[antlr-interest] Anyone in the whole world doing multi step tree transformation?
oliver.zeigermann at gmail.com
Mon Jan 25 01:00:27 PST 2010
Thanks for your help. Two questions:
1.) This does not help when you do major refactorings, doest it ;)
2.) Where do you store the information you gather in analysis? I stick
them back into the tree or put them into (symbol-)tables. If you do so
as well: What do you do if the tree data in tables has to be processed
in subsequent tree transformation steps? How do you pass in the data?
2010/1/25 Loring Craymer <lgcraymer at yahoo.com>:
> Some key points:
> 1.) Capture semantics rather than designing tree structures.
> 2.) Preserve grammar structure--that is, rule a in pass n becomes rule a in pass n+1 unless there is reason to do otherwise.
> 3.) Avoid cluttering your grammars with action code.
> 4.) Separate analysis passes from transformation passes.
> Follow those principles, and you'll find that rippling changes across grammars is tedious, but not a real problem.
> ----- Original Message ----
>> From: Oliver Zeigermann <oliver.zeigermann at gmail.com>
>> To: antlr-interest Interest <antlr-interest at antlr.org>
>> Sent: Sun, January 24, 2010 1:03:35 AM
>> Subject: [antlr-interest] Anyone in the whole world doing multi step tree transformation?
>> I was just wondering if anyone except me is actually doing tree
>> transformations using ANTLR. I use the tree transformation feature
>> introduced in 3.1. While this does work well, it is so very hard to
>> refactor or extend my tree structures as I have to change all my
>> transformer stages and have no tool support to find out what to change
>> and where.
>> I started using heterogenous tokens with normalized children to make
>> use of compiler type checking which helps, but does not comletely
>> solve my issues as I still have an unchecked children list - which I
>> need to traverse the tree using tree walkes.
>> I was considering skipping the whole grammar driving tree
>> transformation step, but what should I replace it with?
>> I know of the xtext approach that uses non normalized heterogenous
>> tokens generated from a common model shared by all transformation
>> parts. Which seems like a good idea, however, does not seem to have a
>> means powerful enough to do serious tree transformation.
>> Any experiences? Hints?
>> Thanks in advance
>> - Oliver
>> List: http://www.antlr.org/mailman/listinfo/antlr-interest
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