Re: Why put type information into syntax?

Keith Thompson <kst@cts.com> writes:


> Perhaps your backtracking LR parser generator takes care of some of
> this for you, but I believe there are cases that *can't* be resolved
> without feedback from the symbol table. For example, how does your
> grammar handle the following?
>
> {
> typedef int foo;
> foo(x); /* This is a variable declaration. */
> bar(y); /* This is a function call.
> }


Would it be possible to deal with this by having the parser build
trees that retain the ambiguity, and then resolve it during a separate
semantic-analysis tree walk? Eg, in the above example, build a tree
that represents "a var decl or a function call", and then walk the
tree, using a symbol table to help transform it into one or the other?


I suspect not...


- Bob
[Sure, that's what Earley parsers do, but the performance hit can be
phenomenal. -John]

Return to the comp.compilers page.
Search the comp.compilers archives again.