definition module parse

from Data.Either import :: Either
from Data.Maybe import :: Maybe
from StdString import class toString

from lex import :: LexerOutput, :: Error, :: Token, :: TokenValue, :: Pos
from AST import :: AST, :: Expr

:: ParserOutput :== Either Error AST

parser :: [Token] -> ParserOutput
makeStrExpr :: Pos [Char] -> Expr