{-# LANGUAGE PatternGuards #-}

module CppToken where

import Text.ParserCombinators.Parsec.Pos

type Token = (SourcePos, Tok)
data Tok =
    Identifier String
    | Reserved String

	-- Literals
    | StringTok String
    | IntegerTok Integer
    | CharTok Char
    
    -- Punctuation (most of them without semantical meaning)
    | Semicolon
    | OpenBrace
    | CloseBrace
    | OpenParen
    | CloseParen
    | OpenBracket
    | CloseBracket
    | Comma
    
    | DoubleColon
    | Ellipsis
    -- Member access
    | Dot
    | Arrow
    -- Not sure if these should be individual operators
    {-
    | DotStar
    | ArrowStar
    -}
    
    -- Pointer, dereference or multiplication
    | Asterix
    -- Both non-shortcut/bitwise and, reference and address-of
    | Ampersand
    | Plus
    | Minus
    | Division
    
    -- Logic operators
    | ShortcutAnd
    | ShortcutOr
    | LogicalNot
    | Complement
    | Or
    
    | LessThan
    | GreaterThan
    | GreaterOrEqual
    | LessOrEqual
    | Equal
    | NotEqual
    
    -- Part one of ?:
    | QuestionMark
    -- Part two of :
    | SingleColon
    
    -- Assignment =
    | Assignment
    
    | LeftShift
    | RightShift
    deriving (Show, Eq, Ord)

line n = setSourceLine (initialPos "hard-coded") n

oneCharOperators = zip ";{}()[],.*&+-/!~|<>?:=" $
	[Semicolon
	,OpenBrace
	,CloseBrace
	,OpenParen
	,CloseParen
	,OpenBracket
	,CloseBracket
	,Comma
	,Dot
	,Asterix
	,Ampersand
	,Plus
	,Minus
	,Division
	,LogicalNot
	,Complement
	,Or
	,LessThan
	,GreaterThan
	,QuestionMark
	,SingleColon
	,Assignment]

multiCharOperators =
	[("&&",ShortcutAnd)
	,("||",ShortcutOr)
	,("::",DoubleColon)
	,("...",Ellipsis)
	,("->",Arrow)
	,(">=",GreaterOrEqual)
	,("<=",LessOrEqual)
	,("==",Equal)
	,("!=",NotEqual)
	,("<<",LeftShift)
	,(">>",RightShift)]

reservedWords =
	["char"
	,"class"
	,"const"
	,"double"
	,"enum"
	,"extern"
	,"float"
	,"friend"
	,"int"
	,"long"
	,"namespace"
	,"return"
	,"struct"
	,"template"
	,"typedef"
	,"typename"
	,"unsigned"
	,"using"
	,"void"
	,"volatile"]

swap (x,y) = (y,x)
printCanonically Semicolon = ";\n"
printCanonically token = (case token of
	_ | Just c <- lookup token (map swap oneCharOperators) -> [c]
	_ | Just str <- lookup token (map swap multiCharOperators) -> str
	Reserved word -> word
	Identifier ident -> ident
	StringTok s -> show s
	IntegerTok i -> show i
	otherwise -> "/*"++show token++"*/") ++ " "