File: VarParen.lg

package info (click to toggle)
frown 0.6.1-13
  • links: PTS, VCS
  • area: main
  • in suites: wheezy
  • size: 9,956 kB
  • sloc: haskell: 35,132; makefile: 228; csh: 35; yacc: 23
file content (18 lines) | stat: -rw-r--r-- 421 bytes parent folder | download | duplicates (6) 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
 
> module VarParen where
> import Result
>
> newtype Tree                  =  Node [Tree]
>                                  deriving (Show)
>
> %{
>
> Terminal                      =  '(' | ')';
>
> Nonterminal                   =  paren {Tree};
>
> paren  {Node []}              :  ;
>        {Node (x : xs)}        |  paren {x}, '(', paren {Node xs}, ')';
>
> }%
>
> frown ts                      =  fail "syntax error"