[antlr-interest] tree parser example PDF docs and ANTLR Patte rns (was Re: the tree parser exampl)

[Terence Parr]

On Tuesday, May 7, 2002, at 04:41  PM, lgcraymer wrote:

> --- In antlr-interest at y..., mzukowski at y... wrote:
>> Antlr also does have some tree matching routines built in.  See the
>> implementations of the methods below in antlr.BaseAST
>>     public boolean equals(AST t);
>>     public boolean equalsList(AST t);
>>     public boolean equalsListPartial(AST t);
>>     public boolean equalsTree(AST t);
>>     public boolean equalsTreePartial(AST t);
>>     public ASTEnumeration findAll(AST tree);
>>     public ASTEnumeration findAllPartial(AST subtree);
>>
>> I've not needed these for my projects but would be interested in
> hearing how
>> people use them.
>>
>
> These are actually translations of SORCERER match utilities.  I'd be
> surprised if they are in active use: if I remember correctly, Ter used
> them in some of the early SORCERER examples, but they became unused as
> SORCERER matured.  After Gary Funck finished hammering on SORCERER, it
> was a pretty decent tool.  I was surprised to encounter them in ANTLR
> 2.
>
> For the findAll and findAllPartial methods to be very useful for
> rewriting, they would need to return pointers to parents or left
> siblings of the matched trees so that references could be patched.

Yeah, there was a tree "scanf" routine in old days that returned 
pointers to various nodes like this:

tscant("#(DOT %1:ID %2:ID)", &a, &b);

that would set pointers a and b for you :)  Handy.  It was kinda like 
SORCERER interpreted.

Ter
--
Co-founder, http://www.jguru.com
Creator, ANTLR Parser Generator: http://www.antlr.org


 

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