Version française
Home     About     Download     Resources     Contact us    
Browse thread
camlp4 parser accepts more than its grammar?
[ Home ] [ Index: by date | by threads ]
[ Search: ]

[ Message by date: previous | next ] [ Message in thread: previous | next ] [ Thread: previous | next ]
Date: -- (:)
From: Jake Donham <jake@d...>
Subject: camlp4 parser accepts more than its grammar? 
Hi list,

I expected the following program to fail with a parse error, but it
happily ignores the extra '+'. I would be grateful if someone could
point out what I'm doing wrong. Thanks,

Jake


open Camlp4.PreCast;;

let expr = Gram.Entry.mk "expr";;
let stmt = Gram.Entry.mk "stmt";;

EXTEND Gram
  expr: [[
    x = expr; "+"; y = expr -> x + y
  | x = INT -> int_of_string x
  ]];
  stmt:
  [[ e = expr; ";"; `EOI -> e ]];
END;;

prerr_endline (string_of_int (Gram.parse_string stmt Loc.ghost "2 + 1 + ;"))