Parsector and more

CHANGELOG.md

@@ -1,5 +1,46 @@
 # Changelog for `distributors`
 
+## 0.4.0.0 - 2026-04-10
+
+### New Modules
+
+- `Control.Monad.Fail.Try` - `MonadTry` class with `try` & `fail` for backtracking parsers
+- `Data.Profunctor.Grammar.Parsector` - Invertible LL(1) parser with Parsec-style error reporting:
+  `ParsecState`, `ParsecError`, `parsecP`, `unparsecP`; implements hints, LL(1) commitment
+  via `parsecLooked`, and `try` for explicit backtracking
+- `Data.Profunctor.Separator` - Separator/delimiter combinators: `sepWith`, `noSep`,
+  `beginWith`, `endWith`, `several`, `several1`, `intercalateP`, `chain`, `chain1`
+- `Data.Traversable.Homogeneous` - `Homogeneous` class for static containers with uniform elements;
+  `ditraverse` for distributive traversals
+
+### New Combinators
+
+- `Control.Lens.Grammar.Kleene`: `tokenClass` embedding into `RegEx`; `KleeneAlgebra` laws
+  as QuickCheck properties; `RegExam` helpers `failExam`, `passExam`, `isFailExam`
+- `Control.Lens.Grammar.Boole`: `trueB`, `falseB` added to `BooleanAlgebra`;
+  `andB`, `orB`, `allB`, `anyB` fold combinators
+- `Data.Profunctor.Monadic`: `MonadicTry` constraint alias; `P.return` combinator;
+  improved documentation for qualified do-notation pattern bonding
+- `Data.Profunctor.Distributor`: `manyP` / `optionalP` now place the empty case on
+  the right of `>+<` for correct LL(1) behaviour (`p >*< manyP p >+< oneP`)
+
+### Changes
+
+- `<|>` in `Parsector` now commits when the left branch consumes input (LL(1));
+  use `try` to opt into backtracking
+- `TokenTest` renamed to `TokenClass` throughout
+- `chain`, `chain1`, `intercalateP` moved from `Data.Profunctor.Distributor`
+  to the new `Data.Profunctor.Separator`
+- `BackusNaurForm`: `rule` documentation clarified; added reference to Breitner's
+  *Showcasing Applicative*
+
+### Testing
+
+- `test/Properties/Kleene` - QuickCheck properties for `KleeneStarAlgebra`,
+  `TokenAlgebra`, `BooleanAlgebra TokenClass`
+- `test/Examples/Chain` - Chain grammar example
+- `test/Main`: `testCtxGrammarExample` extended with `parsecG` / `unparsecG` round-trip checks
+
 ## 0.3.0.0 - 2026-02-05
 
 ### New Modules

distributors.cabal

@@ -5,7 +5,7 @@ cabal-version: 2.2
 -- see: https://github.com/sol/hpack
 
 name:           distributors
-version:        0.3.0.0
+version:        0.4.0.0
 synopsis:       Unifying Parsers, Printers & Grammars
 description:    Distributors provides mathematically inspired abstractions for coders to write parsers that can also be inverted to printers.
 category:       Profunctors, Optics, Parsing
@@ -41,11 +41,15 @@ library
       Control.Lens.Monocle
       Control.Lens.PartialIso
       Control.Lens.Wither
+      Control.Monad.Fail.Try
       Data.Profunctor.Distributor
       Data.Profunctor.Filtrator
       Data.Profunctor.Grammar
+      Data.Profunctor.Grammar.Parsector
       Data.Profunctor.Monadic
       Data.Profunctor.Monoidal
+      Data.Profunctor.Separator
+      Data.Traversable.Homogeneous
   other-modules:
       Paths_distributors
   autogen-modules:
@@ -116,12 +120,14 @@ test-suite test
   main-is: Main.hs
   other-modules:
       Examples.Arithmetic
+      Examples.Chain
       Examples.Json
       Examples.Lambda
       Examples.LenVec
       Examples.RegString
       Examples.SemVer
       Examples.SExpr
+      Properties.Kleene
       Paths_distributors
   autogen-modules:
       Paths_distributors
@@ -168,6 +174,7 @@ test-suite test
   ghc-options: -Wall -Wcompat -Widentities -Wincomplete-record-updates -Wincomplete-uni-patterns -Wmissing-export-lists -Wmissing-home-modules -Wpartial-fields -Wredundant-constraints
   build-depends:
       MemoTrie >=0.6 && <1
+    , QuickCheck >=2.14 && <3
     , adjunctions >=4.4 && <5
     , base >=4.15 && <5
     , bifunctors >=5.5 && <6

package.yaml

@@ -1,5 +1,5 @@
 name: distributors
-version: 0.3.0.0
+version: 0.4.0.0
 github: "morphismtech/distributors"
 license: BSD-3-Clause
 author: "Eitan Chatav"
@@ -97,3 +97,4 @@ tests:
       - distributors
       - doctest >= 0.18 && < 1
       - hspec >= 2.7 && < 3
+      - QuickCheck >= 2.14 && < 3

src/Control/Lens/Bifocal.hs

@@ -39,6 +39,7 @@ import Control.Lens.PartialIso
 import Data.Profunctor
 import Data.Profunctor.Distributor
 import Data.Profunctor.Filtrator
+import Data.Profunctor.Separator
 import Witherable
 
 {- | `Bifocal`s are bidirectional parser optics.

src/Control/Lens/Diopter.hs

@@ -27,6 +27,7 @@ module Control.Lens.Diopter
 import Control.Lens
 import Control.Lens.Internal.Profunctor
 import Data.Profunctor.Distributor
+import Data.Traversable.Homogeneous
 import Data.Void
 import GHC.Generics
 
@@ -41,8 +42,7 @@ type Diopter s t a b = forall p f.
   (Distributor p, Applicative f)
     => p a (f b) -> p s (f t)
 
-{- | If you see `ADiopter` in a signature for a function,
-the function is expecting a `Diopter`. -}
+{- | `ADiopter` is monomorphically a `Diopter`. -}
 type ADiopter s t a b =
   Dioptrice a b a (Identity b) -> Dioptrice a b s (Identity t)