Re: Why only one "expected"?

[Duncan Murdoch]

On 5/29/2007 10:05 AM, Duncan Murdoch wrote:
> We're using a GNU Bison 2.3 parser, with verbose error messages. 
> However, we only see messages with a single "expected" token.  For 
> example, if a user forgets to give a function name in a function call 
> and types "(1,1)" they'll get the error
>
> syntax error, unexpected ',', expecting ')'
>
> when in fact there are lots of legal tokens at that spot:  any 
> arithmetic operator would be fine, such as "(1+1)", "(1-1)", etc.

Sorry about the noise.  I see what's happening now.  One of the rules we 
have is

expr : '(' expr_or_assign ')'

and the first "1" is matching the expr_or_assign rule, so ')' really is 
the only possibility at that point.

Duncan Murdoch