On 11/30/2009 12:32 PM, Chad J wrote:
Ellery Newcomer wrote:
On 11/30/2009 03:53 AM, Ary Borenszweig wrote:
Chad J wrote:
Given an Expression object in dmd, I'd like to know how many
subexpressions it contains and, even better, iterate over them. I'd
like to do this in a general way, without having to create cases for all
of the different kinds of Expressions. Is there some way to do this
that I've been missing?
Thanks,
- Chad
Where's the Expression object defined in D? I don't think there's such a
thing (I mean, a reflection capability to get an expression out of
something).
DMD source, eg parse.c, expression.c, etc
Right. That.
Not that I know anything about DMD outside parse.c, but in expression.h,
there be decls along the lines of
struct UnaExp{
Expression* e1;
}
struct BinExp{
Expression* e1;
Expression* e2;
}
Iterating them would just be a tree walk. That takes care of 90% and ...
Oh. Yeah. There are a bunch of special cases.
But from what I've seen, iterating over an expression or any part of the
AST involves implementing a function (like semantic) at each subclass.
I'm betting there is no other way to do this.
I love ANTLR. It generates an arbitrary child/sibling AST, and walking
it is a piece of cake.
