# File examples/eyapplanguageref/Postfix.eyp # Compile it with: eyapp -C Postfix.eyp # Execution: ./Postfix.pm -c 'a = 2*3 +b' %token NUM = /([0-9]+(?:\.[0-9]+)?)/ %token VAR = /([A-Za-z][A-Za-z0-9_]*)/ %right '=' %left '-' '+' %left '*' '/' %left NEG %defaultaction { "$left $right $op"; } %% line: $exp { print "$exp\n" } ; exp: $NUM { $NUM } | $VAR { $VAR } | VAR.left '='.op exp.right | exp.left '+'.op exp.right | exp.left '-'.op exp.right | exp.left '*'.op exp.right | exp.left '/'.op exp.right | '-' $exp %prec NEG { "$exp NEG" } | '(' $exp ')' { $exp } ; %%