Add preliminary support for PostgreSQL ranges

changelog.d/20260322_223524_shane.obrien_range.md

@@ -0,0 +1,3 @@
+### Added
+
+- Added preliminary support for PostgreSQL ranges.

rel8.cabal

@@ -33,6 +33,7 @@ library
     , hasql >= 1.8 && < 1.10
     , iproute ^>= 1.7
     , opaleye ^>= 0.10.2.1
+    , postgresql-binary ^>= 0.14.2
     , pretty
     , profunctors
     , product-profunctors
@@ -70,13 +71,15 @@ library
     Rel8.Expr.Num
     Rel8.Expr.Text
     Rel8.Expr.Time
+    Rel8.Range
     Rel8.Table.Verify
     Rel8.Tabulate
 
   other-modules:
     Rel8.Aggregate
     Rel8.Aggregate.Fold
     Rel8.Aggregate.Function
+    Rel8.Aggregate.Range
 
     Rel8.Column
     Rel8.Column.ADT
@@ -88,6 +91,8 @@ library
     Rel8.Column.Null
     Rel8.Column.These
 
+    Rel8.Data.Range
+
     Rel8.Expr
     Rel8.Expr.Aggregate
     Rel8.Expr.Array
@@ -101,6 +106,7 @@ library
     Rel8.Expr.Opaleye
     Rel8.Expr.Ord
     Rel8.Expr.Order
+    Rel8.Expr.Range
     Rel8.Expr.Read
     Rel8.Expr.Sequence
     Rel8.Expr.Serialize
@@ -239,6 +245,7 @@ library
     Rel8.Type.Parser
     Rel8.Type.Parser.ByteString
     Rel8.Type.Parser.Time
+    Rel8.Type.Range
     Rel8.Type.ReadShow
     Rel8.Type.Semigroup
     Rel8.Type.String

src/Rel8/Aggregate/Range.hs

@@ -0,0 +1,21 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Rel8.Aggregate.Range (
+  rangeAgg,  
+) where
+
+-- base
+import Prelude
+
+-- rel8
+import Rel8.Aggregate (Aggregator', toAggregator)
+import Rel8.Aggregate.Function (aggregateFunction)
+import Rel8.Data.Range (Multirange, Range)
+import Rel8.Expr (Expr)
+import Rel8.Type.Range (DBRange)
+
+
+rangeAgg ::
+  DBRange a =>
+  Aggregator' fold (Expr (Range a)) (Expr (Multirange a))
+rangeAgg = toAggregator mempty $ aggregateFunction "range_agg"