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Diffstat (limited to 'libraries/ghc-boot/GHC/Lexeme.hs')
| -rw-r--r-- | libraries/ghc-boot/GHC/Lexeme.hs | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/libraries/ghc-boot/GHC/Lexeme.hs b/libraries/ghc-boot/GHC/Lexeme.hs new file mode 100644 index 0000000000..677c9a65e6 --- /dev/null +++ b/libraries/ghc-boot/GHC/Lexeme.hs @@ -0,0 +1,32 @@ +----------------------------------------------------------------------------- +-- | +-- Module : GHC.Lexeme +-- Copyright : (c) The GHC Team +-- +-- Maintainer : ghc-devs@haskell.org +-- Portability : portable +-- +-- Functions to evaluate whether or not a string is a valid identifier. +-- +module GHC.Lexeme ( + -- * Lexical characteristics of Haskell names + startsVarSym, startsVarId, startsConSym, startsConId, + startsVarSymASCII, isVarSymChar + ) where + +import Data.Char + +startsVarSym, startsVarId, startsConSym, startsConId :: Char -> Bool +startsVarSym c = startsVarSymASCII c || (ord c > 0x7f && isSymbol c) -- Infix Ids +startsConSym c = c == ':' -- Infix data constructors +startsVarId c = c == '_' || case generalCategory c of -- Ordinary Ids + LowercaseLetter -> True + OtherLetter -> True -- See #1103 + _ -> False +startsConId c = isUpper c || c == '(' -- Ordinary type constructors and data constructors + +startsVarSymASCII :: Char -> Bool +startsVarSymASCII c = c `elem` "!#$%&*+./<=>?@\\^|~-" + +isVarSymChar :: Char -> Bool +isVarSymChar c = c == ':' || startsVarSym c |