[antlr-interest] TreeWalker to optimize AST under certain conditions

Tilman Bender tbender at stud.hs-heilbronn.de
Wed Apr 1 09:48:12 PDT 2009


Hi everybody,

I am trying to make a simple compiler for a language that does simple  
arithmetic expression and read/write operations.
I have a parser generating an AST. Now I would like to walk that AST  
an alter/rewrite it by removing superflous subtrees.

e.g:
When I get a subtree for an addition saying:
^(ADD 0 expr ) or ^(ADD expr 0) the subtree should be replaced by just  
expr

The same applies to multiplications with one or zero: remove the  
subtree and replace it by one of the operands or zero.

How could I achieve this with a tree-grammar?

kind regards

Tilman Bender
Student des Software Engineering
Hochschule Heilbronn
tbender at stud.hs-heilbronn.de



-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.antlr.org/pipermail/antlr-interest/attachments/20090401/74958a52/attachment.html 


More information about the antlr-interest mailing list