shithub: MicroHs

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--- a/lib/Data/Enum.hs

+++ b/lib/Data/Enum.hs

@@ -68,3 +68,13 @@

 instance Enum Char where

   fromEnum = primOrd

   toEnum   = primChr

+

+

+instance Enum Ordering where

+  fromEnum LT = (0::Int)

+  fromEnum EQ = (1::Int)

+  fromEnum GT = (2::Int)

+  toEnum i =      if i `primIntEQ` 0 then LT

+             else if i `primIntEQ` 1 then EQ

+             else if i `primIntEQ` 2 then GT

+             else error "Ord.toEnum: out of range"

--- a/lib/Data/Ord.hs

+++ b/lib/Data/Ord.hs

@@ -46,4 +46,3 @@

 instance Bounded Ordering where

   minBound = LT

   maxBound = GT

-

--- a/lib/Text/Read.hs

+++ b/lib/Text/Read.hs

@@ -14,11 +14,13 @@

 import Control.Error

 import Data.Char

 import Data.Bool

+import Data.Either

 import Data.Eq

 import Data.Function

 import Data.List

 import Data.Maybe_Type

 import Data.Num

+import Data.Ord

 import Data.Int

 import Text.Read.Numeric

 import Text.Read.Lex

@@ -65,5 +67,18 @@

   readsPrec _ = readList

 instance Read Bool where

-  readsPrec _ s = [ (False, r) | ("False", r) <- lex s ] ++

-                  [ (True,  r) | ("True",  r) <- lex s ]

+  readsPrec _ = readBoundedEnum

+

+instance Read Ordering where

+  readsPrec _ = readBoundedEnum

+

+instance forall a . Read a => Read (Maybe a) where

+  readsPrec p u = [ (Nothing :: Maybe a, t) | ("Nothing", t) <- lex u ] ++

+                  readParen (p > 10) ( \ r ->

+                    [ (Just a,  t) | ("Just",    s) <- lex r, (a, t) <- readsPrec 11 s ]

+                    ) u

+

+instance forall a b . (Read a, Read b) => Read (Either a b) where

+  readsPrec p = readParen (p > 10) $ \ r ->

+                [ (Left  a, t) | ("Left",  s) <- lex r, (a, t) <- readsPrec 11 s ] ++

+                [ (Right b, t) | ("Right", s) <- lex r, (b, t) <- readsPrec 11 s ]

--- a/src/runtime/eval.c

+++ b/src/runtime/eval.c

@@ -2388,6 +2388,7 @@

       }

     case T_FROMUTF8:

+      if (doing_rnf) RET;

       CHECK(1);

       x = evali(ARG(TOP(0)));

       if (GETTAG(x) != T_STR) ERR("FROMUTF8");

--- a/tests/Read.hs

+++ b/tests/Read.hs

@@ -26,7 +26,7 @@

   print (read "-123"  :: Integer)

   print (read "(123)" :: Integer)

   print (read "1234567890123456789012345678901234567890" :: Integer)

-  print (read "[1,2,3]" :: [Int])

+  print (read "[1,2, 3]" :: [Int])

   print (read "False" :: Bool)

   print (read "True" :: Bool)

   print (reads "123 4" :: [(Int, String)])

@@ -37,3 +37,11 @@

   print (read "-1e+5" :: Double)

   print (read "1.5e+5" :: Double)

   print (read "5e-1" :: Double)

+  print (read "[EQ,GT,LT]" :: [Ordering])

+  print (read "Nothing" :: Maybe Int)

+  print (read "Just 123" :: Maybe Int)

+  print (read "Just (Just 123)" :: Maybe (Maybe Int))

+  print (read "Just Nothing" :: Maybe (Maybe Int))

+  print (readMaybe "Just Just 123" :: Maybe (Maybe (Maybe Int)))

+  print (read "Left True" :: Either Bool Int)

+  print (read "Right 123" :: Either Bool Int)

--- a/tests/Read.ref

+++ b/tests/Read.ref

@@ -27,3 +27,11 @@

 -100000.0

 150000.0

 0.5

+[EQ,GT,LT]

+Nothing

+Just 123

+Just (Just 123)

+Just Nothing

+Nothing

+Left True

+Right 123

-- 

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