-- | 
-- Module      : Language.Go.Parser.Tokens
-- Copyright   : (c) 2011 Andrew Robbins
-- License     : GPLv3 (see COPYING)
-- 
-- x
module Language.Go.Parser.Tokens where
import Language.Go.Syntax.AST (GoSource)
import Text.Parsec.String
import Text.Parsec.Prim
import Text.Parsec.Pos (SourcePos(..))

-- | GoTokener is the type used for all tokenizers
-- type GoTokener = GenParser Char () [GoToken]

-- | GoParser is the type used for all parsers
type GoParser a = GenParser GoTokenPos () a

-- | GoTokenPos encodes tokens and source positions
data GoTokenPos = GoTokenPos !SourcePos !GoToken
                  deriving (Eq, Show)

-- | GoToken encodes tokens
data GoToken = GoTokNone
             | GoTokComment Bool String
-- BEGIN literals
             | GoTokInteger (Maybe String) Integer
             | GoTokFloat   (Maybe String) Float
             | GoTokFloatI  (Maybe String) Float
             | GoTokChar    (Maybe String) Char
             | GoTokString  (Maybe String) String
-- END literals
-- BEGIN wraps
             | GoTokLParen   -- '('
             | GoTokRParen   -- ')'
             | GoTokLBrace   -- '{'
             | GoTokRBrace   -- '}'
             | GoTokLBracket -- '['
             | GoTokRBracket -- ']'
-- END wraps
-- BEGIN keywords
             | GoTokBreak
             | GoTokCase
             | GoTokChan
             | GoTokConst
             | GoTokContinue
             | GoTokDefault
             | GoTokDefer
             | GoTokElse
             | GoTokFallthrough
             | GoTokFor
             | GoTokFunc
             | GoTokGo
             | GoTokGoto
             | GoTokIf
             | GoTokImport
             | GoTokInterface
             | GoTokMap
             | GoTokPackage
             | GoTokRange
             | GoTokReturn
             | GoTokSelect
             | GoTokStruct
             | GoTokSwitch
             | GoTokType
             | GoTokVar
-- END keywords
             | GoTokSemicolonAuto
             | GoTokSemicolon -- ';'
             | GoTokColon     -- ':'
             | GoTokComma     -- ','
             | GoTokFullStop  -- '.'
             | GoTokAsterisk  -- '*'
             | GoTokElipsis   -- '...'
             | GoTokDec       -- '--'
             | GoTokInc       -- '++'
-- BEGIN names
             | GoTokId String
             | GoTokOp String
-- END names
               deriving (Eq, Read, Show)
-- Data, Typeable

tokenSimplify :: (Int, Int) -> String -> String
tokenSimplify (n, m) s = map (s!!) [n..(length s)-m-1]

tokenFromId :: String -> GoToken
tokenFromId s = GoTokId $ if s!!0 == '#' && s!!1 == '['
                          then tokenSimplify (2, 1) s
                          else s

tokenFromOp :: String -> GoToken
tokenFromOp s = GoTokOp $ if s!!0 == '#' && s!!1 == '{'
                          then tokenSimplify (2, 1) s
                          else s

-- False=singleline True=multiline
tokenFromComment :: Bool -> String -> GoToken
tokenFromComment False s = GoTokComment False $ tokenSimplify (2, 1) s
tokenFromComment True  s = GoTokComment True  $ tokenSimplify (2, 2) s

tokenFromInt :: String -> GoToken
tokenFromInt s = GoTokInteger (Just s) $ ((read s) :: Integer)

tokenFromReal :: String -> GoToken
tokenFromReal s = GoTokFloat (Just s) $ (read s)

tokenFromImag :: String -> GoToken
tokenFromImag s = GoTokFloatI (Just s) $ (read $ init s)

tokenFromRawStr :: String -> GoToken
tokenFromRawStr s = GoTokString (Just s) $ tokenSimplify (1, 1) s

-- TODO: process \u#### and stuff
tokenFromString :: String -> GoToken
tokenFromString s = GoTokString (Just s) $ tokenSimplify (1, 1) s

tokenFromChar :: String -> GoToken
tokenFromChar s = GoTokChar (Just s) (s!!1)