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-- This module demonstrates a bug in the original 1.11 release of Happy.
{
module Main where
import System.IO
import Control.Exception as Exception
}
%name parse
%tokentype { Tok }
%token
'+' { Plus }
'/' { Divide }
int { Num $$ }
%left '+'
%left '*'
%nonassoc '/'
%%
E : E '+' E { Plus' $1 $3 }
| E '/' E { Divide' $1 $3 }
| int { Num' $1 }
{
happyError :: [Tok] -> a
happyError s = error (concatMap show s)
data Tok = Plus | Divide | Num Int deriving Show
data Syn = Plus' Syn Syn | Divide' Syn Syn | Num' Int deriving Show
-- due to a bug in conflict resolution, this caused a parse error:
tokens1 = [Num 6, Divide, Num 7, Plus, Num 8]
main = print (parse tokens1)
}
|
