[antlr-interest] implemented your suggestion for AST factory

[Terence Parr]

Loring,

Re: hetero tree mapping (Java mode)...

I have altered the Java code generator so that it generates a call to a 
new ASTFactory(Hashtable) ctor.  The generated parser has this:

         protected void buildTokenTypeASTClassMap() {
                 tokenTypeToASTClassMap = new Hashtable();
                 tokenTypeToASTClassMap.put(new Integer(ID), 
IDNode.class);
                 ...
         };

then does this in the parser ctor:

   buildTokenTypeASTClassMap();
   astFactory = new ASTFactory(getTokenTypeToASTClassMap());

The TreeParser stuff I left alone as you can get the AST factory out of 
the parser and set in the TreeParser manually upon its creation if you 
are doing tree transforms.  I don't want 
duplicate-possibly-slightly-different copies of the mapping running 
around.

All seems backward compatible.  The Hashtable mapping is there for your 
homegrown ASTFactory if you want it via Parser method:

	/** If the user specifies a tokens{} section with heterogeneous
	 *  AST node types, then ANTLR generates code to fill
	 *  this mapping.
	 */
	public Hashtable getTokenTypeToASTClassMap() {
		return tokenTypeToASTClassMap;
	}

Oh, I fixed that problem where I was initializing a node during dup 
from the text not the ast.

Ter
--
Co-founder, http://www.jguru.com
Creator, ANTLR Parser Generator: http://www.antlr.org
Lecturer in Comp. Sci., University of San Francisco


 

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