/usr/lib/hugs/packages/base/Text/Read.hs is in libhugs-base-bundled 98.200609.21-5.3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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-----------------------------------------------------------------------------
-- |
-- Module : Text.Read
-- Copyright : (c) The University of Glasgow 2001
-- License : BSD-style (see the file libraries/base/LICENSE)
--
-- Maintainer : libraries@haskell.org
-- Stability : provisional
-- Portability : non-portable (uses Text.ParserCombinators.ReadP)
--
-- Converting strings to values.
--
-- The "Text.Read" library is the canonical library to import for
-- 'Read'-class facilities. For GHC only, it offers an extended and much
-- improved 'Read' class, which constitutes a proposed alternative to the
-- Haskell 98 'Read'. In particular, writing parsers is easier, and
-- the parsers are much more efficient.
--
-----------------------------------------------------------------------------
module Text.Read (
-- * The 'Read' class
Read(..), -- The Read class
ReadS, -- String -> Maybe (a,String)
-- * Haskell 98 functions
reads, -- :: (Read a) => ReadS a
read, -- :: (Read a) => String -> a
readParen, -- :: Bool -> ReadS a -> ReadS a
lex, -- :: ReadS String
-- * New parsing functions
module Text.ParserCombinators.ReadPrec,
L.Lexeme(..),
lexP, -- :: ReadPrec Lexeme
parens, -- :: ReadPrec a -> ReadPrec a
) where
import Text.ParserCombinators.ReadPrec
import qualified Text.Read.Lex as L
-- copied from GHC.Read
lexP :: ReadPrec L.Lexeme
lexP = lift L.lex
parens :: ReadPrec a -> ReadPrec a
parens p = optional
where
optional = p +++ mandatory
mandatory = do
L.Punc "(" <- lexP
x <- reset optional
L.Punc ")" <- lexP
return x
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