text/Wasm.scala  | 10 +++++-----
 .../hkmc2/codegen/wasm/text/WatBuilder.scala  | 18 ++++++++---------
 .../shared/src/test/mlscript/wasm/Basics.mls  | 20 +++++++++----------
 .../src/test/mlscript/wasm/Matching.mls       |  8 ++++----
 .../src/test/mlscript/wasm/ScopedLocals.mls   |  6 +++---
 .../src/test/mlscript/wasm/Singletons.mls     |  6 +++---
 6 files changed, 33 insertions(+), 35 deletions(-)

diff --git a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Wasm.scala b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Wasm.scala
index b90797bfcc..cc291d85b7 100644
--- a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Wasm.scala
+++ b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Wasm.scala
@@ -113,23 +113,23 @@ case class FunctionType(sigType: SignatureType) extends ToWat:
     doc"(func${sigType.toWat.surroundUnlessEmpty(doc" ")})"
 
 /** A type representing a struct field. */
-case class Field(ty: Type, mutable: Bool, id: Opt[Str]) extends ToWat:
+case class Field(ty: Type, mutable: Bool, id: SymIdx) extends ToWat:
   def toWat: Document =
-    doc"(field ${id.fold(doc"")(id => doc"$$$id ")}${
+    doc"(field ${id.toWat} ${
         if mutable then doc"(mut ${ty.toWat})" else ty.toWat
       })"
 
 /** A type representing a structure type. */
 case class StructType(
-    fields: Map[DefinitionSymbol[?], NumIdx -> Field],
+    fields: Seq[DefinitionSymbol[?] -> Field],
     parents: Seq[TypeIdx] = Seq.empty,
     isSubtype: Bool = false,
 ) extends ToWat:
 
-  def fieldSeq: Seq[Field] = fields.values.toSeq.sortBy(_._1.index).map(_._2)
+  lazy val fieldsBySym: Map[DefinitionSymbol[?], Field] = fields.toMap
 
   def toWat: Document =
-    doc"(struct${fieldSeq.map(_.toWat).mkDocument(doc" ").surroundUnlessEmpty(doc" ")})"
+    doc"(struct${fields.map(_._2.toWat).mkDocument(doc" ").surroundUnlessEmpty(doc" ")})"
 
 /** A type representing an array type. */
 case class ArrayType(elemType: Type, mutable: Bool) extends ToWat:
diff --git a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala
index 8465d5e6b3..85a13283c2 100644
--- a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala
+++ b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala
@@ -147,16 +147,14 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
   private def createDefnTypes(b: Block)(using Ctx): Unit = b match
     case Define(defn: ClsLikeDefn, rst) =>
       if isSupportedTopLevelClass(defn) then
-        val inheritedFields = baseObjectStruct.fields.toMap
+        val inheritedFields = baseObjectStruct.fields
         val inheritedSize = inheritedFields.size
 
-        val classFields: Map[DefinitionSymbol[?], NumIdx -> Field] = (defn.publicFields.map(_._2) ++ defn.privateFields)
-          .zipWithIndex
-          .map: (f, index) =>
-            f -> (NumIdx(index + inheritedSize) -> Field(RefType.anyref, mutable = true, id = S(f.nme)))
-          .toMap
+        val classFields = (defn.publicFields.map(_._2) ++ defn.privateFields)
+          .map: f =>
+            f -> Field(RefType.anyref, mutable = true, id = SymIdx(f.nme))
 
-        val allFields: Map[DefinitionSymbol[?], NumIdx -> Field] = inheritedFields ++ classFields
+        val allFields = inheritedFields ++ classFields
 
         // Only parent is base Object for now. For general inheritance add other parents.
         ctx.addType(
@@ -495,7 +493,7 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
   )(using Ctx, Raise): FieldIdx =
     val structInfo = ctx.getTypeInfo_!(thisSym)
     val symToField = structInfo.compType match
-      case ty: StructType => ty.fields
+      case ty: StructType => ty.fieldsBySym
       case _ => lastWords(s"Cannot select field from non-struct type: ${structInfo.compType.toWat}")
     val fieldIdx = symToField.get(sym)
       .orElse:
@@ -504,7 +502,7 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
           case trmSym: TermSymbol if trmSym.owner.flatMap(_.asBlkMember).exists(_ == thisSym) =>
             symToField.find((fieldSym, _) => fieldSym.nme == sym.nme).map((_, v) => v)
           case _ => N
-      .map((fieldidx, _) => fieldidx)
+      .map(_.id)
     FieldIdx(
       fieldIdx getOrElse:
         lastWords(
@@ -1489,7 +1487,7 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
       TypeInfo(
         id = S(SymIdx("Object")),
         StructType(
-          Map(tagFieldSym -> (NumIdx(0) -> Field(I32Type, mutable = true, id = S("$tag")))),
+          Seq(tagFieldSym -> Field(I32Type, mutable = true, id = SymIdx("$tag"))),
           isSubtype = true,
         ),
       ),
diff --git a/hkmc2/shared/src/test/mlscript/wasm/Basics.mls b/hkmc2/shared/src/test/mlscript/wasm/Basics.mls
index 5d9f5691aa..b3c1e55e92 100644
--- a/hkmc2/shared/src/test/mlscript/wasm/Basics.mls
+++ b/hkmc2/shared/src/test/mlscript/wasm/Basics.mls
@@ -130,7 +130,7 @@ class Foo(val a)
 //│           (local.get $this))
 //│         (i32.const 1))
 //│       (block
-//│         (struct.set $Foo 1
+//│         (struct.set $Foo $a
 //│           (ref.cast (ref $Foo)
 //│             (local.get $this))
 //│           (local.get $a))
@@ -149,7 +149,7 @@ class Foo(val a)
 //│           (call $Foo
 //│             (ref.i31
 //│               (i32.const 42))))
-//│         (struct.get $Foo 1
+//│         (struct.get $Foo $a
 //│           (ref.cast (ref $Foo)
 //│             (local.get $tmp))))))
 //│   (export "entry" (func $entry))
@@ -184,15 +184,15 @@ class Foo(val x) with
 //│           (local.get $this))
 //│         (i32.const 1))
 //│       (block
-//│         (struct.set $Foo 1
+//│         (struct.set $Foo $x
 //│           (ref.cast (ref $Foo)
 //│             (local.get $this))
 //│           (local.get $x))
 //│         (block
-//│           (struct.set $Foo 2
+//│           (struct.set $Foo $y
 //│             (ref.cast (ref $Foo)
 //│               (local.get $this))
-//│             (struct.get $Foo 1
+//│             (struct.get $Foo $x
 //│               (ref.cast (ref $Foo)
 //│                 (local.get $this))))
 //│           (nop)))
@@ -210,7 +210,7 @@ class Foo(val x) with
 //│           (call $Foo
 //│             (ref.i31
 //│               (i32.const 42))))
-//│         (struct.get $Foo 2
+//│         (struct.get $Foo $y
 //│           (ref.cast (ref $Foo)
 //│             (local.get $tmp))))))
 //│   (export "entry" (func $entry))
@@ -243,16 +243,16 @@ O.y
 //│           (local.get $this))
 //│         (i32.const 1))
 //│       (block
-//│         (struct.set $O 1
+//│         (struct.set $O $x
 //│           (ref.cast (ref $O)
 //│             (local.get $this))
 //│           (ref.i31
 //│             (i32.const 1)))
 //│         (block
-//│           (struct.set $O 2
+//│           (struct.set $O $y
 //│             (ref.cast (ref $O)
 //│               (local.get $this))
-//│             (struct.get $O 1
+//│             (struct.get $O $x
 //│               (ref.cast (ref $O)
 //│                 (local.get $this))))
 //│           (nop)))
@@ -267,7 +267,7 @@ O.y
 //│     (local $O (ref null any))
 //│     (block (result (ref null any))
 //│       (nop)
-//│       (struct.get $O 2
+//│       (struct.get $O $y
 //│         (ref.cast (ref $O)
 //│           (global.get $O$inst)))))
 //│   (export "entry" (func $entry))
diff --git a/hkmc2/shared/src/test/mlscript/wasm/Matching.mls b/hkmc2/shared/src/test/mlscript/wasm/Matching.mls
index 0b9d3acc9e..5d96862b9b 100644
--- a/hkmc2/shared/src/test/mlscript/wasm/Matching.mls
+++ b/hkmc2/shared/src/test/mlscript/wasm/Matching.mls
@@ -59,7 +59,7 @@ if Bar(true) is
 //│           (local.get $this))
 //│         (i32.const 1))
 //│       (block
-//│         (struct.set $Bar 1
+//│         (struct.set $Bar $y
 //│           (ref.cast (ref $Bar)
 //│             (local.get $this))
 //│           (local.get $y))
@@ -78,7 +78,7 @@ if Bar(true) is
 //│           (local.get $this))
 //│         (i32.const 2))
 //│       (block
-//│         (struct.set $Baz 1
+//│         (struct.set $Baz $z
 //│           (ref.cast (ref $Baz)
 //│             (local.get $this))
 //│           (local.get $z))
@@ -126,7 +126,7 @@ if Bar(true) is
 //│                         (local.set $matchRes
 //│                           (block (result (ref null any))
 //│                             (local.set $arg$Bar$0$
-//│                               (struct.get $Bar 1
+//│                               (struct.get $Bar $y
 //│                                 (ref.cast (ref $Bar)
 //│                                   (local.get $scrut))))
 //│                             (block (result (ref null any))
@@ -168,7 +168,7 @@ if Bar(true) is
 //│                         (local.set $matchRes
 //│                           (block (result (ref null any))
 //│                             (local.set $arg$Baz$0$
-//│                               (struct.get $Baz 1
+//│                               (struct.get $Baz $z
 //│                                 (ref.cast (ref $Baz)
 //│                                   (local.get $scrut))))
 //│                             (block (result (ref null any))
diff --git a/hkmc2/shared/src/test/mlscript/wasm/ScopedLocals.mls b/hkmc2/shared/src/test/mlscript/wasm/ScopedLocals.mls
index 775d0a2e3c..5b82a49b94 100644
--- a/hkmc2/shared/src/test/mlscript/wasm/ScopedLocals.mls
+++ b/hkmc2/shared/src/test/mlscript/wasm/ScopedLocals.mls
@@ -181,12 +181,12 @@ class Foo(val a, val b)
 //│           (local.get $this))
 //│         (i32.const 1))
 //│       (block
-//│         (struct.set $Foo 1
+//│         (struct.set $Foo $a
 //│           (ref.cast (ref $Foo)
 //│             (local.get $this))
 //│           (local.get $a))
 //│         (block
-//│           (struct.set $Foo 2
+//│           (struct.set $Foo $b
 //│             (ref.cast (ref $Foo)
 //│               (local.get $this))
 //│             (local.get $b))
@@ -207,7 +207,7 @@ class Foo(val a, val b)
 //│               (i32.const 42))
 //│             (ref.i31
 //│               (i32.const 1))))
-//│         (struct.get $Foo 1
+//│         (struct.get $Foo $a
 //│           (ref.cast (ref $Foo)
 //│             (local.get $tmp))))))
 //│   (export "entry" (func $entry))
diff --git a/hkmc2/shared/src/test/mlscript/wasm/Singletons.mls b/hkmc2/shared/src/test/mlscript/wasm/Singletons.mls
index dc31b18afb..ec60b20877 100644
--- a/hkmc2/shared/src/test/mlscript/wasm/Singletons.mls
+++ b/hkmc2/shared/src/test/mlscript/wasm/Singletons.mls
@@ -31,7 +31,7 @@ Bar.y
 //│           (local.get $this))
 //│         (i32.const 1))
 //│       (block
-//│         (struct.set $Foo 1
+//│         (struct.set $Foo $x
 //│           (ref.cast (ref $Foo)
 //│             (local.get $this))
 //│           (ref.i31
@@ -49,7 +49,7 @@ Bar.y
 //│           (local.get $this))
 //│         (i32.const 2))
 //│       (block
-//│         (struct.set $Bar 1
+//│         (struct.set $Bar $y
 //│           (ref.cast (ref $Bar)
 //│             (local.get $this))
 //│           (ref.i31
@@ -72,7 +72,7 @@ Bar.y
 //│       (nop)
 //│       (block (result (ref null any))
 //│         (nop)
-//│         (struct.get $Bar 1
+//│         (struct.get $Bar $y
 //│           (ref.cast (ref $Bar)
 //│             (global.get $Bar$inst))))))
 //│   (export "entry" (func $entry))

From c19ac6a862290f983fc3e2b75e38337e83cded55 Mon Sep 17 00:00:00 2001
From: David Mak <david.18.19.21@gmail.com>
Date: Fri, 13 Mar 2026 20:00:43 +0800
Subject: [PATCH 03/16] wasm: Store numeric indices as integers

---
 .../scala/hkmc2/codegen/wasm/text/Ctx.scala   | 48 +++++++++----------
 1 file changed, 24 insertions(+), 24 deletions(-)

diff --git a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala
index b94858d368..16ed6def66 100644
--- a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala
+++ b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala
@@ -241,17 +241,17 @@ end Ctx
   */
 class Ctx(
     types: ArrayBuf[TypeInfo],
-    namedTypes: MutMap[BlockMemberSymbol, NumIdx],
+    namedTypes: MutMap[BlockMemberSymbol, Int],
     memoryImports: ArrayBuf[MemoryImport],
     functionImports: ArrayBuf[FuncImport],
     dataSegments: ArrayBuf[DataSegment],
     funcs: ArrayBuf[FuncInfo],
-    funcInfosByIndex: MutMap[NumIdx, FuncInfo],
+    funcInfosByIndex: MutMap[Int, FuncInfo],
     globals: ArrayBuf[GlobalInfo],
-    namedFuncs: MutMap[Symbol, NumIdx],
+    namedFuncs: MutMap[Symbol, Int],
     tags: ArrayBuf[TagInfo],
-    namedGlobals: MutMap[Symbol, NumIdx],
-    var locals: Ls[MutMap[Local, NumIdx]],
+    namedGlobals: MutMap[Symbol, Int],
+    var locals: Ls[MutMap[Local, Int]],
     private var startFunc: Opt[FuncIdx],
 ) extends ToWat:
 
@@ -283,20 +283,20 @@ class Ctx(
 
   /** Adds a type into this context. */
   def addType(sym: Opt[BlockMemberSymbol], typeInfo: TypeInfo): TypeIdx =
-    val numIdx = NumIdx(types.size)
+    val numIdx = types.size
     types += typeInfo
     sym.foreach:
       namedTypes(_) = numIdx
-    TypeIdx(typeInfo.id.getOrElse(numIdx))
+    TypeIdx(typeInfo.id.getOrElse(NumIdx(numIdx)))
 
   /** Returns the [[TypeIdx]] of the given `typeref`, optionally resolving the symbolic index into a numeric index.
     */
   def getType(typeref: TypeIdx | BlockMemberSymbol, resolveSymIdx: Bool = false): Opt[TypeIdx] =
     typeref match
       case TypeIdx(SymIdx(nme)) if resolveSymIdx =>
-        namedTypes.find(_._1.nme == nme).map(t => TypeIdx(t._2))
+        namedTypes.find(_._1.nme == nme).map(t => TypeIdx(NumIdx(t._2)))
       case typeidx: TypeIdx => S(typeidx)
-      case sym: BlockMemberSymbol if resolveSymIdx => namedTypes.get(sym).map(TypeIdx(_))
+      case sym: BlockMemberSymbol if resolveSymIdx => namedTypes.get(sym).map(idx => TypeIdx(NumIdx(idx)))
       case sym: BlockMemberSymbol =>
         getType(sym, resolveSymIdx = true).map: numIdx =>
           getTypeInfo(numIdx).flatMap(_.id).fold(numIdx)(TypeIdx(_))
@@ -310,8 +310,8 @@ class Ctx(
   def getTypeInfo(typeref: TypeIdx | BlockMemberSymbol): Opt[TypeInfo] = typeref match
     case TypeIdx(NumIdx(idx)) => types.unapply(idx.toInt)
     case TypeIdx(SymIdx(nme)) =>
-      namedTypes.find(_._1.nme == nme).flatMap(t => getTypeInfo(TypeIdx(t._2)))
-    case sym: BlockMemberSymbol => namedTypes.get(sym).flatMap(idx => getTypeInfo(TypeIdx(idx)))
+      namedTypes.find(_._1.nme == nme).flatMap(t => getTypeInfo(TypeIdx(NumIdx(t._2))))
+    case sym: BlockMemberSymbol => namedTypes.get(sym).flatMap(idx => getTypeInfo(TypeIdx(NumIdx(idx))))
 
   /** Same as [[getTypeInfo]] but throws an exception when the `typeref` is not found. */
   def getTypeInfo_!(typeref: TypeIdx | BlockMemberSymbol): TypeInfo =
@@ -320,23 +320,23 @@ class Ctx(
 
   /** Adds a function into this context. */
   def addFunc(sym: Opt[Symbol], funcInfo: FuncInfo): FuncIdx =
-    val numIdx = NumIdx(functionImports.size + funcs.size)
+    val numIdx = functionImports.size + funcs.size
     funcs += funcInfo
     funcInfosByIndex(numIdx) = funcInfo
     sym.foreach:
       namedFuncs(_) = numIdx
-    FuncIdx(funcInfo.id.getOrElse(numIdx))
+    FuncIdx(funcInfo.id.getOrElse(NumIdx(numIdx)))
 
   /** Adds a function import into this context.
     *
     * Returns the function index in the global function index space.
     */
   def addFunctionImport(sym: Opt[Symbol], funcImport: FuncImport): FuncIdx =
-    val numIdx = NumIdx(functionImports.size + funcs.size)
+    val numIdx = functionImports.size + funcs.size
     functionImports += funcImport
     sym.foreach:
       namedFuncs(_) = numIdx
-    FuncIdx(funcImport.id.getOrElse(numIdx))
+    FuncIdx(funcImport.id.getOrElse(NumIdx(numIdx)))
 
   /** Returns the cached function import for (`module`, `name`), creating it with `createImport` if needed.
     */
@@ -379,9 +379,9 @@ class Ctx(
     */
   def getFunc(funcref: FuncIdx | Symbol, resolveSymIdx: Bool = false): Opt[FuncIdx] = funcref match
     case FuncIdx(SymIdx(nme)) if resolveSymIdx =>
-      namedFuncs.find(_._1.nme == nme).map(f => FuncIdx(f._2))
+      namedFuncs.find(_._1.nme == nme).map(f => FuncIdx(NumIdx(f._2)))
     case funcidx: FuncIdx => S(funcidx)
-    case sym: Symbol if resolveSymIdx => namedFuncs.get(sym).map(FuncIdx(_))
+    case sym: Symbol if resolveSymIdx => namedFuncs.get(sym).map(idx => FuncIdx(NumIdx(idx)))
     case sym: Symbol =>
       getFunc(sym, resolveSymIdx = true).map: numIdx =>
         getFuncInfo(numIdx).flatMap(_.id).fold(numIdx)(FuncIdx(_))
@@ -393,8 +393,8 @@ class Ctx(
 
   /** Returns the [[FuncInfo]] instance associated with the given `funcref`. */
   def getFuncInfo(funcref: FuncIdx | Symbol): Opt[FuncInfo] = funcref match
-    case FuncIdx(numIdx @ NumIdx(idx)) =>
-      funcInfosByIndex.get(numIdx).orElse:
+    case FuncIdx(NumIdx(idx)) =>
+      funcInfosByIndex.get(idx).orElse:
         val localIdx = idx.toInt - functionImports.size
         if localIdx < 0 then N else funcs.unapply(localIdx)
     case funcref => getFunc(funcref, resolveSymIdx = true).flatMap(getFuncInfo(_))
@@ -412,9 +412,9 @@ class Ctx(
 
   /** Adds a new local variable into the top-most variable scope. */
   def addLocal(sym: Local): LocalIdx =
-    val numIdx = NumIdx(locals.head.size)
+    val numIdx = locals.head.size
     locals.head(sym) = numIdx
-    LocalIdx(numIdx)
+    LocalIdx(NumIdx(numIdx))
 
   /** Adds a [[Seq]] of local variables into the top-most variable scope. */
   def addLocals(syms: Seq[Local]): Seq[LocalIdx] =
@@ -425,7 +425,7 @@ class Ctx(
 
   /** Adds a new variable into the global variable scope. */
   def addGlobal(sym: Symbol, globalInfo: GlobalInfo): GlobalIdx =
-    val numIdx = NumIdx(globals.size)
+    val numIdx = globals.size
     globals += globalInfo
     namedGlobals(sym) = numIdx
     GlobalIdx(globalInfo.id)
@@ -472,8 +472,8 @@ class Ctx(
   /** Converts a [[Map]] of symbols and their respective numeric identifiers into a [[Seq]] of symbols sorted by its
     * numeric index.
     */
-  private def wasmLocalsToSeq(scope: Map[Symbol, NumIdx]): Seq[Local] =
-    scope.toSeq.sortBy(_._2.index).map(_._1)
+  private def wasmLocalsToSeq(scope: Map[Symbol, Int]): Seq[Local] =
+    scope.toSeq.sortBy(_._2).map(_._1)
 
   /** Returns a tuple containing the variables in the current `global` and `local` scopes respectively.
     */

From 87706c2dc578d588db148c7a42994f4429ea3a87 Mon Sep 17 00:00:00 2001
From: David Mak <david.18.19.21@gmail.com>
Date: Fri, 13 Mar 2026 20:02:53 +0800
Subject: [PATCH 04/16] wasm: Return `SymIdx` from `addLocal`

---
 hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala
index 16ed6def66..10926ae89b 100644
--- a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala
+++ b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala
@@ -414,7 +414,7 @@ class Ctx(
   def addLocal(sym: Local): LocalIdx =
     val numIdx = locals.head.size
     locals.head(sym) = numIdx
-    LocalIdx(NumIdx(numIdx))
+    LocalIdx(SymIdx(sym.nme))
 
   /** Adds a [[Seq]] of local variables into the top-most variable scope. */
   def addLocals(syms: Seq[Local]): Seq[LocalIdx] =

From 090adb75b2c8fcc4c2da3958dfbe3c3eacc5f0bf Mon Sep 17 00:00:00 2001
From: David Mak <david.18.19.21@gmail.com>
Date: Sat, 14 Mar 2026 00:22:06 +0800
Subject: [PATCH 05/16] wasm: Make symbolic index for types mandatory

- User-defined types will use the type name as its symbolic index ID
- Synthetic types will use a generated name based on its context as its
  symbolic index ID
---
 .../scala/hkmc2/codegen/wasm/text/Ctx.scala   | 54 +++++++++++--------
 .../hkmc2/codegen/wasm/text/WatBuilder.scala  | 45 +++++++++-------
 .../shared/src/test/mlscript/wasm/Basics.mls  | 36 ++++++-------
 .../test/mlscript/wasm/BuiltinOperators.mls   | 24 ++++-----
 .../src/test/mlscript/wasm/ControlFlow.mls    | 22 ++++----
 .../src/test/mlscript/wasm/Exceptions.mls     |  8 +--
 .../src/test/mlscript/wasm/Matching.mls       | 14 ++---
 .../src/test/mlscript/wasm/ScopedLocals.mls   | 30 +++++------
 .../src/test/mlscript/wasm/SingletonUnit.mls  |  8 +--
 .../src/test/mlscript/wasm/Singletons.mls     |  4 +-
 .../shared/src/test/mlscript/wasm/Strings.mls |  8 +--
 .../shared/src/test/mlscript/wasm/Tuples.mls  |  4 +-
 12 files changed, 137 insertions(+), 120 deletions(-)

diff --git a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala
index 10926ae89b..df9280ab60 100644
--- a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala
+++ b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala
@@ -8,7 +8,7 @@ import hkmc2.utils.*
 
 import document.*
 import document.Document
-import semantics.*
+import semantics.*, Elaborator.State
 import text.Param as WasmParam
 import Instructions.*
 
@@ -122,28 +122,30 @@ end GlobalInfo
   * @param compType
   *   The composite type this type definition represents.
   */
-class TypeInfo(val id: Opt[SymIdx], val compType: CompType) extends ToWat:
+class TypeInfo(val id: SymIdx, val compType: CompType) extends ToWat:
 
   /** @param sym
     *   The source [[BlockMemberSymbol]] which this type is generated from.
     * @param compType
     *   The composite type this type definition represents.
     */
-  def this(sym: BlockMemberSymbol, compType: CompType) = this(
-    sym.optionIf(_.nameIsMeaningful).map(sym => SymIdx(sym.nme)),
+  def this(sym: BlockMemberSymbol, compType: CompType)(using Raise, Scope) = this(
+    SymIdx(sym.optionIf(_.nameIsMeaningful).fold(summon[Scope].allocateName(sym))(_.nme)),
     compType,
   )
 
-  private def idDoc: Document = id.fold(doc"")(_.toWat)
+  @deprecated("Consider providing a symbolic identifier by using `Scope.allocateName` with a `TempSymbol`.")
+  def this(id: Opt[SymIdx], compType: CompType)(using Raise, Scope, State) =
+    this(id.getOrElse(SymIdx(summon[Scope].allocateName(TempSymbol(N, "")))), compType)
 
   def toWat: Document = compType match
     case struct: StructType if struct.isSubtype =>
       val parentsDoc = struct.parents.optionIf(_.nonEmpty).fold(doc""): parents =>
         parents.map(_.toWat).mkDocument(doc" ")
       val structDoc = struct.copy(isSubtype = false).toWat
-      doc"(type${idDoc.surroundUnlessEmpty(doc" ")} (sub${parentsDoc.surroundUnlessEmpty(doc" ")} ${structDoc}))"
+      doc"(type ${id.toWat} (sub${parentsDoc.surroundUnlessEmpty(doc" ")} ${structDoc}))"
     case _ =>
-      doc"(type${idDoc.surroundUnlessEmpty(doc" ")} ${compType.toWat})"
+      doc"(type ${id.toWat} ${compType.toWat})"
 end TypeInfo
 
 /** A WebAssembly exception tag declaration.
@@ -287,31 +289,41 @@ class Ctx(
     types += typeInfo
     sym.foreach:
       namedTypes(_) = numIdx
-    TypeIdx(typeInfo.id.getOrElse(NumIdx(numIdx)))
+    TypeIdx(typeInfo.id)
+
+  @deprecated("Use the overload without `resolveSymIdx` instead.")
+  def getType(typeref: TypeIdx | BlockMemberSymbol, resolveSymIdx: Bool): Opt[TypeIdx] =
+    if resolveSymIdx then
+      typeref match
+        case TypeIdx(SymIdx(nme)) =>
+          namedTypes.find(_._1.nme == nme).map(t => TypeIdx(NumIdx(t._2)))
+        case typeidx: TypeIdx => S(typeidx)
+        case sym: BlockMemberSymbol => namedTypes.get(sym).map(idx => TypeIdx(NumIdx(idx)))
+    else getType(typeref)
 
   /** Returns the [[TypeIdx]] of the given `typeref`, optionally resolving the symbolic index into a numeric index.
     */
-  def getType(typeref: TypeIdx | BlockMemberSymbol, resolveSymIdx: Bool = false): Opt[TypeIdx] =
-    typeref match
-      case TypeIdx(SymIdx(nme)) if resolveSymIdx =>
-        namedTypes.find(_._1.nme == nme).map(t => TypeIdx(NumIdx(t._2)))
-      case typeidx: TypeIdx => S(typeidx)
-      case sym: BlockMemberSymbol if resolveSymIdx => namedTypes.get(sym).map(idx => TypeIdx(NumIdx(idx)))
-      case sym: BlockMemberSymbol =>
-        getType(sym, resolveSymIdx = true).map: numIdx =>
-          getTypeInfo(numIdx).flatMap(_.id).fold(numIdx)(TypeIdx(_))
+  def getType(typeref: TypeIdx | BlockMemberSymbol): Opt[TypeIdx] = typeref match
+    case typeidx: TypeIdx => S(typeidx)
+    case sym: BlockMemberSymbol => getTypeInfo(typeref).map(ti => TypeIdx(ti.id))
 
-  /** Same as [[getType]] but throws an exception when the `typeref` is not found. */
-  def getType_!(typeref: TypeIdx | BlockMemberSymbol, resolveSymIdx: Bool = false): TypeIdx =
+  @deprecated("Use the overload without `resolveSymIdx` instead.")
+  def getType_!(typeref: TypeIdx | BlockMemberSymbol, resolveSymIdx: Bool): TypeIdx =
     getType(typeref, resolveSymIdx).getOrElse:
       lastWords(s"Missing type definition for ${typeref.prettyString}")
 
+  /** Same as [[getType]] but throws an exception when the `typeref` is not found. */
+  def getType_!(typeref: TypeIdx | BlockMemberSymbol): TypeIdx =
+    getType(typeref).getOrElse:
+      lastWords(s"Missing type definition for ${typeref.prettyString}")
+
   /** Returns the [[TypeInfo]] instance associated with the given `typeref`. */
   def getTypeInfo(typeref: TypeIdx | BlockMemberSymbol): Opt[TypeInfo] = typeref match
     case TypeIdx(NumIdx(idx)) => types.unapply(idx.toInt)
     case TypeIdx(SymIdx(nme)) =>
-      namedTypes.find(_._1.nme == nme).flatMap(t => getTypeInfo(TypeIdx(NumIdx(t._2))))
-    case sym: BlockMemberSymbol => namedTypes.get(sym).flatMap(idx => getTypeInfo(TypeIdx(NumIdx(idx))))
+      // TODO(Derppening): Consider adding a `Map[SymIdx, TypeInfo]` for faster lookup
+      types.find(_.id.id == nme)
+    case sym: BlockMemberSymbol => namedTypes.get(sym).map(idx => types(idx))
 
   /** Same as [[getTypeInfo]] but throws an exception when the `typeref` is not found. */
   def getTypeInfo_!(typeref: TypeIdx | BlockMemberSymbol): TypeInfo =
diff --git a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala
index 85a13283c2..4142324682 100644
--- a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala
+++ b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala
@@ -144,7 +144,7 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
   end registerSingletonInit
 
   /** Recursively declares supported top-level class types (needed for nested function codegen). */
-  private def createDefnTypes(b: Block)(using Ctx): Unit = b match
+  private def createDefnTypes(b: Block)(using Ctx, Raise, Scope): Unit = b match
     case Define(defn: ClsLikeDefn, rst) =>
       if isSupportedTopLevelClass(defn) then
         val inheritedFields = baseObjectStruct.fields
@@ -160,7 +160,7 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
         ctx.addType(
           sym = S(defn.sym),
           typeInfo = TypeInfo(
-            id = S(SymIdx(defn.sym.nme)),
+            sym = defn.sym,
             compType = StructType(fields = allFields, parents = Seq(baseObjectTypeIdx), isSubtype = true),
           ),
         )
@@ -192,7 +192,8 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
     case _: BlockTail => ()
 
   /** Gets (and caches) the exception tag used for MLX `throw`. */
-  private def exnTagIdx(using Ctx): TagIdx =
+  private def exnTagIdx(using Ctx, Raise, Scope): TagIdx =
+    val symNme = scope.allocateName(TempSymbol(N, "mlx_exn"))
     ctx.getOrCreateWasmIntrinsicTag(
       "mlx_exn",
       ctx.addTag(TagInfo(
@@ -200,7 +201,7 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
         typeIdx = ctx.addType(
           sym = N,
           TypeInfo(
-            id = N,
+            id = SymIdx(symNme),
             FunctionType(params = Seq(WasmParam(N, RefType.anyref)), results = Seq.empty),
           ),
         ),
@@ -229,7 +230,7 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
 
   /** Ensures imports required for string materialization exist and returns the constructor function.
     */
-  private def getOrLoadStrCtorFunction(using Ctx): FuncIdx =
+  private def getOrLoadStrCtorFunction(using Ctx, Raise, Scope): FuncIdx =
     val minBytes = nextStringDataOffset
     val pageSize = ExternIntrinsics.WasmPageSizeBytes
     val minPages =
@@ -244,10 +245,11 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
       module = ExternIntrinsics.SystemModule,
       name = ExternIntrinsics.StringFromUtf16ImportName,
     ):
+      val importTyNme = scope.allocateName(TempSymbol(N, ExternIntrinsics.StringFromUtf16ImportName))
       val importTy = ctx.addType(
         sym = N,
         TypeInfo(
-          id = N,
+          id = SymIdx(importTyNme),
           FunctionType(
             params = Seq(WasmParam(N, RefType.anyref), WasmParam(N, RefType.anyref)),
             results = Seq(Result(RefType.anyref)),
@@ -264,7 +266,7 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
 
   /** Gets (and caches) the Wasm GC array type used for tuples (`mut` selects mutability).
     */
-  private def tupleArrayType(mut: Bool)(using Ctx): TypeIdx =
+  private def tupleArrayType(mut: Bool)(using Ctx, Raise, Scope): TypeIdx =
     ctx.getOrCreateWasmIntrinsicType(WasmIntrinsicType.TupleArray(mutable = mut)):
       val suffix = if mut then "Mut" else ""
       val sym = BlockMemberSymbol(s"TupleArray$suffix", Nil)
@@ -736,12 +738,12 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
 
   /** Gets (or creates) the intrinsic function implementing the wasm operator `name`.
     */
-  private def getIntrinsic(name: Str)(using Ctx, Scope): FuncIdx =
+  private def getIntrinsic(name: Str)(using Ctx, Raise, Scope): FuncIdx =
     ctx.getOrCreateWasmIntrinsic(name, createIntrinsic(name))
 
   /** Creates the intrinsic definition for `name`.
     */
-  private def createIntrinsic(name: Str)(using Ctx, Scope): FuncIdx =
+  private def createIntrinsic(name: Str)(using Ctx, Raise, Scope): FuncIdx =
     if binaryOps.contains(name) then createBinaryInt31Func(name, binaryOps(name))
     else if unaryOps.contains(name) then createUnaryInt31Func(name, unaryOps(name))
     else lastWords(s"Unsupported wasm intrinsic '$name'")
@@ -751,7 +753,7 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
   private def createBinaryInt31Func(
       name: Str,
       op: (Expr, Expr) => Expr,
-  )(using Ctx, Scope): FuncIdx =
+  )(using Ctx, Raise, Scope): FuncIdx =
     val params = mkIntrinsicParams(name, Seq("lhs", "rhs"))
     val lhsName = params.head._2
     val rhsName = params(1)._2
@@ -760,7 +762,7 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
 
   /** Creates a unary Int31 intrinsic with a single parameter and body built from `op`.
     */
-  private def createUnaryInt31Func(name: Str, op: Expr => Expr)(using Ctx, Scope): FuncIdx =
+  private def createUnaryInt31Func(name: Str, op: Expr => Expr)(using Ctx, Raise, Scope): FuncIdx =
     val params = mkIntrinsicParams(name, Seq("arg"))
     val argName = params.head._2
     val body = unaryInt31Body(argName, op)
@@ -772,11 +774,11 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
       name: Str,
       params: Seq[(TempSymbol, Str)],
       body: Expr,
-  )(using Ctx): FuncIdx =
+  )(using Ctx, Raise, Scope): FuncIdx =
     val funcTy = ctx.addType(
       sym = N,
       TypeInfo(
-        id = N,
+        id = SymIdx(scope.allocateName(TempSymbol(N, name))),
         FunctionType(
           params = params.map((_, nme) => WasmParam(S(nme), RefType.anyref)),
           results = Seq(Result(RefType.anyref)),
@@ -1014,7 +1016,7 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
                       val funcTy = ctx.addType(
                         sym = N,
                         TypeInfo(
-                          id = N,
+                          id = SymIdx(scope.allocateName(TempSymbol(N, sym.nme))),
                           FunctionType(
                             params = params.map(_._1),
                             results = Seq.fill(bodyWat.resultTypes.length)(Result(RefType.anyref)),
@@ -1116,12 +1118,12 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
                       break(errUnimplExpr("newCtorAuxParams.nonEmpty"))
 
                     val funcTyId =
-                      if isSingletonObj then S(SymIdx(s"${clsLikeDefn.sym.nme}_ctor"))
-                      else N
+                      if isSingletonObj then s"${clsLikeDefn.sym.nme}_ctor"
+                      else scope.allocateName(TempSymbol(N, s"${clsLikeDefn.sym.nme}_ctor"))
                     val funcTy = ctx.addType(
                       sym = N,
                       TypeInfo(
-                        id = funcTyId,
+                        id = SymIdx(funcTyId),
                         FunctionType(
                           params = ctorParams.map(p => WasmParam(S(p._2), RefType.anyref)),
                           results = Seq(Result(RefType.anyref)),
@@ -1485,7 +1487,7 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
     ctx.addType(
       sym = S(baseObjectSym),
       TypeInfo(
-        id = S(SymIdx("Object")),
+        id = SymIdx("Object"),
         StructType(
           Seq(tagFieldSym -> Field(I32Type, mutable = true, id = SymIdx("$tag"))),
           isSubtype = true,
@@ -1509,7 +1511,10 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
 
     val entryFnTy = ctx.addType(
       sym = N,
-      TypeInfo(id = N, FunctionType(params = Seq.empty, results = Seq(Result(RefType.anyref)))),
+      TypeInfo(
+        id = SymIdx(scope.allocateName(TempSymbol(N, entryNme))),
+        FunctionType(params = Seq.empty, results = Seq(Result(RefType.anyref))),
+      ),
     )
     val entryFnInfo = FuncInfo(
       id = S(SymIdx(entryNme)),
@@ -1532,7 +1537,7 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
       val initTy = ctx.addType(
         sym = N,
         TypeInfo(
-          id = S(SymIdx("start")),
+          id = SymIdx(scope.allocateName(TempSymbol(N, "start"))),
           FunctionType(params = Seq.empty, results = Seq.empty),
         ),
       )
diff --git a/hkmc2/shared/src/test/mlscript/wasm/Basics.mls b/hkmc2/shared/src/test/mlscript/wasm/Basics.mls
index b3c1e55e92..c449e8a9ac 100644
--- a/hkmc2/shared/src/test/mlscript/wasm/Basics.mls
+++ b/hkmc2/shared/src/test/mlscript/wasm/Basics.mls
@@ -49,16 +49,16 @@ foo() + foo()
 //│ Wat:
 //│ (module
 //│   (type $Object (sub (struct (field $$tag (mut i32)))))
-//│   (type (func (result (ref null any))))
-//│   (type (func (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))))
-//│   (type (func (result (ref null any))))
-//│   (func $foo (type 1) (result (ref null any))
+//│   (type $foo1 (func (result (ref null any))))
+//│   (type $plus_impl (func (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))))
+//│   (type $entry1 (func (result (ref null any))))
+//│   (func $foo (type $foo1) (result (ref null any))
 //│     (return
 //│       (ref.i31
 //│         (i32.const 42))))
 //│   (export "foo" (func $foo))
 //│   (elem declare func $foo)
-//│   (func  (type 2) (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))
+//│   (func  (type $plus_impl) (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))
 //│     (if (result (ref null any))
 //│       (i32.and
 //│         (ref.test (ref null i31)
@@ -76,7 +76,7 @@ foo() + foo()
 //│                 (local.get $rhs))))))
 //│       (else
 //│         (unreachable))))
-//│   (func $entry (type 3) (result (ref null any))
+//│   (func $entry (type $entry1) (result (ref null any))
 //│     (local $foo (ref null any))
 //│     (local $tmp (ref null any))
 //│     (local $tmp1 (ref null any))
@@ -84,11 +84,11 @@ foo() + foo()
 //│       (nop)
 //│       (block (result (ref null any))
 //│         (local.set $tmp
-//│           (call_ref 1
+//│           (call_ref $foo1
 //│             (ref.func $foo)))
 //│         (block (result (ref null any))
 //│           (local.set $tmp1
-//│             (call_ref 1
+//│             (call_ref $foo1
 //│               (ref.func $foo)))
 //│           (call 1
 //│             (local.get $tmp)
@@ -118,9 +118,9 @@ class Foo(val a)
 //│ (module
 //│   (type $Object (sub (struct (field $$tag (mut i32)))))
 //│   (type $Foo (sub $Object (struct (field $$tag (mut i32)) (field $a (mut (ref null any))))))
-//│   (type (func (param $a (ref null any)) (result (ref null any))))
-//│   (type (func (result (ref null any))))
-//│   (func $Foo (type 2) (param $a (ref null any)) (result (ref null any))
+//│   (type $Foo_ctor (func (param $a (ref null any)) (result (ref null any))))
+//│   (type $entry1 (func (result (ref null any))))
+//│   (func $Foo (type $Foo_ctor) (param $a (ref null any)) (result (ref null any))
 //│     (local $this (ref null any))
 //│     (block (result (ref null any))
 //│       (local.set $this
@@ -139,7 +139,7 @@ class Foo(val a)
 //│         (local.get $this))))
 //│   (export "Foo" (func $Foo))
 //│   (elem declare func $Foo)
-//│   (func $entry (type 3) (result (ref null any))
+//│   (func $entry (type $entry1) (result (ref null any))
 //│     (local $Foo (ref null any))
 //│     (local $tmp (ref null any))
 //│     (block (result (ref null any))
@@ -172,9 +172,9 @@ class Foo(val x) with
 //│ (module
 //│   (type $Object (sub (struct (field $$tag (mut i32)))))
 //│   (type $Foo (sub $Object (struct (field $$tag (mut i32)) (field $x (mut (ref null any))) (field $y (mut (ref null any))))))
-//│   (type (func (param $x (ref null any)) (result (ref null any))))
-//│   (type (func (result (ref null any))))
-//│   (func $Foo (type 2) (param $x (ref null any)) (result (ref null any))
+//│   (type $Foo_ctor (func (param $x (ref null any)) (result (ref null any))))
+//│   (type $entry1 (func (result (ref null any))))
+//│   (func $Foo (type $Foo_ctor) (param $x (ref null any)) (result (ref null any))
 //│     (local $this (ref null any))
 //│     (block (result (ref null any))
 //│       (local.set $this
@@ -200,7 +200,7 @@ class Foo(val x) with
 //│         (local.get $this))))
 //│   (export "Foo" (func $Foo))
 //│   (elem declare func $Foo)
-//│   (func $entry (type 3) (result (ref null any))
+//│   (func $entry (type $entry1) (result (ref null any))
 //│     (local $Foo (ref null any))
 //│     (local $tmp (ref null any))
 //│     (block (result (ref null any))
@@ -229,7 +229,7 @@ O.y
 //│   (type $Object (sub (struct (field $$tag (mut i32)))))
 //│   (type $O (sub $Object (struct (field $$tag (mut i32)) (field $x (mut (ref null any))) (field $y (mut (ref null any))))))
 //│   (type $O_ctor (func (result (ref null any))))
-//│   (type (func (result (ref null any))))
+//│   (type $entry1 (func (result (ref null any))))
 //│   (type $start (func))
 //│   (global $O$inst (mut (ref null $O)) (ref.null $O))
 //│   (start 1)
@@ -263,7 +263,7 @@ O.y
 //│       (global.set $O$inst
 //│         (ref.cast (ref null $O)
 //│           (call 0)))))
-//│   (func $entry (type 3) (result (ref null any))
+//│   (func $entry (type $entry1) (result (ref null any))
 //│     (local $O (ref null any))
 //│     (block (result (ref null any))
 //│       (nop)
diff --git a/hkmc2/shared/src/test/mlscript/wasm/BuiltinOperators.mls b/hkmc2/shared/src/test/mlscript/wasm/BuiltinOperators.mls
index 0f50f09946..21e9c29e75 100644
--- a/hkmc2/shared/src/test/mlscript/wasm/BuiltinOperators.mls
+++ b/hkmc2/shared/src/test/mlscript/wasm/BuiltinOperators.mls
@@ -7,9 +7,9 @@
 //│ Wat:
 //│ (module
 //│   (type $Object (sub (struct (field $$tag (mut i32)))))
-//│   (type (func (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))))
-//│   (type (func (result (ref null any))))
-//│   (func  (type 1) (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))
+//│   (type $plus_impl (func (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))))
+//│   (type $entry1 (func (result (ref null any))))
+//│   (func  (type $plus_impl) (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))
 //│     (if (result (ref null any))
 //│       (i32.and
 //│         (ref.test (ref null i31)
@@ -27,7 +27,7 @@
 //│                 (local.get $rhs))))))
 //│       (else
 //│         (unreachable))))
-//│   (func $entry (type 2) (result (ref null any))
+//│   (func $entry (type $entry1) (result (ref null any))
 //│     (call 0
 //│       (ref.i31
 //│         (i32.const 1))
@@ -43,9 +43,9 @@
 //│ Wat:
 //│ (module
 //│   (type $Object (sub (struct (field $$tag (mut i32)))))
-//│   (type (func (param $arg (ref null any)) (result (ref null any))))
-//│   (type (func (result (ref null any))))
-//│   (func  (type 1) (param $arg (ref null any)) (result (ref null any))
+//│   (type $neg_impl (func (param $arg (ref null any)) (result (ref null any))))
+//│   (type $entry1 (func (result (ref null any))))
+//│   (func  (type $neg_impl) (param $arg (ref null any)) (result (ref null any))
 //│     (if (result (ref null any))
 //│       (ref.test (ref null i31)
 //│         (local.get $arg))
@@ -58,7 +58,7 @@
 //│                 (local.get $arg))))))
 //│       (else
 //│         (unreachable))))
-//│   (func $entry (type 2) (result (ref null any))
+//│   (func $entry (type $entry1) (result (ref null any))
 //│     (call 0
 //│       (ref.i31
 //│         (i32.const 2))))
@@ -92,9 +92,9 @@ not true
 //│ Wat:
 //│ (module
 //│   (type $Object (sub (struct (field $$tag (mut i32)))))
-//│   (type (func (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))))
-//│   (type (func (result (ref null any))))
-//│   (func  (type 1) (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))
+//│   (type $eq_impl (func (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))))
+//│   (type $entry1 (func (result (ref null any))))
+//│   (func  (type $eq_impl) (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))
 //│     (if (result (ref null any))
 //│       (i32.and
 //│         (ref.test (ref null i31)
@@ -112,7 +112,7 @@ not true
 //│                 (local.get $rhs))))))
 //│       (else
 //│         (unreachable))))
-//│   (func $entry (type 2) (result (ref null any))
+//│   (func $entry (type $entry1) (result (ref null any))
 //│     (call 0
 //│       (ref.i31
 //│         (i32.const 1))
diff --git a/hkmc2/shared/src/test/mlscript/wasm/ControlFlow.mls b/hkmc2/shared/src/test/mlscript/wasm/ControlFlow.mls
index a2e2077136..cc38e40a2f 100644
--- a/hkmc2/shared/src/test/mlscript/wasm/ControlFlow.mls
+++ b/hkmc2/shared/src/test/mlscript/wasm/ControlFlow.mls
@@ -10,15 +10,15 @@ let i = 0 in
 //│ Wat:
 //│ (module
 //│   (type $Object (sub (struct (field $$tag (mut i32)))))
-//│   (type (func (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))))
-//│   (type (func (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))))
+//│   (type $lt_impl (func (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))))
+//│   (type $plus_impl (func (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))))
 //│   (type $Unit (sub $Object (struct (field $$tag (mut i32)))))
 //│   (type $Unit_ctor (func (result (ref null any))))
-//│   (type (func (result (ref null any))))
+//│   (type $entry1 (func (result (ref null any))))
 //│   (type $start (func))
 //│   (global $Unit$inst (mut (ref null $Unit)) (ref.null $Unit))
 //│   (start 3)
-//│   (func  (type 1) (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))
+//│   (func  (type $lt_impl) (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))
 //│     (if (result (ref null any))
 //│       (i32.and
 //│         (ref.test (ref null i31)
@@ -36,7 +36,7 @@ let i = 0 in
 //│                 (local.get $rhs))))))
 //│       (else
 //│         (unreachable))))
-//│   (func  (type 2) (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))
+//│   (func  (type $plus_impl) (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))
 //│     (if (result (ref null any))
 //│       (i32.and
 //│         (ref.test (ref null i31)
@@ -71,7 +71,7 @@ let i = 0 in
 //│       (global.set $Unit$inst
 //│         (ref.cast (ref null $Unit)
 //│           (call 2)))))
-//│   (func $entry (type 5) (result (ref null any))
+//│   (func $entry (type $entry1) (result (ref null any))
 //│     (local $i (ref null any))
 //│     (local $scrut (ref null any))
 //│     (local $tmp (ref null any))
@@ -205,9 +205,9 @@ tailMatchAllValue(1)
 //│ Wat:
 //│ (module
 //│   (type $Object (sub (struct (field $$tag (mut i32)))))
-//│   (type (func (param $x (ref null any)) (result (ref null any))))
-//│   (type (func (result (ref null any))))
-//│   (func $tailMatchAllValue (type 1) (param $x (ref null any)) (result (ref null any))
+//│   (type $tailMatchAllValue1 (func (param $x (ref null any)) (result (ref null any))))
+//│   (type $entry1 (func (result (ref null any))))
+//│   (func $tailMatchAllValue (type $tailMatchAllValue1) (param $x (ref null any)) (result (ref null any))
 //│     (local $matchRes (ref null any))
 //│     (block (result (ref null any))
 //│       (block $match
@@ -243,11 +243,11 @@ tailMatchAllValue(1)
 //│       (local.get $matchRes)))
 //│   (export "tailMatchAllValue" (func $tailMatchAllValue))
 //│   (elem declare func $tailMatchAllValue)
-//│   (func $entry (type 2) (result (ref null any))
+//│   (func $entry (type $entry1) (result (ref null any))
 //│     (local $tailMatchAllValue (ref null any))
 //│     (block (result (ref null any))
 //│       (nop)
-//│       (call_ref 1
+//│       (call_ref $tailMatchAllValue1
 //│         (ref.i31
 //│           (i32.const 1))
 //│         (ref.func $tailMatchAllValue))))
diff --git a/hkmc2/shared/src/test/mlscript/wasm/Exceptions.mls b/hkmc2/shared/src/test/mlscript/wasm/Exceptions.mls
index 6547e2fe10..6a5a62d1ff 100644
--- a/hkmc2/shared/src/test/mlscript/wasm/Exceptions.mls
+++ b/hkmc2/shared/src/test/mlscript/wasm/Exceptions.mls
@@ -9,11 +9,11 @@ throw 1
 //│ Wat:
 //│ (module
 //│   (type $Object (sub (struct (field $$tag (mut i32)))))
-//│   (type (func (param (ref null any))))
-//│   (type (func (result (ref null any))))
-//│   (tag $mlx_exn (type 1))
+//│   (type $mlx_exn (func (param (ref null any))))
+//│   (type $entry1 (func (result (ref null any))))
+//│   (tag $mlx_exn (type $mlx_exn))
 //│   (export "mlx_exn" (tag $mlx_exn))
-//│   (func $entry (type 2) (result (ref null any))
+//│   (func $entry (type $entry1) (result (ref null any))
 //│     (throw $mlx_exn
 //│       (ref.i31
 //│         (i32.const 1))))
diff --git a/hkmc2/shared/src/test/mlscript/wasm/Matching.mls b/hkmc2/shared/src/test/mlscript/wasm/Matching.mls
index 5d96862b9b..f29e4217ea 100644
--- a/hkmc2/shared/src/test/mlscript/wasm/Matching.mls
+++ b/hkmc2/shared/src/test/mlscript/wasm/Matching.mls
@@ -46,10 +46,10 @@ if Bar(true) is
 //│   (type $Object (sub (struct (field $$tag (mut i32)))))
 //│   (type $Bar (sub $Object (struct (field $$tag (mut i32)) (field $y (mut (ref null any))))))
 //│   (type $Baz (sub $Object (struct (field $$tag (mut i32)) (field $z (mut (ref null any))))))
-//│   (type (func (param $y (ref null any)) (result (ref null any))))
-//│   (type (func (param $z (ref null any)) (result (ref null any))))
-//│   (type (func (result (ref null any))))
-//│   (func $Bar (type 3) (param $y (ref null any)) (result (ref null any))
+//│   (type $Bar_ctor (func (param $y (ref null any)) (result (ref null any))))
+//│   (type $Baz_ctor (func (param $z (ref null any)) (result (ref null any))))
+//│   (type $entry1 (func (result (ref null any))))
+//│   (func $Bar (type $Bar_ctor) (param $y (ref null any)) (result (ref null any))
 //│     (local $this (ref null any))
 //│     (block (result (ref null any))
 //│       (local.set $this
@@ -68,7 +68,7 @@ if Bar(true) is
 //│         (local.get $this))))
 //│   (export "Bar" (func $Bar))
 //│   (elem declare func $Bar)
-//│   (func $Baz (type 4) (param $z (ref null any)) (result (ref null any))
+//│   (func $Baz (type $Baz_ctor) (param $z (ref null any)) (result (ref null any))
 //│     (local $this (ref null any))
 //│     (block (result (ref null any))
 //│       (local.set $this
@@ -87,7 +87,7 @@ if Bar(true) is
 //│         (local.get $this))))
 //│   (export "Baz" (func $Baz))
 //│   (elem declare func $Baz)
-//│   (func $entry (type 5) (result (ref null any))
+//│   (func $entry (type $entry1) (result (ref null any))
 //│     (local $Bar (ref null any))
 //│     (local $Baz (ref null any))
 //│     (local $scrut (ref null any))
@@ -103,7 +103,7 @@ if Bar(true) is
 //│         (nop)
 //│         (block (result (ref null any))
 //│           (local.set $scrut
-//│             (call_ref 3
+//│             (call_ref $Bar_ctor
 //│               (ref.i31
 //│                 (i32.const 1))
 //│               (ref.func $Bar)))
diff --git a/hkmc2/shared/src/test/mlscript/wasm/ScopedLocals.mls b/hkmc2/shared/src/test/mlscript/wasm/ScopedLocals.mls
index 5b82a49b94..305e9d1cf2 100644
--- a/hkmc2/shared/src/test/mlscript/wasm/ScopedLocals.mls
+++ b/hkmc2/shared/src/test/mlscript/wasm/ScopedLocals.mls
@@ -10,9 +10,9 @@ topA + topB
 //│ Wat:
 //│ (module
 //│   (type $Object (sub (struct (field $$tag (mut i32)))))
-//│   (type (func (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))))
-//│   (type (func (result (ref null any))))
-//│   (func  (type 1) (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))
+//│   (type $plus_impl (func (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))))
+//│   (type $entry1 (func (result (ref null any))))
+//│   (func  (type $plus_impl) (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))
 //│     (if (result (ref null any))
 //│       (i32.and
 //│         (ref.test (ref null i31)
@@ -30,7 +30,7 @@ topA + topB
 //│                 (local.get $rhs))))))
 //│       (else
 //│         (unreachable))))
-//│   (func $entry (type 2) (result (ref null any))
+//│   (func $entry (type $entry1) (result (ref null any))
 //│     (local $topA (ref null any))
 //│     (local $topB (ref null any))
 //│     (block (result (ref null any))
@@ -59,10 +59,10 @@ chain(1)
 //│ Wat:
 //│ (module
 //│   (type $Object (sub (struct (field $$tag (mut i32)))))
-//│   (type (func (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))))
-//│   (type (func (param $x (ref null any)) (result (ref null any))))
-//│   (type (func (result (ref null any))))
-//│   (func  (type 1) (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))
+//│   (type $plus_impl (func (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))))
+//│   (type $chain1 (func (param $x (ref null any)) (result (ref null any))))
+//│   (type $entry1 (func (result (ref null any))))
+//│   (func  (type $plus_impl) (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))
 //│     (if (result (ref null any))
 //│       (i32.and
 //│         (ref.test (ref null i31)
@@ -80,7 +80,7 @@ chain(1)
 //│                 (local.get $rhs))))))
 //│       (else
 //│         (unreachable))))
-//│   (func $chain (type 2) (param $x (ref null any)) (result (ref null any))
+//│   (func $chain (type $chain1) (param $x (ref null any)) (result (ref null any))
 //│     (local $a (ref null any))
 //│     (local $b (ref null any))
 //│     (block (result (ref null any))
@@ -101,11 +101,11 @@ chain(1)
 //│             (local.get $b))))))
 //│   (export "chain" (func $chain))
 //│   (elem declare func $chain)
-//│   (func $entry (type 3) (result (ref null any))
+//│   (func $entry (type $entry1) (result (ref null any))
 //│     (local $chain (ref null any))
 //│     (block (result (ref null any))
 //│       (nop)
-//│       (call_ref 2
+//│       (call_ref $chain1
 //│         (ref.i31
 //│           (i32.const 1))
 //│         (ref.func $chain))))
@@ -169,9 +169,9 @@ class Foo(val a, val b)
 //│ (module
 //│   (type $Object (sub (struct (field $$tag (mut i32)))))
 //│   (type $Foo (sub $Object (struct (field $$tag (mut i32)) (field $a (mut (ref null any))) (field $b (mut (ref null any))))))
-//│   (type (func (param $a (ref null any)) (param $b (ref null any)) (result (ref null any))))
-//│   (type (func (result (ref null any))))
-//│   (func $Foo (type 2) (param $a (ref null any)) (param $b (ref null any)) (result (ref null any))
+//│   (type $Foo_ctor (func (param $a (ref null any)) (param $b (ref null any)) (result (ref null any))))
+//│   (type $entry1 (func (result (ref null any))))
+//│   (func $Foo (type $Foo_ctor) (param $a (ref null any)) (param $b (ref null any)) (result (ref null any))
 //│     (local $this (ref null any))
 //│     (block (result (ref null any))
 //│       (local.set $this
@@ -195,7 +195,7 @@ class Foo(val a, val b)
 //│         (local.get $this))))
 //│   (export "Foo" (func $Foo))
 //│   (elem declare func $Foo)
-//│   (func $entry (type 3) (result (ref null any))
+//│   (func $entry (type $entry1) (result (ref null any))
 //│     (local $Foo (ref null any))
 //│     (local $tmp (ref null any))
 //│     (block (result (ref null any))
diff --git a/hkmc2/shared/src/test/mlscript/wasm/SingletonUnit.mls b/hkmc2/shared/src/test/mlscript/wasm/SingletonUnit.mls
index 7538ec47ea..b4ed1cf248 100644
--- a/hkmc2/shared/src/test/mlscript/wasm/SingletonUnit.mls
+++ b/hkmc2/shared/src/test/mlscript/wasm/SingletonUnit.mls
@@ -9,7 +9,7 @@
 //│   (type $Object (sub (struct (field $$tag (mut i32)))))
 //│   (type $Unit (sub $Object (struct (field $$tag (mut i32)))))
 //│   (type $Unit_ctor (func (result (ref null any))))
-//│   (type (func (result (ref null any))))
+//│   (type $entry1 (func (result (ref null any))))
 //│   (type $start (func))
 //│   (global $Unit$inst (mut (ref null $Unit)) (ref.null $Unit))
 //│   (start 1)
@@ -30,7 +30,7 @@
 //│       (global.set $Unit$inst
 //│         (ref.cast (ref null $Unit)
 //│           (call 0)))))
-//│   (func $entry (type 3) (result (ref null any))
+//│   (func $entry (type $entry1) (result (ref null any))
 //│     (global.get $Unit$inst))
 //│   (export "entry" (func $entry))
 //│   (elem declare func $entry))
@@ -74,8 +74,8 @@ x
 //│ Wat:
 //│ (module
 //│   (type $Object (sub (struct (field $$tag (mut i32)))))
-//│   (type (func (result (ref null any))))
-//│   (func $entry (type 1) (result (ref null any))
+//│   (type $entry1 (func (result (ref null any))))
+//│   (func $entry (type $entry1) (result (ref null any))
 //│     (local $x (ref null any))
 //│     (block (result (ref null any))
 //│       (local.set $x
diff --git a/hkmc2/shared/src/test/mlscript/wasm/Singletons.mls b/hkmc2/shared/src/test/mlscript/wasm/Singletons.mls
index ec60b20877..d0459ea7f7 100644
--- a/hkmc2/shared/src/test/mlscript/wasm/Singletons.mls
+++ b/hkmc2/shared/src/test/mlscript/wasm/Singletons.mls
@@ -16,7 +16,7 @@ Bar.y
 //│   (type $Bar (sub $Object (struct (field $$tag (mut i32)) (field $y (mut (ref null any))))))
 //│   (type $Foo_ctor (func (result (ref null any))))
 //│   (type $Bar_ctor (func (result (ref null any))))
-//│   (type (func (result (ref null any))))
+//│   (type $entry1 (func (result (ref null any))))
 //│   (type $start (func))
 //│   (global $Foo$inst (mut (ref null $Foo)) (ref.null $Foo))
 //│   (global $Bar$inst (mut (ref null $Bar)) (ref.null $Bar))
@@ -65,7 +65,7 @@ Bar.y
 //│       (global.set $Bar$inst
 //│         (ref.cast (ref null $Bar)
 //│           (call 1)))))
-//│   (func $entry (type 5) (result (ref null any))
+//│   (func $entry (type $entry1) (result (ref null any))
 //│     (local $Bar (ref null any))
 //│     (local $Foo (ref null any))
 //│     (block (result (ref null any))
diff --git a/hkmc2/shared/src/test/mlscript/wasm/Strings.mls b/hkmc2/shared/src/test/mlscript/wasm/Strings.mls
index 03ad153054..d3620df5bb 100644
--- a/hkmc2/shared/src/test/mlscript/wasm/Strings.mls
+++ b/hkmc2/shared/src/test/mlscript/wasm/Strings.mls
@@ -17,14 +17,14 @@ let dup2 = "dup"
 //│ Wat:
 //│ (module
 //│   (type $Object (sub (struct (field $$tag (mut i32)))))
-//│   (type (func (param (ref null any)) (param (ref null any)) (result (ref null any))))
+//│   (type $mlx_str_from_utf16 (func (param (ref null any)) (param (ref null any)) (result (ref null any))))
 //│   (type $TupleArray (array (ref null any)))
 //│   (type $TupleArrayMut (array (mut (ref null any))))
-//│   (type (func (result (ref null any))))
+//│   (type $entry1 (func (result (ref null any))))
 //│   (import "system" "mem" (memory 1))
-//│   (import "system" "mlx_str_from_utf16" (func $mlx_str_from_utf16 (type 1)))
+//│   (import "system" "mlx_str_from_utf16" (func $mlx_str_from_utf16 (type $mlx_str_from_utf16)))
 //│   (data (i32.const 0) "\64\00\75\00\70\00")
-//│   (func $entry (type 4) (result (ref null any))
+//│   (func $entry (type $entry1) (result (ref null any))
 //│     (local $dup1 (ref null any))
 //│     (local $dup2 (ref null any))
 //│     (local $tmp (ref null any))
diff --git a/hkmc2/shared/src/test/mlscript/wasm/Tuples.mls b/hkmc2/shared/src/test/mlscript/wasm/Tuples.mls
index 0636d511d2..46025df1cf 100644
--- a/hkmc2/shared/src/test/mlscript/wasm/Tuples.mls
+++ b/hkmc2/shared/src/test/mlscript/wasm/Tuples.mls
@@ -54,8 +54,8 @@ c.[3]
 //│   (type $Object (sub (struct (field $$tag (mut i32)))))
 //│   (type $TupleArray (array (ref null any)))
 //│   (type $TupleArrayMut (array (mut (ref null any))))
-//│   (type (func (result (ref null any))))
-//│   (func $entry (type 3) (result (ref null any))
+//│   (type $entry1 (func (result (ref null any))))
+//│   (func $entry (type $entry1) (result (ref null any))
 //│     (local $c (ref null any))
 //│     (local $tuple (ref null any))
 //│     (block (result (ref null any))

From 747f64949dc08843399db60bad8d163e78f36d5c Mon Sep 17 00:00:00 2001
From: David Mak <david.18.19.21@gmail.com>
Date: Sat, 14 Mar 2026 01:06:30 +0800
Subject: [PATCH 06/16] wasm: Make symbolic index for functions mandatory

---
 .../scala/hkmc2/codegen/wasm/text/Ctx.scala   | 75 ++++++++++++++-----
 .../hkmc2/codegen/wasm/text/WatBuilder.scala  | 31 +++++---
 .../shared/src/test/mlscript/wasm/Basics.mls  | 29 +++----
 .../test/mlscript/wasm/BuiltinOperators.mls   | 15 ++--
 .../src/test/mlscript/wasm/ControlFlow.mls    | 18 +++--
 .../src/test/mlscript/wasm/Matching.mls       | 14 ++--
 .../src/test/mlscript/wasm/ScopedLocals.mls   | 22 +++---
 .../src/test/mlscript/wasm/SingletonUnit.mls  |  8 +-
 .../src/test/mlscript/wasm/Singletons.mls     | 11 ++-
 9 files changed, 145 insertions(+), 78 deletions(-)

diff --git a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala
index df9280ab60..5524c4ac6e 100644
--- a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala
+++ b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala
@@ -30,14 +30,17 @@ import scala.collection.mutable.{ArrayBuffer as ArrayBuf, Map as MutMap}
   *   [[Seq]] of local variables (excluding parameters) and their names.
   * @param body
   *   The expression of the function body.
+  * @param exports
+  *   [[Seq]] of export names for the function.
   */
 class FuncInfo(
-    val id: Opt[SymIdx],
+    val id: SymIdx,
     val typeIdx: TypeIdx,
     params: Seq[Local -> Str],
     nResults: Int,
     locals: Seq[Local -> Str],
     val body: Expr,
+    val exports: Seq[Str],
 ) extends ToWat:
 
   /** @param sym
@@ -60,13 +63,33 @@ class FuncInfo(
       nResults: Int,
       locals: Seq[Local -> Str],
       body: Expr,
-  ) = this(
-    sym.optionIf(_.nameIsMeaningful).map(sym => SymIdx(sym.nme)),
+  )(using Raise, Scope) = this(
+    SymIdx(sym.optionIf(_.nameIsMeaningful).fold(summon[Scope].allocateName(sym))(_.nme)),
+    typeIdx,
+    params,
+    nResults,
+    locals,
+    body,
+    sym.optionIf(_.nameIsMeaningful).map(_.nme).toSeq,
+  )
+
+  @deprecated("Consider providing a symbolic identifier by using `Scope.allocateName` with a `TempSymbol`.")
+  def this(
+      id: Opt[SymIdx],
+      typeIdx: TypeIdx,
+      params: Seq[Local -> Str],
+      nResults: Int,
+      locals: Seq[Local -> Str],
+      body: Expr,
+      exports: Seq[Str],
+  )(using Raise, Scope, State) = this(
+    id.getOrElse(SymIdx(summon[Scope].allocateName(TempSymbol(N, "")))),
     typeIdx,
     params,
     nResults,
     locals,
     body,
+    exports,
   )
 
   /** Returns the type of this function as a [[SignatureType]]. */
@@ -76,16 +99,19 @@ class FuncInfo(
   )
 
   def toWat: Document =
-    doc"""(func ${id.fold(doc"")(_.toWat)} (type ${typeIdx.toWat})${
+    // TODO(Derppening): Make exports configurable
+    doc"""(func ${id.toWat} (type ${typeIdx.toWat})${
         getSignatureType.toWat.surroundUnlessEmpty(doc" ")
       } #{ ${
         locals.map: p =>
           doc"(local $$${p._2} ${RefType.anyref.toWat})"
         .mkDocument(doc" # ").surroundUnlessEmpty(doc" # ")
       } # ${body.toWat} #} )${
-        id.fold(doc""): id =>
-          doc""" # (export "${id.id}" (func ${id.toWat})) # (elem declare func ${id.toWat})"""
-      }"""
+        exports
+          .map: e =>
+            doc""" # (export "${e}" (func ${id.toWat}))"""
+          .mkDocument(doc"")
+      } # (elem declare func ${id.toWat})"""
 end FuncInfo
 
 /** A Wasm global and its associated information.
@@ -337,7 +363,7 @@ class Ctx(
     funcInfosByIndex(numIdx) = funcInfo
     sym.foreach:
       namedFuncs(_) = numIdx
-    FuncIdx(funcInfo.id.getOrElse(NumIdx(numIdx)))
+    FuncIdx(funcInfo.id)
 
   /** Adds a function import into this context.
     *
@@ -387,29 +413,42 @@ class Ctx(
     tags += tagInfo
     TagIdx(tagInfo.id)
 
+  @deprecated("Use the overload without `resolveSymIdx` instead.")
+  def getFunc(funcref: FuncIdx | Symbol, resolveSymIdx: Bool): Opt[FuncIdx] =
+    if resolveSymIdx then
+      funcref match
+        case FuncIdx(SymIdx(nme)) if resolveSymIdx =>
+          namedFuncs.find(_._1.nme == nme).map(f => FuncIdx(NumIdx(f._2)))
+        case funcidx: FuncIdx => S(funcidx)
+        case sym: Symbol => namedFuncs.get(sym).map(idx => FuncIdx(NumIdx(idx)))
+    else getFunc(funcref)
+
   /** Returns the [[FuncIdx]] of the given `funcref`, optionally resolving the symbolic index into a numeric index.
     */
-  def getFunc(funcref: FuncIdx | Symbol, resolveSymIdx: Bool = false): Opt[FuncIdx] = funcref match
-    case FuncIdx(SymIdx(nme)) if resolveSymIdx =>
-      namedFuncs.find(_._1.nme == nme).map(f => FuncIdx(NumIdx(f._2)))
+  def getFunc(funcref: FuncIdx | Symbol): Opt[FuncIdx] = funcref match
     case funcidx: FuncIdx => S(funcidx)
-    case sym: Symbol if resolveSymIdx => namedFuncs.get(sym).map(idx => FuncIdx(NumIdx(idx)))
-    case sym: Symbol =>
-      getFunc(sym, resolveSymIdx = true).map: numIdx =>
-        getFuncInfo(numIdx).flatMap(_.id).fold(numIdx)(FuncIdx(_))
+    case sym: Symbol => getFuncInfo(funcref).map(fi => FuncIdx(fi.id))
 
-  /** Same as [[getFunc]] but throws an exception when the `funcref` is not found. */
-  def getFunc_!(funcref: FuncIdx | Symbol, resolveSymIdx: Bool = false): FuncIdx =
+  @deprecated("Use the overload without `resolveSymIdx` instead.")
+  def getFunc_!(funcref: FuncIdx | Symbol, resolveSymIdx: Bool): FuncIdx =
     getFunc(funcref, resolveSymIdx).getOrElse:
       lastWords(s"Missing function definition for ${funcref.prettyString}")
 
+  /** Same as [[getFunc]] but throws an exception when the `funcref` is not found. */
+  def getFunc_!(funcref: FuncIdx | Symbol): FuncIdx =
+    getFunc(funcref).getOrElse:
+      lastWords(s"Missing function definition for ${funcref.prettyString}")
+
   /** Returns the [[FuncInfo]] instance associated with the given `funcref`. */
   def getFuncInfo(funcref: FuncIdx | Symbol): Opt[FuncInfo] = funcref match
     case FuncIdx(NumIdx(idx)) =>
       funcInfosByIndex.get(idx).orElse:
         val localIdx = idx.toInt - functionImports.size
         if localIdx < 0 then N else funcs.unapply(localIdx)
-    case funcref => getFunc(funcref, resolveSymIdx = true).flatMap(getFuncInfo(_))
+    case FuncIdx(SymIdx(nme)) =>
+      // TODO(Derppening): Consider adding a `Map[SymIdx, TypeInfo]` for faster lookup
+      funcs.find(_.id.id == nme)
+    case funcref: Symbol => namedFuncs.get(funcref).map(idx => funcs(idx))
 
   /** Same as [[getFuncInfo]] but throws an exception when the `funcref` is not found. */
   def getFuncInfo_!(funcref: FuncIdx | Symbol): FuncInfo =
diff --git a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala
index 4142324682..22fe140438 100644
--- a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala
+++ b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala
@@ -786,12 +786,13 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
       ),
     )
     val funcInfo = FuncInfo(
-      id = N,
+      id = SymIdx(scope.allocateName(TempSymbol(N, name))),
       typeIdx = funcTy,
       params = params,
       nResults = 1,
       locals = Seq.empty,
       body = body,
+      exports = Seq.empty,
     )
     ctx.addFunc(N, funcInfo)
   end createIntrinsicFunc
@@ -1117,9 +1118,13 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
                     else
                       break(errUnimplExpr("newCtorAuxParams.nonEmpty"))
 
-                    val funcTyId =
-                      if isSingletonObj then s"${clsLikeDefn.sym.nme}_ctor"
-                      else scope.allocateName(TempSymbol(N, s"${clsLikeDefn.sym.nme}_ctor"))
+                    val funcTyId = clsLikeDefn.sym
+                      .optionIf: sym =>
+                        !isSingletonObj && sym.nameIsMeaningful
+                      .map: sym =>
+                        s"${sym.nme}_ctor"
+                      .getOrElse:
+                        scope.allocateName(TempSymbol(N, s"${clsLikeDefn.sym.nme}_ctor"))
                     val funcTy = ctx.addType(
                       sym = N,
                       TypeInfo(
@@ -1131,18 +1136,22 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
                       ),
                     )
 
-                    val ctorId =
-                      if isSingletonObj then N
-                      else clsLikeDefn.sym.optionIf(_.nameIsMeaningful).map(sym => SymIdx(sym.nme))
+                    val ctorId = clsLikeDefn.sym
+                      .optionIf: sym =>
+                        !isSingletonObj && sym.nameIsMeaningful
+                      .map: sym =>
+                        s"${sym.nme}_ctor"
                     ctx.addFunc(
                       S(clsLikeDefn.sym),
                       FuncInfo(
-                        id = ctorId,
+                        id =
+                          SymIdx(ctorId.getOrElse(scope.allocateName(TempSymbol(N, s"${clsLikeDefn.sym.nme}_ctor")))),
                         typeIdx = funcTy,
                         params = ctorParams,
                         nResults = ctorCode.resultTypes.length,
                         locals = ctorLocals,
                         body = ctorAux,
+                        exports = ctorId.toSeq,
                       ),
                     )
                     if isSingletonObj then
@@ -1517,13 +1526,14 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
       ),
     )
     val entryFnInfo = FuncInfo(
-      id = S(SymIdx(entryNme)),
+      id = SymIdx(entryNme),
       typeIdx = entryFnTy,
       params = Seq.empty,
       nResults = 1,
       // TODO(Derppening): Should we place top-level scope variables in the global section?
       locals = (entryFnLocals ++ entryExtraLocals).map(l => l -> scope.allocateOrGetName(l)),
       body = entryFnExpr,
+      exports = Seq(entryNme),
     )
 
     ctx.popLocal()
@@ -1549,12 +1559,13 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
       val initFn = ctx.addFunc(
         sym = N,
         FuncInfo(
-          id = N,
+          id = SymIdx(scope.allocateName(TempSymbol(N, "start"))),
           typeIdx = initTy,
           params = Seq.empty,
           nResults = 0,
           locals = Seq.empty,
           body = initBody,
+          exports = Seq.empty,
         ),
       )
       ctx.setStartFunc(initFn)
diff --git a/hkmc2/shared/src/test/mlscript/wasm/Basics.mls b/hkmc2/shared/src/test/mlscript/wasm/Basics.mls
index c449e8a9ac..f859d76b9b 100644
--- a/hkmc2/shared/src/test/mlscript/wasm/Basics.mls
+++ b/hkmc2/shared/src/test/mlscript/wasm/Basics.mls
@@ -58,7 +58,7 @@ foo() + foo()
 //│         (i32.const 42))))
 //│   (export "foo" (func $foo))
 //│   (elem declare func $foo)
-//│   (func  (type $plus_impl) (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))
+//│   (func $plus_impl1 (type $plus_impl) (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))
 //│     (if (result (ref null any))
 //│       (i32.and
 //│         (ref.test (ref null i31)
@@ -76,6 +76,7 @@ foo() + foo()
 //│                 (local.get $rhs))))))
 //│       (else
 //│         (unreachable))))
+//│   (elem declare func $plus_impl1)
 //│   (func $entry (type $entry1) (result (ref null any))
 //│     (local $foo (ref null any))
 //│     (local $tmp (ref null any))
@@ -90,7 +91,7 @@ foo() + foo()
 //│           (local.set $tmp1
 //│             (call_ref $foo1
 //│               (ref.func $foo)))
-//│           (call 1
+//│           (call $plus_impl1
 //│             (local.get $tmp)
 //│             (local.get $tmp1))))))
 //│   (export "entry" (func $entry))
@@ -120,7 +121,7 @@ class Foo(val a)
 //│   (type $Foo (sub $Object (struct (field $$tag (mut i32)) (field $a (mut (ref null any))))))
 //│   (type $Foo_ctor (func (param $a (ref null any)) (result (ref null any))))
 //│   (type $entry1 (func (result (ref null any))))
-//│   (func $Foo (type $Foo_ctor) (param $a (ref null any)) (result (ref null any))
+//│   (func $Foo_ctor (type $Foo_ctor) (param $a (ref null any)) (result (ref null any))
 //│     (local $this (ref null any))
 //│     (block (result (ref null any))
 //│       (local.set $this
@@ -137,8 +138,8 @@ class Foo(val a)
 //│         (nop))
 //│       (return
 //│         (local.get $this))))
-//│   (export "Foo" (func $Foo))
-//│   (elem declare func $Foo)
+//│   (export "Foo_ctor" (func $Foo_ctor))
+//│   (elem declare func $Foo_ctor)
 //│   (func $entry (type $entry1) (result (ref null any))
 //│     (local $Foo (ref null any))
 //│     (local $tmp (ref null any))
@@ -146,7 +147,7 @@ class Foo(val a)
 //│       (nop)
 //│       (block (result (ref null any))
 //│         (local.set $tmp
-//│           (call $Foo
+//│           (call $Foo_ctor
 //│             (ref.i31
 //│               (i32.const 42))))
 //│         (struct.get $Foo $a
@@ -174,7 +175,7 @@ class Foo(val x) with
 //│   (type $Foo (sub $Object (struct (field $$tag (mut i32)) (field $x (mut (ref null any))) (field $y (mut (ref null any))))))
 //│   (type $Foo_ctor (func (param $x (ref null any)) (result (ref null any))))
 //│   (type $entry1 (func (result (ref null any))))
-//│   (func $Foo (type $Foo_ctor) (param $x (ref null any)) (result (ref null any))
+//│   (func $Foo_ctor (type $Foo_ctor) (param $x (ref null any)) (result (ref null any))
 //│     (local $this (ref null any))
 //│     (block (result (ref null any))
 //│       (local.set $this
@@ -198,8 +199,8 @@ class Foo(val x) with
 //│           (nop)))
 //│       (return
 //│         (local.get $this))))
-//│   (export "Foo" (func $Foo))
-//│   (elem declare func $Foo)
+//│   (export "Foo_ctor" (func $Foo_ctor))
+//│   (elem declare func $Foo_ctor)
 //│   (func $entry (type $entry1) (result (ref null any))
 //│     (local $Foo (ref null any))
 //│     (local $tmp (ref null any))
@@ -207,7 +208,7 @@ class Foo(val x) with
 //│       (nop)
 //│       (block (result (ref null any))
 //│         (local.set $tmp
-//│           (call $Foo
+//│           (call $Foo_ctor
 //│             (ref.i31
 //│               (i32.const 42))))
 //│         (struct.get $Foo $y
@@ -232,8 +233,8 @@ O.y
 //│   (type $entry1 (func (result (ref null any))))
 //│   (type $start (func))
 //│   (global $O$inst (mut (ref null $O)) (ref.null $O))
-//│   (start 1)
-//│   (func  (type $O_ctor) (result (ref null any))
+//│   (start $start1)
+//│   (func $O_ctor1 (type $O_ctor) (result (ref null any))
 //│     (local $this (ref null any))
 //│     (block (result (ref null any))
 //│       (local.set $this
@@ -258,11 +259,13 @@ O.y
 //│           (nop)))
 //│       (return
 //│         (local.get $this))))
-//│   (func  (type $start)
+//│   (elem declare func $O_ctor1)
+//│   (func $start1 (type $start)
 //│     (block
 //│       (global.set $O$inst
 //│         (ref.cast (ref null $O)
 //│           (call 0)))))
+//│   (elem declare func $start1)
 //│   (func $entry (type $entry1) (result (ref null any))
 //│     (local $O (ref null any))
 //│     (block (result (ref null any))
diff --git a/hkmc2/shared/src/test/mlscript/wasm/BuiltinOperators.mls b/hkmc2/shared/src/test/mlscript/wasm/BuiltinOperators.mls
index 21e9c29e75..cce0c48ed4 100644
--- a/hkmc2/shared/src/test/mlscript/wasm/BuiltinOperators.mls
+++ b/hkmc2/shared/src/test/mlscript/wasm/BuiltinOperators.mls
@@ -9,7 +9,7 @@
 //│   (type $Object (sub (struct (field $$tag (mut i32)))))
 //│   (type $plus_impl (func (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))))
 //│   (type $entry1 (func (result (ref null any))))
-//│   (func  (type $plus_impl) (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))
+//│   (func $plus_impl1 (type $plus_impl) (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))
 //│     (if (result (ref null any))
 //│       (i32.and
 //│         (ref.test (ref null i31)
@@ -27,8 +27,9 @@
 //│                 (local.get $rhs))))))
 //│       (else
 //│         (unreachable))))
+//│   (elem declare func $plus_impl1)
 //│   (func $entry (type $entry1) (result (ref null any))
-//│     (call 0
+//│     (call $plus_impl1
 //│       (ref.i31
 //│         (i32.const 1))
 //│       (ref.i31
@@ -45,7 +46,7 @@
 //│   (type $Object (sub (struct (field $$tag (mut i32)))))
 //│   (type $neg_impl (func (param $arg (ref null any)) (result (ref null any))))
 //│   (type $entry1 (func (result (ref null any))))
-//│   (func  (type $neg_impl) (param $arg (ref null any)) (result (ref null any))
+//│   (func $neg_impl1 (type $neg_impl) (param $arg (ref null any)) (result (ref null any))
 //│     (if (result (ref null any))
 //│       (ref.test (ref null i31)
 //│         (local.get $arg))
@@ -58,8 +59,9 @@
 //│                 (local.get $arg))))))
 //│       (else
 //│         (unreachable))))
+//│   (elem declare func $neg_impl1)
 //│   (func $entry (type $entry1) (result (ref null any))
-//│     (call 0
+//│     (call $neg_impl1
 //│       (ref.i31
 //│         (i32.const 2))))
 //│   (export "entry" (func $entry))
@@ -94,7 +96,7 @@ not true
 //│   (type $Object (sub (struct (field $$tag (mut i32)))))
 //│   (type $eq_impl (func (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))))
 //│   (type $entry1 (func (result (ref null any))))
-//│   (func  (type $eq_impl) (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))
+//│   (func $eq_impl1 (type $eq_impl) (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))
 //│     (if (result (ref null any))
 //│       (i32.and
 //│         (ref.test (ref null i31)
@@ -112,8 +114,9 @@ not true
 //│                 (local.get $rhs))))))
 //│       (else
 //│         (unreachable))))
+//│   (elem declare func $eq_impl1)
 //│   (func $entry (type $entry1) (result (ref null any))
-//│     (call 0
+//│     (call $eq_impl1
 //│       (ref.i31
 //│         (i32.const 1))
 //│       (ref.i31
diff --git a/hkmc2/shared/src/test/mlscript/wasm/ControlFlow.mls b/hkmc2/shared/src/test/mlscript/wasm/ControlFlow.mls
index cc38e40a2f..5256d15409 100644
--- a/hkmc2/shared/src/test/mlscript/wasm/ControlFlow.mls
+++ b/hkmc2/shared/src/test/mlscript/wasm/ControlFlow.mls
@@ -17,8 +17,8 @@ let i = 0 in
 //│   (type $entry1 (func (result (ref null any))))
 //│   (type $start (func))
 //│   (global $Unit$inst (mut (ref null $Unit)) (ref.null $Unit))
-//│   (start 3)
-//│   (func  (type $lt_impl) (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))
+//│   (start $start1)
+//│   (func $lt_impl1 (type $lt_impl) (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))
 //│     (if (result (ref null any))
 //│       (i32.and
 //│         (ref.test (ref null i31)
@@ -36,7 +36,8 @@ let i = 0 in
 //│                 (local.get $rhs))))))
 //│       (else
 //│         (unreachable))))
-//│   (func  (type $plus_impl) (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))
+//│   (elem declare func $lt_impl1)
+//│   (func $plus_impl1 (type $plus_impl) (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))
 //│     (if (result (ref null any))
 //│       (i32.and
 //│         (ref.test (ref null i31)
@@ -54,7 +55,8 @@ let i = 0 in
 //│                 (local.get $rhs))))))
 //│       (else
 //│         (unreachable))))
-//│   (func  (type $Unit_ctor) (result (ref null any))
+//│   (elem declare func $plus_impl1)
+//│   (func $Unit_ctor1 (type $Unit_ctor) (result (ref null any))
 //│     (local $this (ref null any))
 //│     (block (result (ref null any))
 //│       (local.set $this
@@ -66,11 +68,13 @@ let i = 0 in
 //│       (nop)
 //│       (return
 //│         (local.get $this))))
-//│   (func  (type $start)
+//│   (elem declare func $Unit_ctor1)
+//│   (func $start1 (type $start)
 //│     (block
 //│       (global.set $Unit$inst
 //│         (ref.cast (ref null $Unit)
 //│           (call 2)))))
+//│   (elem declare func $start1)
 //│   (func $entry (type $entry1) (result (ref null any))
 //│     (local $i (ref null any))
 //│     (local $scrut (ref null any))
@@ -86,7 +90,7 @@ let i = 0 in
 //│             (drop
 //│               (block (result (ref null any))
 //│                 (local.set $scrut
-//│                   (call 0
+//│                   (call $lt_impl1
 //│                     (local.get $i)
 //│                     (ref.i31
 //│                       (i32.const 10))))
@@ -105,7 +109,7 @@ let i = 0 in
 //│                           (block
 //│                             (block
 //│                               (local.set $tmp
-//│                                 (call 1
+//│                                 (call $plus_impl1
 //│                                   (local.get $i)
 //│                                   (ref.i31
 //│                                     (i32.const 1))))
diff --git a/hkmc2/shared/src/test/mlscript/wasm/Matching.mls b/hkmc2/shared/src/test/mlscript/wasm/Matching.mls
index f29e4217ea..ee364b6293 100644
--- a/hkmc2/shared/src/test/mlscript/wasm/Matching.mls
+++ b/hkmc2/shared/src/test/mlscript/wasm/Matching.mls
@@ -49,7 +49,7 @@ if Bar(true) is
 //│   (type $Bar_ctor (func (param $y (ref null any)) (result (ref null any))))
 //│   (type $Baz_ctor (func (param $z (ref null any)) (result (ref null any))))
 //│   (type $entry1 (func (result (ref null any))))
-//│   (func $Bar (type $Bar_ctor) (param $y (ref null any)) (result (ref null any))
+//│   (func $Bar_ctor (type $Bar_ctor) (param $y (ref null any)) (result (ref null any))
 //│     (local $this (ref null any))
 //│     (block (result (ref null any))
 //│       (local.set $this
@@ -66,9 +66,9 @@ if Bar(true) is
 //│         (nop))
 //│       (return
 //│         (local.get $this))))
-//│   (export "Bar" (func $Bar))
-//│   (elem declare func $Bar)
-//│   (func $Baz (type $Baz_ctor) (param $z (ref null any)) (result (ref null any))
+//│   (export "Bar_ctor" (func $Bar_ctor))
+//│   (elem declare func $Bar_ctor)
+//│   (func $Baz_ctor (type $Baz_ctor) (param $z (ref null any)) (result (ref null any))
 //│     (local $this (ref null any))
 //│     (block (result (ref null any))
 //│       (local.set $this
@@ -85,8 +85,8 @@ if Bar(true) is
 //│         (nop))
 //│       (return
 //│         (local.get $this))))
-//│   (export "Baz" (func $Baz))
-//│   (elem declare func $Baz)
+//│   (export "Baz_ctor" (func $Baz_ctor))
+//│   (elem declare func $Baz_ctor)
 //│   (func $entry (type $entry1) (result (ref null any))
 //│     (local $Bar (ref null any))
 //│     (local $Baz (ref null any))
@@ -106,7 +106,7 @@ if Bar(true) is
 //│             (call_ref $Bar_ctor
 //│               (ref.i31
 //│                 (i32.const 1))
-//│               (ref.func $Bar)))
+//│               (ref.func $Bar_ctor)))
 //│           (block (result (ref null any))
 //│             (block $match
 //│               (local.set $matchRes
diff --git a/hkmc2/shared/src/test/mlscript/wasm/ScopedLocals.mls b/hkmc2/shared/src/test/mlscript/wasm/ScopedLocals.mls
index 305e9d1cf2..113985457a 100644
--- a/hkmc2/shared/src/test/mlscript/wasm/ScopedLocals.mls
+++ b/hkmc2/shared/src/test/mlscript/wasm/ScopedLocals.mls
@@ -12,7 +12,7 @@ topA + topB
 //│   (type $Object (sub (struct (field $$tag (mut i32)))))
 //│   (type $plus_impl (func (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))))
 //│   (type $entry1 (func (result (ref null any))))
-//│   (func  (type $plus_impl) (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))
+//│   (func $plus_impl1 (type $plus_impl) (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))
 //│     (if (result (ref null any))
 //│       (i32.and
 //│         (ref.test (ref null i31)
@@ -30,6 +30,7 @@ topA + topB
 //│                 (local.get $rhs))))))
 //│       (else
 //│         (unreachable))))
+//│   (elem declare func $plus_impl1)
 //│   (func $entry (type $entry1) (result (ref null any))
 //│     (local $topA (ref null any))
 //│     (local $topB (ref null any))
@@ -41,7 +42,7 @@ topA + topB
 //│         (local.set $topB
 //│           (ref.i31
 //│             (i32.const 2)))
-//│         (call 0
+//│         (call $plus_impl1
 //│           (local.get $topA)
 //│           (local.get $topB)))))
 //│   (export "entry" (func $entry))
@@ -62,7 +63,7 @@ chain(1)
 //│   (type $plus_impl (func (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))))
 //│   (type $chain1 (func (param $x (ref null any)) (result (ref null any))))
 //│   (type $entry1 (func (result (ref null any))))
-//│   (func  (type $plus_impl) (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))
+//│   (func $plus_impl1 (type $plus_impl) (param $lhs (ref null any)) (param $rhs (ref null any)) (result (ref null any))
 //│     (if (result (ref null any))
 //│       (i32.and
 //│         (ref.test (ref null i31)
@@ -80,23 +81,24 @@ chain(1)
 //│                 (local.get $rhs))))))
 //│       (else
 //│         (unreachable))))
+//│   (elem declare func $plus_impl1)
 //│   (func $chain (type $chain1) (param $x (ref null any)) (result (ref null any))
 //│     (local $a (ref null any))
 //│     (local $b (ref null any))
 //│     (block (result (ref null any))
 //│       (local.set $a
-//│         (call 0
+//│         (call $plus_impl1
 //│           (local.get $x)
 //│           (ref.i31
 //│             (i32.const 1))))
 //│       (block (result (ref null any))
 //│         (local.set $b
-//│           (call 0
+//│           (call $plus_impl1
 //│             (local.get $a)
 //│             (ref.i31
 //│               (i32.const 1))))
 //│         (return
-//│           (call 0
+//│           (call $plus_impl1
 //│             (local.get $a)
 //│             (local.get $b))))))
 //│   (export "chain" (func $chain))
@@ -171,7 +173,7 @@ class Foo(val a, val b)
 //│   (type $Foo (sub $Object (struct (field $$tag (mut i32)) (field $a (mut (ref null any))) (field $b (mut (ref null any))))))
 //│   (type $Foo_ctor (func (param $a (ref null any)) (param $b (ref null any)) (result (ref null any))))
 //│   (type $entry1 (func (result (ref null any))))
-//│   (func $Foo (type $Foo_ctor) (param $a (ref null any)) (param $b (ref null any)) (result (ref null any))
+//│   (func $Foo_ctor (type $Foo_ctor) (param $a (ref null any)) (param $b (ref null any)) (result (ref null any))
 //│     (local $this (ref null any))
 //│     (block (result (ref null any))
 //│       (local.set $this
@@ -193,8 +195,8 @@ class Foo(val a, val b)
 //│           (nop)))
 //│       (return
 //│         (local.get $this))))
-//│   (export "Foo" (func $Foo))
-//│   (elem declare func $Foo)
+//│   (export "Foo_ctor" (func $Foo_ctor))
+//│   (elem declare func $Foo_ctor)
 //│   (func $entry (type $entry1) (result (ref null any))
 //│     (local $Foo (ref null any))
 //│     (local $tmp (ref null any))
@@ -202,7 +204,7 @@ class Foo(val a, val b)
 //│       (nop)
 //│       (block (result (ref null any))
 //│         (local.set $tmp
-//│           (call $Foo
+//│           (call $Foo_ctor
 //│             (ref.i31
 //│               (i32.const 42))
 //│             (ref.i31
diff --git a/hkmc2/shared/src/test/mlscript/wasm/SingletonUnit.mls b/hkmc2/shared/src/test/mlscript/wasm/SingletonUnit.mls
index b4ed1cf248..d9d83ef401 100644
--- a/hkmc2/shared/src/test/mlscript/wasm/SingletonUnit.mls
+++ b/hkmc2/shared/src/test/mlscript/wasm/SingletonUnit.mls
@@ -12,8 +12,8 @@
 //│   (type $entry1 (func (result (ref null any))))
 //│   (type $start (func))
 //│   (global $Unit$inst (mut (ref null $Unit)) (ref.null $Unit))
-//│   (start 1)
-//│   (func  (type $Unit_ctor) (result (ref null any))
+//│   (start $start1)
+//│   (func $Unit_ctor1 (type $Unit_ctor) (result (ref null any))
 //│     (local $this (ref null any))
 //│     (block (result (ref null any))
 //│       (local.set $this
@@ -25,11 +25,13 @@
 //│       (nop)
 //│       (return
 //│         (local.get $this))))
-//│   (func  (type $start)
+//│   (elem declare func $Unit_ctor1)
+//│   (func $start1 (type $start)
 //│     (block
 //│       (global.set $Unit$inst
 //│         (ref.cast (ref null $Unit)
 //│           (call 0)))))
+//│   (elem declare func $start1)
 //│   (func $entry (type $entry1) (result (ref null any))
 //│     (global.get $Unit$inst))
 //│   (export "entry" (func $entry))
diff --git a/hkmc2/shared/src/test/mlscript/wasm/Singletons.mls b/hkmc2/shared/src/test/mlscript/wasm/Singletons.mls
index d0459ea7f7..11e04a462e 100644
--- a/hkmc2/shared/src/test/mlscript/wasm/Singletons.mls
+++ b/hkmc2/shared/src/test/mlscript/wasm/Singletons.mls
@@ -20,8 +20,8 @@ Bar.y
 //│   (type $start (func))
 //│   (global $Foo$inst (mut (ref null $Foo)) (ref.null $Foo))
 //│   (global $Bar$inst (mut (ref null $Bar)) (ref.null $Bar))
-//│   (start 2)
-//│   (func  (type $Foo_ctor) (result (ref null any))
+//│   (start $start1)
+//│   (func $Foo_ctor1 (type $Foo_ctor) (result (ref null any))
 //│     (local $this (ref null any))
 //│     (block (result (ref null any))
 //│       (local.set $this
@@ -39,7 +39,8 @@ Bar.y
 //│         (nop))
 //│       (return
 //│         (local.get $this))))
-//│   (func  (type $Bar_ctor) (result (ref null any))
+//│   (elem declare func $Foo_ctor1)
+//│   (func $Bar_ctor1 (type $Bar_ctor) (result (ref null any))
 //│     (local $this (ref null any))
 //│     (block (result (ref null any))
 //│       (local.set $this
@@ -57,7 +58,8 @@ Bar.y
 //│         (nop))
 //│       (return
 //│         (local.get $this))))
-//│   (func  (type $start)
+//│   (elem declare func $Bar_ctor1)
+//│   (func $start1 (type $start)
 //│     (block
 //│       (global.set $Foo$inst
 //│         (ref.cast (ref null $Foo)
@@ -65,6 +67,7 @@ Bar.y
 //│       (global.set $Bar$inst
 //│         (ref.cast (ref null $Bar)
 //│           (call 1)))))
+//│   (elem declare func $start1)
 //│   (func $entry (type $entry1) (result (ref null any))
 //│     (local $Bar (ref null any))
 //│     (local $Foo (ref null any))

From 54dcfdf0c6bbc397b7d7e0895fd84c13be64dda3 Mon Sep 17 00:00:00 2001
From: David Mak <david.18.19.21@gmail.com>
Date: Sat, 14 Mar 2026 01:10:16 +0800
Subject: [PATCH 07/16] wasm: Emit `$$tag` instead of `FieldIdx(0)`

---
 .../src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala | 2 +-
 hkmc2/shared/src/test/mlscript/wasm/Basics.mls              | 6 +++---
 hkmc2/shared/src/test/mlscript/wasm/ControlFlow.mls         | 2 +-
 hkmc2/shared/src/test/mlscript/wasm/Matching.mls            | 4 ++--
 hkmc2/shared/src/test/mlscript/wasm/ScopedLocals.mls        | 2 +-
 hkmc2/shared/src/test/mlscript/wasm/SingletonUnit.mls       | 2 +-
 hkmc2/shared/src/test/mlscript/wasm/Singletons.mls          | 4 ++--
 7 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala
index 22fe140438..e5e8672160 100644
--- a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala
+++ b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala
@@ -1100,7 +1100,7 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
                       Seq(
                         local.set(thisVar, struct.new_default(typeref)),
                         struct.set(
-                          FieldIdx(NumIdx(0)),
+                          FieldIdx(ctx.getTypeInfo_!(typeref).compType.asInstanceOf[StructType].fields(0)._2.id),
                           ref.cast(
                             local.get(thisVar, RefType.anyref),
                             RefType(typeref, nullable = false),
diff --git a/hkmc2/shared/src/test/mlscript/wasm/Basics.mls b/hkmc2/shared/src/test/mlscript/wasm/Basics.mls
index f859d76b9b..996f6c2304 100644
--- a/hkmc2/shared/src/test/mlscript/wasm/Basics.mls
+++ b/hkmc2/shared/src/test/mlscript/wasm/Basics.mls
@@ -126,7 +126,7 @@ class Foo(val a)
 //│     (block (result (ref null any))
 //│       (local.set $this
 //│         (struct.new_default $Foo))
-//│       (struct.set $Foo 0
+//│       (struct.set $Foo $$tag
 //│         (ref.cast (ref $Foo)
 //│           (local.get $this))
 //│         (i32.const 1))
@@ -180,7 +180,7 @@ class Foo(val x) with
 //│     (block (result (ref null any))
 //│       (local.set $this
 //│         (struct.new_default $Foo))
-//│       (struct.set $Foo 0
+//│       (struct.set $Foo $$tag
 //│         (ref.cast (ref $Foo)
 //│           (local.get $this))
 //│         (i32.const 1))
@@ -239,7 +239,7 @@ O.y
 //│     (block (result (ref null any))
 //│       (local.set $this
 //│         (struct.new_default $O))
-//│       (struct.set $O 0
+//│       (struct.set $O $$tag
 //│         (ref.cast (ref $O)
 //│           (local.get $this))
 //│         (i32.const 1))
diff --git a/hkmc2/shared/src/test/mlscript/wasm/ControlFlow.mls b/hkmc2/shared/src/test/mlscript/wasm/ControlFlow.mls
index 5256d15409..0a4eff4e26 100644
--- a/hkmc2/shared/src/test/mlscript/wasm/ControlFlow.mls
+++ b/hkmc2/shared/src/test/mlscript/wasm/ControlFlow.mls
@@ -61,7 +61,7 @@ let i = 0 in
 //│     (block (result (ref null any))
 //│       (local.set $this
 //│         (struct.new_default $Unit))
-//│       (struct.set $Unit 0
+//│       (struct.set $Unit $$tag
 //│         (ref.cast (ref $Unit)
 //│           (local.get $this))
 //│         (i32.const 3))
diff --git a/hkmc2/shared/src/test/mlscript/wasm/Matching.mls b/hkmc2/shared/src/test/mlscript/wasm/Matching.mls
index ee364b6293..991291323a 100644
--- a/hkmc2/shared/src/test/mlscript/wasm/Matching.mls
+++ b/hkmc2/shared/src/test/mlscript/wasm/Matching.mls
@@ -54,7 +54,7 @@ if Bar(true) is
 //│     (block (result (ref null any))
 //│       (local.set $this
 //│         (struct.new_default $Bar))
-//│       (struct.set $Bar 0
+//│       (struct.set $Bar $$tag
 //│         (ref.cast (ref $Bar)
 //│           (local.get $this))
 //│         (i32.const 1))
@@ -73,7 +73,7 @@ if Bar(true) is
 //│     (block (result (ref null any))
 //│       (local.set $this
 //│         (struct.new_default $Baz))
-//│       (struct.set $Baz 0
+//│       (struct.set $Baz $$tag
 //│         (ref.cast (ref $Baz)
 //│           (local.get $this))
 //│         (i32.const 2))
diff --git a/hkmc2/shared/src/test/mlscript/wasm/ScopedLocals.mls b/hkmc2/shared/src/test/mlscript/wasm/ScopedLocals.mls
index 113985457a..20f3f17a67 100644
--- a/hkmc2/shared/src/test/mlscript/wasm/ScopedLocals.mls
+++ b/hkmc2/shared/src/test/mlscript/wasm/ScopedLocals.mls
@@ -178,7 +178,7 @@ class Foo(val a, val b)
 //│     (block (result (ref null any))
 //│       (local.set $this
 //│         (struct.new_default $Foo))
-//│       (struct.set $Foo 0
+//│       (struct.set $Foo $$tag
 //│         (ref.cast (ref $Foo)
 //│           (local.get $this))
 //│         (i32.const 1))
diff --git a/hkmc2/shared/src/test/mlscript/wasm/SingletonUnit.mls b/hkmc2/shared/src/test/mlscript/wasm/SingletonUnit.mls
index d9d83ef401..b8241c5640 100644
--- a/hkmc2/shared/src/test/mlscript/wasm/SingletonUnit.mls
+++ b/hkmc2/shared/src/test/mlscript/wasm/SingletonUnit.mls
@@ -18,7 +18,7 @@
 //│     (block (result (ref null any))
 //│       (local.set $this
 //│         (struct.new_default $Unit))
-//│       (struct.set $Unit 0
+//│       (struct.set $Unit $$tag
 //│         (ref.cast (ref $Unit)
 //│           (local.get $this))
 //│         (i32.const 1))
diff --git a/hkmc2/shared/src/test/mlscript/wasm/Singletons.mls b/hkmc2/shared/src/test/mlscript/wasm/Singletons.mls
index 11e04a462e..451da0c018 100644
--- a/hkmc2/shared/src/test/mlscript/wasm/Singletons.mls
+++ b/hkmc2/shared/src/test/mlscript/wasm/Singletons.mls
@@ -26,7 +26,7 @@ Bar.y
 //│     (block (result (ref null any))
 //│       (local.set $this
 //│         (struct.new_default $Foo))
-//│       (struct.set $Foo 0
+//│       (struct.set $Foo $$tag
 //│         (ref.cast (ref $Foo)
 //│           (local.get $this))
 //│         (i32.const 1))
@@ -45,7 +45,7 @@ Bar.y
 //│     (block (result (ref null any))
 //│       (local.set $this
 //│         (struct.new_default $Bar))
-//│       (struct.set $Bar 0
+//│       (struct.set $Bar $$tag
 //│         (ref.cast (ref $Bar)
 //│           (local.get $this))
 //│         (i32.const 2))

From 7dfdf6ef9cfbcd504ad4b9c377cc88148850abde Mon Sep 17 00:00:00 2001
From: David Mak <david.18.19.21@gmail.com>
Date: Sat, 14 Mar 2026 16:32:22 +0800
Subject: [PATCH 08/16] wasm: Make symbolic index for function imports
 mandatory

---
 .../shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala | 2 +-
 .../src/main/scala/hkmc2/codegen/wasm/text/Wasm.scala       | 6 ++----
 .../src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala | 2 +-
 3 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala
index 5524c4ac6e..084955c029 100644
--- a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala
+++ b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala
@@ -374,7 +374,7 @@ class Ctx(
     functionImports += funcImport
     sym.foreach:
       namedFuncs(_) = numIdx
-    FuncIdx(funcImport.id.getOrElse(NumIdx(numIdx)))
+    FuncIdx(funcImport.id)
 
   /** Returns the cached function import for (`module`, `name`), creating it with `createImport` if needed.
     */
diff --git a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Wasm.scala b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Wasm.scala
index cc291d85b7..5bef9f69c4 100644
--- a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Wasm.scala
+++ b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Wasm.scala
@@ -196,11 +196,9 @@ case class MemoryImport(module: Str, name: Str, minPages: Int) extends ToWat:
     doc"""(import "$module" "$name" (memory $minPages))"""
 
 /** A function import entry. */
-case class FuncImport(module: Str, name: Str, id: Opt[SymIdx], typeIdx: TypeIdx) extends ToWat:
+case class FuncImport(module: Str, name: Str, id: SymIdx, typeIdx: TypeIdx) extends ToWat:
   def toWat: Document =
-    doc"""(import "$module" "$name" (func ${
-        id.fold(doc"")(_.toWat)
-      } (type ${typeIdx.toWat})))"""
+    doc"""(import "$module" "$name" (func ${id.toWat} (type ${typeIdx.toWat})))"""
 
 /** A data segment entry. */
 case class DataSegment(offsetExpr: Expr, bytes: Str) extends ToWat:
diff --git a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala
index e5e8672160..e7262aec97 100644
--- a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala
+++ b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala
@@ -259,7 +259,7 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
       FuncImport(
         module = ExternIntrinsics.SystemModule,
         name = ExternIntrinsics.StringFromUtf16ImportName,
-        id = S(SymIdx(ExternIntrinsics.StringFromUtf16ImportName)),
+        id = SymIdx(ExternIntrinsics.StringFromUtf16ImportName),
         typeIdx = importTy,
       )
   end getOrLoadStrCtorFunction

From 17b4f56585c2bea82dbec485ee2725af14aca88c Mon Sep 17 00:00:00 2001
From: David Mak <david.18.19.21@gmail.com>
Date: Sat, 14 Mar 2026 16:43:10 +0800
Subject: [PATCH 09/16] wasm: Name imported memory

---
 .../src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala   | 10 +++++++++-
 .../src/main/scala/hkmc2/codegen/wasm/text/Wasm.scala  |  4 ++--
 .../scala/hkmc2/codegen/wasm/text/WatBuilder.scala     |  2 +-
 hkmc2/shared/src/test/mlscript/wasm/Strings.mls        |  2 +-
 4 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala
index 084955c029..ffba772d01 100644
--- a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala
+++ b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala
@@ -12,6 +12,7 @@ import semantics.*, Elaborator.State
 import text.Param as WasmParam
 import Instructions.*
 
+import scala.annotation.nowarn
 import scala.collection.mutable.{ArrayBuffer as ArrayBuf, Map as MutMap}
 
 /** A Wasm function and its associated information.
@@ -344,6 +345,7 @@ class Ctx(
       lastWords(s"Missing type definition for ${typeref.prettyString}")
 
   /** Returns the [[TypeInfo]] instance associated with the given `typeref`. */
+  @nowarn("cat=deprecation")
   def getTypeInfo(typeref: TypeIdx | BlockMemberSymbol): Opt[TypeInfo] = typeref match
     case TypeIdx(NumIdx(idx)) => types.unapply(idx.toInt)
     case TypeIdx(SymIdx(nme)) =>
@@ -397,13 +399,18 @@ class Ctx(
           memoryImports(idx) = existing.copy(minPages = newMin)
       case N =>
         val idx = memoryImports.size
-        memoryImports += MemoryImport(module, name, minPages)
+        memoryImports += MemoryImport(module, name, SymIdx(name), minPages)
         cachedMemoryImport(key) = idx
 
   /** Returns the minimum page requirement of memory import (`module`, `name`) if present. */
+  @deprecated("Use `getMemoryImport` instead to get the full `MemoryImport` information.")
   def getMemoryImportMinPages(module: Str, name: Str): Opt[Int] =
     memoryImports.find(m => m.module === module && m.name === name).map(_.minPages)
 
+  /** Returns the memory import information for the given (`module`, `name`) tuple if present. */
+  def getMemoryImport(module: Str, name: Str): Opt[MemoryImport] =
+    memoryImports.find(m => m.module === module && m.name === name)
+
   /** Adds a data segment into this context. */
   def addDataSegment(seg: DataSegment): Unit =
     dataSegments += seg
@@ -440,6 +447,7 @@ class Ctx(
       lastWords(s"Missing function definition for ${funcref.prettyString}")
 
   /** Returns the [[FuncInfo]] instance associated with the given `funcref`. */
+  @nowarn("cat=deprecation")
   def getFuncInfo(funcref: FuncIdx | Symbol): Opt[FuncInfo] = funcref match
     case FuncIdx(NumIdx(idx)) =>
       funcInfosByIndex.get(idx).orElse:
diff --git a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Wasm.scala b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Wasm.scala
index 5bef9f69c4..b9290f8145 100644
--- a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Wasm.scala
+++ b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Wasm.scala
@@ -191,9 +191,9 @@ case class FieldIdx(idx: Index) extends CtxIdx(idx)
 case class TagIdx(idx: Index) extends CtxIdx(idx)
 
 /** A memory import entry. */
-case class MemoryImport(module: Str, name: Str, minPages: Int) extends ToWat:
+case class MemoryImport(module: Str, name: Str, id: SymIdx, minPages: Int) extends ToWat:
   def toWat: Document =
-    doc"""(import "$module" "$name" (memory $minPages))"""
+    doc"""(import "$module" "$name" (memory ${id.toWat} $minPages))"""
 
 /** A function import entry. */
 case class FuncImport(module: Str, name: Str, id: SymIdx, typeIdx: TypeIdx) extends ToWat:
diff --git a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala
index e7262aec97..0f4dd3bcce 100644
--- a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala
+++ b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala
@@ -1574,7 +1574,7 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
     ctx.addFunc(S(entrySym), entryFnInfo)
 
     val systemMemMinPages =
-      ctx.getMemoryImportMinPages(ExternIntrinsics.SystemModule, ExternIntrinsics.SystemMemoryImportName).getOrElse(0)
+      ctx.getMemoryImport(ExternIntrinsics.SystemModule, ExternIntrinsics.SystemMemoryImportName).fold(0)(_.minPages)
     (ctx.toWat, entryNme, systemMemMinPages)
   end program
 
diff --git a/hkmc2/shared/src/test/mlscript/wasm/Strings.mls b/hkmc2/shared/src/test/mlscript/wasm/Strings.mls
index d3620df5bb..768c650564 100644
--- a/hkmc2/shared/src/test/mlscript/wasm/Strings.mls
+++ b/hkmc2/shared/src/test/mlscript/wasm/Strings.mls
@@ -21,7 +21,7 @@ let dup2 = "dup"
 //│   (type $TupleArray (array (ref null any)))
 //│   (type $TupleArrayMut (array (mut (ref null any))))
 //│   (type $entry1 (func (result (ref null any))))
-//│   (import "system" "mem" (memory 1))
+//│   (import "system" "mem" (memory $mem 1))
 //│   (import "system" "mlx_str_from_utf16" (func $mlx_str_from_utf16 (type $mlx_str_from_utf16)))
 //│   (data (i32.const 0) "\64\00\75\00\70\00")
 //│   (func $entry (type $entry1) (result (ref null any))

From ed07049231b8ffbbd9b6ee080bc743fe48e5a3b3 Mon Sep 17 00:00:00 2001
From: David Mak <david.18.19.21@gmail.com>
Date: Sat, 14 Mar 2026 17:18:28 +0800
Subject: [PATCH 10/16] wasm: Use symbolic index for constructor invocation

---
 .../src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala   | 2 +-
 hkmc2/shared/src/test/mlscript/wasm/Basics.mls                | 2 +-
 hkmc2/shared/src/test/mlscript/wasm/ControlFlow.mls           | 2 +-
 hkmc2/shared/src/test/mlscript/wasm/SingletonUnit.mls         | 2 +-
 hkmc2/shared/src/test/mlscript/wasm/Singletons.mls            | 4 ++--
 5 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala
index 0f4dd3bcce..5df299f29f 100644
--- a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala
+++ b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala
@@ -136,7 +136,7 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
     )
 
     val ctorCall = call(
-      funcidx = ctx.getFunc_!(clsLikeDefn.sym, resolveSymIdx = true),
+      funcidx = ctx.getFunc_!(clsLikeDefn.sym),
       operands = Seq.empty,
       returnTypes = Seq(Result(RefType.anyref)),
     )
diff --git a/hkmc2/shared/src/test/mlscript/wasm/Basics.mls b/hkmc2/shared/src/test/mlscript/wasm/Basics.mls
index 996f6c2304..080f8d0469 100644
--- a/hkmc2/shared/src/test/mlscript/wasm/Basics.mls
+++ b/hkmc2/shared/src/test/mlscript/wasm/Basics.mls
@@ -264,7 +264,7 @@ O.y
 //│     (block
 //│       (global.set $O$inst
 //│         (ref.cast (ref null $O)
-//│           (call 0)))))
+//│           (call $O_ctor1)))))
 //│   (elem declare func $start1)
 //│   (func $entry (type $entry1) (result (ref null any))
 //│     (local $O (ref null any))
diff --git a/hkmc2/shared/src/test/mlscript/wasm/ControlFlow.mls b/hkmc2/shared/src/test/mlscript/wasm/ControlFlow.mls
index 0a4eff4e26..5ccab493d6 100644
--- a/hkmc2/shared/src/test/mlscript/wasm/ControlFlow.mls
+++ b/hkmc2/shared/src/test/mlscript/wasm/ControlFlow.mls
@@ -73,7 +73,7 @@ let i = 0 in
 //│     (block
 //│       (global.set $Unit$inst
 //│         (ref.cast (ref null $Unit)
-//│           (call 2)))))
+//│           (call $Unit_ctor1)))))
 //│   (elem declare func $start1)
 //│   (func $entry (type $entry1) (result (ref null any))
 //│     (local $i (ref null any))
diff --git a/hkmc2/shared/src/test/mlscript/wasm/SingletonUnit.mls b/hkmc2/shared/src/test/mlscript/wasm/SingletonUnit.mls
index b8241c5640..df849c91bb 100644
--- a/hkmc2/shared/src/test/mlscript/wasm/SingletonUnit.mls
+++ b/hkmc2/shared/src/test/mlscript/wasm/SingletonUnit.mls
@@ -30,7 +30,7 @@
 //│     (block
 //│       (global.set $Unit$inst
 //│         (ref.cast (ref null $Unit)
-//│           (call 0)))))
+//│           (call $Unit_ctor1)))))
 //│   (elem declare func $start1)
 //│   (func $entry (type $entry1) (result (ref null any))
 //│     (global.get $Unit$inst))
diff --git a/hkmc2/shared/src/test/mlscript/wasm/Singletons.mls b/hkmc2/shared/src/test/mlscript/wasm/Singletons.mls
index 451da0c018..a072393320 100644
--- a/hkmc2/shared/src/test/mlscript/wasm/Singletons.mls
+++ b/hkmc2/shared/src/test/mlscript/wasm/Singletons.mls
@@ -63,10 +63,10 @@ Bar.y
 //│     (block
 //│       (global.set $Foo$inst
 //│         (ref.cast (ref null $Foo)
-//│           (call 0)))
+//│           (call $Foo_ctor1)))
 //│       (global.set $Bar$inst
 //│         (ref.cast (ref null $Bar)
-//│           (call 1)))))
+//│           (call $Bar_ctor1)))))
 //│   (elem declare func $start1)
 //│   (func $entry (type $entry1) (result (ref null any))
 //│     (local $Bar (ref null any))

From 778b6bae81e2a0385e849d6b72f6d6b8e4573ae0 Mon Sep 17 00:00:00 2001
From: David Mak <david.18.19.21@gmail.com>
Date: Sat, 14 Mar 2026 17:20:03 +0800
Subject: [PATCH 11/16] wasm: Use monotonically increasing counter for object
 tags

---
 .../scala/hkmc2/codegen/wasm/text/Ctx.scala   | 18 ++++++++--
 .../hkmc2/codegen/wasm/text/WatBuilder.scala  | 35 ++++++++++++-------
 .../src/test/mlscript/wasm/ControlFlow.mls    |  2 +-
 .../src/test/mlscript/wasm/Matching.mls       |  4 +--
 4 files changed, 41 insertions(+), 18 deletions(-)

diff --git a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala
index ffba772d01..59cc596013 100644
--- a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala
+++ b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala
@@ -148,22 +148,25 @@ end GlobalInfo
   *   Symbolic identifier for the function, or `N` if the function is anonymous.
   * @param compType
   *   The composite type this type definition represents.
+  * @param objectTag
+  *   An optional object tag number associated with this type.
   */
-class TypeInfo(val id: SymIdx, val compType: CompType) extends ToWat:
+class TypeInfo(val id: SymIdx, val compType: CompType, val objectTag: Opt[Int]) extends ToWat:
 
   /** @param sym
     *   The source [[BlockMemberSymbol]] which this type is generated from.
     * @param compType
     *   The composite type this type definition represents.
     */
-  def this(sym: BlockMemberSymbol, compType: CompType)(using Raise, Scope) = this(
+  def this(sym: BlockMemberSymbol, compType: CompType, objectTag: Opt[Int])(using Raise, Scope) = this(
     SymIdx(sym.optionIf(_.nameIsMeaningful).fold(summon[Scope].allocateName(sym))(_.nme)),
     compType,
+    objectTag,
   )
 
   @deprecated("Consider providing a symbolic identifier by using `Scope.allocateName` with a `TempSymbol`.")
   def this(id: Opt[SymIdx], compType: CompType)(using Raise, Scope, State) =
-    this(id.getOrElse(SymIdx(summon[Scope].allocateName(TempSymbol(N, "")))), compType)
+    this(id.getOrElse(SymIdx(summon[Scope].allocateName(TempSymbol(N, "")))), compType, N)
 
   def toWat: Document = compType match
     case struct: StructType if struct.isSubtype =>
@@ -286,6 +289,9 @@ class Ctx(
 
   import Ctx.prettyString
 
+  /** Monotonically increasing counter for generating object tags. */
+  private var objectTagNum = 0
+
   private val wasmIntrinsicFuncs: MutMap[Str, FuncIdx] = MutMap.empty
   private val wasmIntrinsicTypes: MutMap[WasmIntrinsicType, TypeIdx] = MutMap.empty
   private val wasmIntrinsicTags: MutMap[Str, TagIdx] = MutMap.empty
@@ -310,6 +316,12 @@ class Ctx(
     labelTargets.collectFirst:
       case (sym, target) if sym eq label => target
 
+  /** Returns a new number to be used as an object tag. */
+  def getFreshObjectTag(): Int =
+    val tag = objectTagNum
+    objectTagNum += 1
+    tag ensuring objectTagNum > tag
+
   /** Adds a type into this context. */
   def addType(sym: Opt[BlockMemberSymbol], typeInfo: TypeInfo): TypeIdx =
     val numIdx = types.size
diff --git a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala
index 5df299f29f..e6b6874742 100644
--- a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala
+++ b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala
@@ -162,6 +162,7 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
           typeInfo = TypeInfo(
             sym = defn.sym,
             compType = StructType(fields = allFields, parents = Seq(baseObjectTypeIdx), isSubtype = true),
+            objectTag = S(ctx.getFreshObjectTag()),
           ),
         )
       end if
@@ -203,6 +204,7 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
           TypeInfo(
             id = SymIdx(symNme),
             FunctionType(params = Seq(WasmParam(N, RefType.anyref)), results = Seq.empty),
+            objectTag = S(ctx.getFreshObjectTag()),
           ),
         ),
       )),
@@ -254,6 +256,7 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
             params = Seq(WasmParam(N, RefType.anyref), WasmParam(N, RefType.anyref)),
             results = Seq(Result(RefType.anyref)),
           ),
+          objectTag = N,
         ),
       )
       FuncImport(
@@ -275,6 +278,7 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
         TypeInfo(
           sym,
           ArrayType(elemType = RefType.anyref, mutable = mut),
+          objectTag = N,
         ),
       )
 
@@ -783,6 +787,7 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
           params = params.map((_, nme) => WasmParam(S(nme), RefType.anyref)),
           results = Seq(Result(RefType.anyref)),
         ),
+        objectTag = N,
       ),
     )
     val funcInfo = FuncInfo(
@@ -1022,6 +1027,7 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
                             params = params.map(_._1),
                             results = Seq.fill(bodyWat.resultTypes.length)(Result(RefType.anyref)),
                           ),
+                          objectTag = N,
                         ),
                       )
 
@@ -1081,6 +1087,7 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
                     // Use the symbolic type reference (e.g. `$Foo`) in emitted WAT for readability.
                     // Numeric indices are only needed for `$tag` values.
                     val typeref = ctx.getType_!(clsLikeDefn.sym)
+                    val typeinfo = ctx.getTypeInfo_!(typeref)
 
                     val (ctorParams, thisVar, ctorWat, ctorLocals) = setupCtorLocals(clsLikeDefn)
 
@@ -1091,16 +1098,15 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
                           case Nil => (ctorAuxParams, Nil)
                       case Some(_) => (ctorAuxParams, ctorParams)
 
-                    val tagValue = ctx.getType_!(clsLikeDefn.sym, resolveSymIdx = true) match
-                      case TypeIdx(NumIdx(idx)) => idx
-                      case _ => lastWords(s"Expected numeric type index for class ${clsLikeDefn.sym}")
+                    val tagValue = typeinfo.objectTag.getOrElse:
+                      lastWords(s"Expected class ${clsLikeDefn.sym} to have an object tag")
 
                     val ctorCode = blockInstr(
                       label = N,
                       Seq(
                         local.set(thisVar, struct.new_default(typeref)),
                         struct.set(
-                          FieldIdx(ctx.getTypeInfo_!(typeref).compType.asInstanceOf[StructType].fields(0)._2.id),
+                          FieldIdx(typeinfo.compType.asInstanceOf[StructType].fields(0)._2.id),
                           ref.cast(
                             local.get(thisVar, RefType.anyref),
                             RefType(typeref, nullable = false),
@@ -1133,6 +1139,7 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
                           params = ctorParams.map(p => WasmParam(S(p._2), RefType.anyref)),
                           results = Seq(Result(RefType.anyref)),
                         ),
+                        objectTag = N,
                       ),
                     )
 
@@ -1342,14 +1349,11 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
                     Ls(msg"Could not resolve BlockMemberSymbol for class pattern" -> cls.toLoc),
                     extraInfo = S(s"ClassLikeSymbol: ${cls.toString}"),
                   ))
-                val clsTypeIdx = ctx.getType_!(clsBlkMemberSym, resolveSymIdx = true)
+                val clsTypeIdx = ctx.getType_!(clsBlkMemberSym)
+                val typeinfo = ctx.getTypeInfo_!(clsTypeIdx)
 
-                val expectedTag = clsTypeIdx match
-                  case TypeIdx(NumIdx(idx)) => idx
-                  case _ => break(errExpr(
-                      Ls(msg"Expected numeric type index for class pattern" -> cls.toLoc),
-                      extraInfo = S(s"TypeIdx: ${clsTypeIdx}"),
-                    ))
+                val expectedTag = typeinfo.objectTag.getOrElse:
+                  lastWords(s"Expected class $clsBlkMemberSym to have an object tag")
 
                 val scrutExpr = getScrutExpr
                 val isStructCompatible = ref.test(scrutExpr, baseObjectRefType(nullable = true))
@@ -1361,7 +1365,11 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
 
                 // Safe to cast and extract tag since ref.test passed
                 val scrutAsObject = ref.cast(scrutExpr, baseObjectRefType(nullable = false))
-                val scrutTag = struct.get(FieldIdx(NumIdx(0)), scrutAsObject, I32Type)
+                val scrutTag = struct.get(
+                  FieldIdx(typeinfo.compType.asInstanceOf[StructType].fields(0)._2.id),
+                  scrutAsObject,
+                  I32Type,
+                )
                 val tagMatches = i32.eq(scrutTag, i32.const(expectedTag))
 
                 S(`if`(
@@ -1501,6 +1509,7 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
           Seq(tagFieldSym -> Field(I32Type, mutable = true, id = SymIdx("$tag"))),
           isSubtype = true,
         ),
+        objectTag = S(ctx.getFreshObjectTag() ensuring (_ == 0)),
       ),
     )
 
@@ -1523,6 +1532,7 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
       TypeInfo(
         id = SymIdx(scope.allocateName(TempSymbol(N, entryNme))),
         FunctionType(params = Seq.empty, results = Seq(Result(RefType.anyref))),
+        objectTag = N,
       ),
     )
     val entryFnInfo = FuncInfo(
@@ -1549,6 +1559,7 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
         TypeInfo(
           id = SymIdx(scope.allocateName(TempSymbol(N, "start"))),
           FunctionType(params = Seq.empty, results = Seq.empty),
+          objectTag = N,
         ),
       )
       val initBody = blockInstr(
diff --git a/hkmc2/shared/src/test/mlscript/wasm/ControlFlow.mls b/hkmc2/shared/src/test/mlscript/wasm/ControlFlow.mls
index 5ccab493d6..049866facb 100644
--- a/hkmc2/shared/src/test/mlscript/wasm/ControlFlow.mls
+++ b/hkmc2/shared/src/test/mlscript/wasm/ControlFlow.mls
@@ -64,7 +64,7 @@ let i = 0 in
 //│       (struct.set $Unit $$tag
 //│         (ref.cast (ref $Unit)
 //│           (local.get $this))
-//│         (i32.const 3))
+//│         (i32.const 1))
 //│       (nop)
 //│       (return
 //│         (local.get $this))))
diff --git a/hkmc2/shared/src/test/mlscript/wasm/Matching.mls b/hkmc2/shared/src/test/mlscript/wasm/Matching.mls
index 991291323a..d784485989 100644
--- a/hkmc2/shared/src/test/mlscript/wasm/Matching.mls
+++ b/hkmc2/shared/src/test/mlscript/wasm/Matching.mls
@@ -117,7 +117,7 @@ if Bar(true) is
 //│                 (then
 //│                   (if
 //│                     (i32.eq
-//│                       (struct.get $Object 0
+//│                       (struct.get $Object $$tag
 //│                         (ref.cast (ref $Object)
 //│                           (local.get $scrut)))
 //│                       (i32.const 1))
@@ -159,7 +159,7 @@ if Bar(true) is
 //│                 (then
 //│                   (if
 //│                     (i32.eq
-//│                       (struct.get $Object 0
+//│                       (struct.get $Object $$tag
 //│                         (ref.cast (ref $Object)
 //│                           (local.get $scrut)))
 //│                       (i32.const 2))

From 0d69b6e64a4824fc8494b2dd7ac0c04a3e4d843c Mon Sep 17 00:00:00 2001
From: David Mak <david.18.19.21@gmail.com>
Date: Sat, 14 Mar 2026 18:19:02 +0800
Subject: [PATCH 12/16] wasm: Use `Opt[Str]` for function exports

We don't need multiple exports for now.
---
 .../scala/hkmc2/codegen/wasm/text/Ctx.scala     | 17 +++++++----------
 .../hkmc2/codegen/wasm/text/WatBuilder.scala    |  8 ++++----
 2 files changed, 11 insertions(+), 14 deletions(-)

diff --git a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala
index 59cc596013..53c97860e6 100644
--- a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala
+++ b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala
@@ -32,7 +32,7 @@ import scala.collection.mutable.{ArrayBuffer as ArrayBuf, Map as MutMap}
   * @param body
   *   The expression of the function body.
   * @param exports
-  *   [[Seq]] of export names for the function.
+  *   Optional export name for the function.
   */
 class FuncInfo(
     val id: SymIdx,
@@ -41,7 +41,7 @@ class FuncInfo(
     nResults: Int,
     locals: Seq[Local -> Str],
     val body: Expr,
-    val exports: Seq[Str],
+    val `export`: Opt[Str],
 ) extends ToWat:
 
   /** @param sym
@@ -71,7 +71,7 @@ class FuncInfo(
     nResults,
     locals,
     body,
-    sym.optionIf(_.nameIsMeaningful).map(_.nme).toSeq,
+    sym.optionIf(_.nameIsMeaningful).map(_.nme),
   )
 
   @deprecated("Consider providing a symbolic identifier by using `Scope.allocateName` with a `TempSymbol`.")
@@ -82,7 +82,7 @@ class FuncInfo(
       nResults: Int,
       locals: Seq[Local -> Str],
       body: Expr,
-      exports: Seq[Str],
+      `export`: Opt[Str],
   )(using Raise, Scope, State) = this(
     id.getOrElse(SymIdx(summon[Scope].allocateName(TempSymbol(N, "")))),
     typeIdx,
@@ -90,7 +90,7 @@ class FuncInfo(
     nResults,
     locals,
     body,
-    exports,
+    `export`,
   )
 
   /** Returns the type of this function as a [[SignatureType]]. */
@@ -100,7 +100,6 @@ class FuncInfo(
   )
 
   def toWat: Document =
-    // TODO(Derppening): Make exports configurable
     doc"""(func ${id.toWat} (type ${typeIdx.toWat})${
         getSignatureType.toWat.surroundUnlessEmpty(doc" ")
       } #{ ${
@@ -108,10 +107,8 @@ class FuncInfo(
           doc"(local $$${p._2} ${RefType.anyref.toWat})"
         .mkDocument(doc" # ").surroundUnlessEmpty(doc" # ")
       } # ${body.toWat} #} )${
-        exports
-          .map: e =>
-            doc""" # (export "${e}" (func ${id.toWat}))"""
-          .mkDocument(doc"")
+        `export`.fold(doc""): e =>
+          doc""" # (export "${e}" (func ${id.toWat}))"""
       } # (elem declare func ${id.toWat})"""
 end FuncInfo
 
diff --git a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala
index e6b6874742..1ee1ce4dc5 100644
--- a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala
+++ b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/WatBuilder.scala
@@ -797,7 +797,7 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
       nResults = 1,
       locals = Seq.empty,
       body = body,
-      exports = Seq.empty,
+      `export` = N,
     )
     ctx.addFunc(N, funcInfo)
   end createIntrinsicFunc
@@ -1158,7 +1158,7 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
                         nResults = ctorCode.resultTypes.length,
                         locals = ctorLocals,
                         body = ctorAux,
-                        exports = ctorId.toSeq,
+                        `export` = ctorId,
                       ),
                     )
                     if isSingletonObj then
@@ -1543,7 +1543,7 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
       // TODO(Derppening): Should we place top-level scope variables in the global section?
       locals = (entryFnLocals ++ entryExtraLocals).map(l => l -> scope.allocateOrGetName(l)),
       body = entryFnExpr,
-      exports = Seq(entryNme),
+      `export` = S(entryNme),
     )
 
     ctx.popLocal()
@@ -1576,7 +1576,7 @@ class WatBuilder(using TraceLogger, State) extends CodeBuilder:
           nResults = 0,
           locals = Seq.empty,
           body = initBody,
-          exports = Seq.empty,
+          `export` = N,
         ),
       )
       ctx.setStartFunc(initFn)

From d0950a37ca65adce401c9f9e489375ac1e78064c Mon Sep 17 00:00:00 2001
From: David Mak <david.18.19.21@gmail.com>
Date: Sat, 14 Mar 2026 18:19:41 +0800
Subject: [PATCH 13/16] Remove deprecation for `TypeInfo` constructor with
 optional ID

---
 hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala | 1 -
 1 file changed, 1 deletion(-)

diff --git a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala
index 53c97860e6..2395ab5cc9 100644
--- a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala
+++ b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala
@@ -161,7 +161,6 @@ class TypeInfo(val id: SymIdx, val compType: CompType, val objectTag: Opt[Int])
     objectTag,
   )
 
-  @deprecated("Consider providing a symbolic identifier by using `Scope.allocateName` with a `TempSymbol`.")
   def this(id: Opt[SymIdx], compType: CompType)(using Raise, Scope, State) =
     this(id.getOrElse(SymIdx(summon[Scope].allocateName(TempSymbol(N, "")))), compType, N)
 

From 87097c8e106b852938fefd0d0a170d6dc3c1e86a Mon Sep 17 00:00:00 2001
From: David Mak <david.18.19.21@gmail.com>
Date: Sat, 14 Mar 2026 18:20:56 +0800
Subject: [PATCH 14/16] wasm: Update `Ctx` documentation

---
 hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala
index 2395ab5cc9..f863f013b4 100644
--- a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala
+++ b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala
@@ -285,7 +285,7 @@ class Ctx(
 
   import Ctx.prettyString
 
-  /** Monotonically increasing counter for generating object tags. */
+  /** Counter for generating object tags. */
   private var objectTagNum = 0
 
   private val wasmIntrinsicFuncs: MutMap[Str, FuncIdx] = MutMap.empty

From 4ef7968ea6ba818132d55b913a0a02e767b7c7c8 Mon Sep 17 00:00:00 2001
From: David Mak <david.18.19.21@gmail.com>
Date: Sat, 14 Mar 2026 18:21:38 +0800
Subject: [PATCH 15/16] wasm: Remove redundant tag number check

---
 hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala
index f863f013b4..edaae538a0 100644
--- a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala
+++ b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala
@@ -316,7 +316,7 @@ class Ctx(
   def getFreshObjectTag(): Int =
     val tag = objectTagNum
     objectTagNum += 1
-    tag ensuring objectTagNum > tag
+    tag
 
   /** Adds a type into this context. */
   def addType(sym: Opt[BlockMemberSymbol], typeInfo: TypeInfo): TypeIdx =

From b1185fc771143f16548ad426d8ad049caae01c8f Mon Sep 17 00:00:00 2001
From: David Mak <david.18.19.21@gmail.com>
Date: Sat, 14 Mar 2026 18:30:01 +0800
Subject: [PATCH 16/16] wasm: Fix typo

---
 hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala
index edaae538a0..bac8355032 100644
--- a/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala
+++ b/hkmc2/shared/src/main/scala/hkmc2/codegen/wasm/text/Ctx.scala
@@ -462,7 +462,7 @@ class Ctx(
         val localIdx = idx.toInt - functionImports.size
         if localIdx < 0 then N else funcs.unapply(localIdx)
     case FuncIdx(SymIdx(nme)) =>
-      // TODO(Derppening): Consider adding a `Map[SymIdx, TypeInfo]` for faster lookup
+      // TODO(Derppening): Consider adding a `Map[SymIdx, FuncInfo]` for faster lookup
       funcs.find(_.id.id == nme)
     case funcref: Symbol => namedFuncs.get(funcref).map(idx => funcs(idx))