[Git][ghc/ghc][wip/jeltsch/text-read-uncovering] 2 commits: Move the implementation of version parsing into `base`

18 Mar 2026

Wolfgang Jeltsch pushed to branch wip/jeltsch/text-read-uncovering at Glasgow Haskell Compiler / GHC


Commits:
40d2e59f by Wolfgang Jeltsch at 2026-03-18T23:41:54+02:00
Move the implementation of version parsing into `base`

- - - - -
b2122fdb by Wolfgang Jeltsch at 2026-03-18T23:42:09+02:00
Move the implementation of `readConstr` into `base`

- - - - -


9 changed files:

- libraries/base/src/Data/Data.hs
- libraries/base/src/Data/Version.hs
- libraries/ghc-internal/src/GHC/Internal/Data/Data.hs
- libraries/ghc-internal/src/GHC/Internal/Data/Version.hs
- testsuite/tests/interface-stability/base-exports.stdout
- testsuite/tests/interface-stability/base-exports.stdout-javascript-unknown-ghcjs
- testsuite/tests/interface-stability/base-exports.stdout-mingw32
- testsuite/tests/interface-stability/base-exports.stdout-ws-32
- testsuite/tests/plugins/plugins10.stdout


Changes:

=====================================
libraries/base/src/Data/Data.hs
=====================================
@@ -99,3 +99,38 @@ module Data.Data (
 
 import GHC.Internal.Data.Data
 import Data.Typeable
+
+import GHC.Real (toRational)
+import GHC.Float (Double)
+import Data.Eq ((==))
+import Data.Function ((.))
+import Data.Maybe (Maybe (Nothing, Just))
+import Data.List (filter)
+import Data.String (String)
+import Text.Read (Read, reads)
+
+-- | Lookup a constructor via a string
+readConstr :: DataType -> String -> Maybe Constr
+readConstr dt str =
+      case dataTypeRep dt of
+        AlgRep cons -> idx cons
+        IntRep      -> mkReadCon (\i -> (mkPrimCon dt str (IntConstr i)))
+        FloatRep    -> mkReadCon ffloat
+        CharRep     -> mkReadCon (\c -> (mkPrimCon dt str (CharConstr c)))
+        NoRep       -> Nothing
+  where
+
+    -- Read a value and build a constructor
+    mkReadCon :: Read t => (t -> Constr) -> Maybe Constr
+    mkReadCon f = case (reads str) of
+                    [(t,"")] -> Just (f t)
+                    _ -> Nothing
+
+    -- Traverse list of algebraic datatype constructors
+    idx :: [Constr] -> Maybe Constr
+    idx cons = case filter ((==) str . showConstr) cons of
+                [] -> Nothing
+                hd : _ -> Just hd
+
+    ffloat :: Double -> Constr
+    ffloat =  mkPrimCon dt str . FloatConstr . toRational


=====================================
libraries/base/src/Data/Version.hs
=====================================
@@ -1,5 +1,7 @@
 {-# LANGUAGE Safe #-}
 
+{-# LANGUAGE StandaloneDeriving #-}
+
 -- |
 -- Module      :  Data.Version
 -- Copyright   :  (c) The University of Glasgow 2004
@@ -33,3 +35,25 @@ module Data.Version (
       ) where
 
 import GHC.Internal.Data.Version
+
+import Control.Applicative (pure, (*>))
+import Data.Functor (fmap)
+import Data.Char (isDigit, isAlphaNum)
+import Text.ParserCombinators.ReadP (ReadP, char, munch1, sepBy1, many)
+import Text.Read (Read, read)
+
+{-NOTE:
+    The following instance is technically an orphan, but practically it is not,
+    since ordinary users should not use @ghc-internal@ directly and thus get
+    'Version' only through this module.
+-}
+
+-- | @since base-2.01
+deriving instance Read Version
+
+-- | A parser for versions in the format produced by 'showVersion'.
+--
+parseVersion :: ReadP Version
+parseVersion = do branch <- sepBy1 (fmap read (munch1 isDigit)) (char '.')
+                  tags   <- many (char '-' *> munch1 isAlphaNum)
+                  pure Version{versionBranch=branch, versionTags=tags}


=====================================
libraries/ghc-internal/src/GHC/Internal/Data/Data.hs
=====================================
@@ -61,6 +61,7 @@ module GHC.Internal.Data.Data (
         mkIntType,
         mkFloatType,
         mkCharType,
+        mkPrimCon,
         mkNoRepType,
         -- ** Observers
         dataTypeName,
@@ -94,7 +95,6 @@ module GHC.Internal.Data.Data (
         constrIndex,
         -- ** From strings to constructors and vice versa: all data types
         showConstr,
-        readConstr,
 
         -- * Convenience functions: take type constructors apart
         tyconUQname,
@@ -126,10 +126,8 @@ import GHC.Internal.Base (
 import GHC.Internal.Err (errorWithoutStackTrace)
 import GHC.Internal.List
 import GHC.Internal.Num
-import GHC.Internal.Read
 import GHC.Internal.Show
 import GHC.Internal.Tuple (Solo (..))
-import GHC.Internal.Text.Read( reads )
 import GHC.Internal.Types (
     Bool(..), Char, Coercible, Float, Double, Type, type (~), type (~~),
   )
@@ -688,32 +686,6 @@ showConstr :: Constr -> String
 showConstr = constring

--- | Lookup a constructor via a string
-readConstr :: DataType -> String -> Maybe Constr
-readConstr dt str =
-      case dataTypeRep dt of
-        AlgRep cons -> idx cons
-        IntRep      -> mkReadCon (\i -> (mkPrimCon dt str (IntConstr i)))
-        FloatRep    -> mkReadCon ffloat
-        CharRep     -> mkReadCon (\c -> (mkPrimCon dt str (CharConstr c)))
-        NoRep       -> Nothing
-  where
-
-    -- Read a value and build a constructor
-    mkReadCon :: Read t => (t -> Constr) -> Maybe Constr
-    mkReadCon f = case (reads str) of
-                    [(t,"")] -> Just (f t)
-                    _ -> Nothing
-
-    -- Traverse list of algebraic datatype constructors
-    idx :: [Constr] -> Maybe Constr
-    idx cons = case filter ((==) str . showConstr) cons of
-                [] -> Nothing
-                hd : _ -> Just hd
-
-    ffloat :: Double -> Constr
-    ffloat =  mkPrimCon dt str . FloatConstr . toRational
-
 ------------------------------------------------------------------------------
 --
 --      Convenience functions: algebraic data types


=====================================
libraries/ghc-internal/src/GHC/Internal/Data/Version.hs
=====================================
@@ -10,7 +10,7 @@
 --
 -- Maintainer  :  libraries@haskell.org
 -- Stability   :  stable
--- Portability :  non-portable (local universal quantification in ReadP)
+-- Portability :  non-portable
 --
 -- A general library for representation and manipulation of versions.
 --
@@ -31,23 +31,18 @@ module GHC.Internal.Data.Version (
         -- * The @Version@ type
         Version(..),
         -- * A concrete representation of @Version@
-        showVersion, parseVersion,
+        showVersion,
         -- * Constructor function
         makeVersion
   ) where
 
-import GHC.Internal.Classes          ( Eq(..), (&&) )
-import GHC.Internal.Data.Functor     ( Functor(..) )
+import GHC.Internal.Classes          ( Eq ((==)), (&&) )
 import GHC.Internal.Int              ( Int )
 import GHC.Internal.Data.List        ( map, sort, concat, concatMap, intersperse, (++) )
 import GHC.Internal.Data.Ord
-import GHC.Internal.Base             ( Applicative(..), String )
+import GHC.Internal.Base             ( String )
 import GHC.Internal.Generics
-import GHC.Internal.Unicode          ( isDigit, isAlphaNum )
-import GHC.Internal.Read
 import GHC.Internal.Show
-import GHC.Internal.Text.ParserCombinators.ReadP
-import GHC.Internal.Text.Read        ( read )
 
 {- |
 A 'Version' represents the version of a software entity.
@@ -69,8 +64,8 @@ operations are the right thing for every 'Version'.
 
 Similarly, concrete representations of versions may differ.  One
 possible concrete representation is provided (see 'showVersion' and
-'parseVersion'), but depending on the application a different concrete
-representation may be more appropriate.
+'Data.Version.parseVersion'), but depending on the application a
+different concrete representation may be more appropriate.
 -}
 data Version =
   Version { versionBranch :: [Int],
@@ -92,8 +87,7 @@ data Version =
                 -- The interpretation of the list of tags is entirely dependent
                 -- on the entity that this version applies to.
         }
-  deriving ( Read    -- ^ @since base-2.01
-           , Show    -- ^ @since base-2.01
+  deriving ( Show    -- ^ @since base-2.01
            , Generic -- ^ @since base-4.9.0.0
            )
 {-# DEPRECATED versionTags "See GHC ticket #2496" #-}
@@ -121,13 +115,6 @@ showVersion (Version branch tags)
   = concat (intersperse "." (map show branch)) ++
      concatMap ('-':) tags
 
--- | A parser for versions in the format produced by 'showVersion'.
---
-parseVersion :: ReadP Version
-parseVersion = do branch <- sepBy1 (fmap read (munch1 isDigit)) (char '.')
-                  tags   <- many (char '-' *> munch1 isAlphaNum)
-                  pure Version{versionBranch=branch, versionTags=tags}
-
 -- | Construct tag-less 'Version'
 --
 -- @since base-4.8.0.0


=====================================
testsuite/tests/interface-stability/base-exports.stdout
=====================================
@@ -12496,7 +12496,7 @@ instance forall a. GHC.Internal.Read.Read a => GHC.Internal.Read.Read (Data.Semi
 instance forall a. GHC.Internal.Read.Read a => GHC.Internal.Read.Read (Data.Semigroup.Min a) -- Defined in ‘Data.Semigroup’
 instance forall m. GHC.Internal.Read.Read m => GHC.Internal.Read.Read (Data.Semigroup.WrappedMonoid m) -- Defined in ‘Data.Semigroup’
 instance forall k (a :: k) (b :: k). Coercible a b => GHC.Internal.Read.Read (GHC.Internal.Data.Type.Coercion.Coercion a b) -- Defined in ‘GHC.Internal.Data.Type.Coercion’
-instance GHC.Internal.Read.Read GHC.Internal.Data.Version.Version -- Defined in ‘GHC.Internal.Data.Version’
+instance [safe] GHC.Internal.Read.Read GHC.Internal.Data.Version.Version -- Defined in ‘Data.Version’
 instance GHC.Internal.Read.Read GHC.Internal.Foreign.Ptr.IntPtr -- Defined in ‘GHC.Internal.Foreign.Ptr’
 instance GHC.Internal.Read.Read GHC.Internal.Foreign.Ptr.WordPtr -- Defined in ‘GHC.Internal.Foreign.Ptr’
 instance GHC.Internal.Read.Read GHC.Internal.Foreign.C.Types.CBool -- Defined in ‘GHC.Internal.Foreign.C.Types’


=====================================
testsuite/tests/interface-stability/base-exports.stdout-javascript-unknown-ghcjs
=====================================
@@ -12525,7 +12525,7 @@ instance forall a. GHC.Internal.Read.Read a => GHC.Internal.Read.Read (Data.Semi
 instance forall a. GHC.Internal.Read.Read a => GHC.Internal.Read.Read (Data.Semigroup.Min a) -- Defined in ‘Data.Semigroup’
 instance forall m. GHC.Internal.Read.Read m => GHC.Internal.Read.Read (Data.Semigroup.WrappedMonoid m) -- Defined in ‘Data.Semigroup’
 instance forall k (a :: k) (b :: k). Coercible a b => GHC.Internal.Read.Read (GHC.Internal.Data.Type.Coercion.Coercion a b) -- Defined in ‘GHC.Internal.Data.Type.Coercion’
-instance GHC.Internal.Read.Read GHC.Internal.Data.Version.Version -- Defined in ‘GHC.Internal.Data.Version’
+instance [safe] GHC.Internal.Read.Read GHC.Internal.Data.Version.Version -- Defined in ‘Data.Version’
 instance GHC.Internal.Read.Read GHC.Internal.Foreign.Ptr.IntPtr -- Defined in ‘GHC.Internal.Foreign.Ptr’
 instance GHC.Internal.Read.Read GHC.Internal.Foreign.Ptr.WordPtr -- Defined in ‘GHC.Internal.Foreign.Ptr’
 instance GHC.Internal.Read.Read GHC.Internal.Foreign.C.Types.CBool -- Defined in ‘GHC.Internal.Foreign.C.Types’


=====================================
testsuite/tests/interface-stability/base-exports.stdout-mingw32
=====================================
@@ -12767,7 +12767,7 @@ instance forall a. GHC.Internal.Read.Read a => GHC.Internal.Read.Read (Data.Semi
 instance forall a. GHC.Internal.Read.Read a => GHC.Internal.Read.Read (Data.Semigroup.Min a) -- Defined in ‘Data.Semigroup’
 instance forall m. GHC.Internal.Read.Read m => GHC.Internal.Read.Read (Data.Semigroup.WrappedMonoid m) -- Defined in ‘Data.Semigroup’
 instance forall k (a :: k) (b :: k). Coercible a b => GHC.Internal.Read.Read (GHC.Internal.Data.Type.Coercion.Coercion a b) -- Defined in ‘GHC.Internal.Data.Type.Coercion’
-instance GHC.Internal.Read.Read GHC.Internal.Data.Version.Version -- Defined in ‘GHC.Internal.Data.Version’
+instance [safe] GHC.Internal.Read.Read GHC.Internal.Data.Version.Version -- Defined in ‘Data.Version’
 instance GHC.Internal.Read.Read GHC.Internal.Foreign.Ptr.IntPtr -- Defined in ‘GHC.Internal.Foreign.Ptr’
 instance GHC.Internal.Read.Read GHC.Internal.Foreign.Ptr.WordPtr -- Defined in ‘GHC.Internal.Foreign.Ptr’
 instance GHC.Internal.Read.Read GHC.Internal.Foreign.C.Types.CBool -- Defined in ‘GHC.Internal.Foreign.C.Types’


=====================================
testsuite/tests/interface-stability/base-exports.stdout-ws-32
=====================================
@@ -12496,7 +12496,7 @@ instance forall a. GHC.Internal.Read.Read a => GHC.Internal.Read.Read (Data.Semi
 instance forall a. GHC.Internal.Read.Read a => GHC.Internal.Read.Read (Data.Semigroup.Min a) -- Defined in ‘Data.Semigroup’
 instance forall m. GHC.Internal.Read.Read m => GHC.Internal.Read.Read (Data.Semigroup.WrappedMonoid m) -- Defined in ‘Data.Semigroup’
 instance forall k (a :: k) (b :: k). Coercible a b => GHC.Internal.Read.Read (GHC.Internal.Data.Type.Coercion.Coercion a b) -- Defined in ‘GHC.Internal.Data.Type.Coercion’
-instance GHC.Internal.Read.Read GHC.Internal.Data.Version.Version -- Defined in ‘GHC.Internal.Data.Version’
+instance [safe] GHC.Internal.Read.Read GHC.Internal.Data.Version.Version -- Defined in ‘Data.Version’
 instance GHC.Internal.Read.Read GHC.Internal.Foreign.Ptr.IntPtr -- Defined in ‘GHC.Internal.Foreign.Ptr’
 instance GHC.Internal.Read.Read GHC.Internal.Foreign.Ptr.WordPtr -- Defined in ‘GHC.Internal.Foreign.Ptr’
 instance GHC.Internal.Read.Read GHC.Internal.Foreign.C.Types.CBool -- Defined in ‘GHC.Internal.Foreign.C.Types’


=====================================
testsuite/tests/plugins/plugins10.stdout
=====================================
@@ -2,6 +2,7 @@ parsePlugin()
 interfacePlugin: Prelude
 interfacePlugin: Language.Haskell.TH
 interfacePlugin: Language.Haskell.TH.Quote
+interfacePlugin: Data.Version
 interfacePlugin: System.IO
 interfacePlugin: GHC.Internal.Base
 interfacePlugin: GHC.Internal.Data.NonEmpty



View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/a78ea8163e36526842596c5b764a2f0...

-- 
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/a78ea8163e36526842596c5b764a2f0...
You're receiving this email because of your account on gitlab.haskell.org.

    

Wolfgang Jeltsch (＠jeltsch)

tags

participants (1)