Concurrent Clean : Parser Combinator

プログラミング

ちょっと分かってきた

module paren

import StdEnv
import Parsers

Start
    # res = parse wholeparse ['()((()*1'] "" ""
    = case res of
        Succ r = hd r
        Err a b pos  = abort (foldl printPos "error" pos)
            with
                printPos s (At pos)
                    = s +++ " at " +++ (toString pos)
                printPos s (EndAt pos)
                    = s +++ " end at " +++ (toString pos)





Tree  = Bin (Tree,Tree)


        | Nil

wholeparse = parens <&&> empty <@ (\(x,_) -> x)

parens =
        (open &> parens <& close) <&&> parens
            //<@ (\(x,y) -> max (x+1) y)
            <@ (\(x,y) -> Bin (x,y))
    <|> yield Nil
    //empty
    //    <@ (\(x,y) -> 0)

open  = symbolH '('
close = symbolH ')'

*1:))r)(