[Grammatica-users] Question about grammatica

[MANSION, James, FM]

Hi

 

First, apologies about the standard mail gateway added stuff at the bottom.  I can't turn it off. :-(

 

Now - I'm trying to use grammatica analysis in two phases.  I'm using the Java API, version 1.4.

 

In the first, the value I return at values(0) is a type code, which I use in a sematic analysis pass.

Then, I perform an interpretive pass (and actually, I may repeat this) in which I evaluate my parse tree having set up mappings for 'external' data.

 

One of the side effects of my semantic analysis is that I save node references away for various bits of the parse tree, and for literal values I save them in a HashMap which is keyed by the Node.

 

I find that unfortunately the rewriting of the Production tree in an analyzer works against me because of coutrse the hashCode changes as a result of the tree rebuild.  In my case I can work around this because in practice I always have a terminal Token against which I can key the result.

 

When I found that exitProd returned a Node, I had assumed that if I wanted to do rewriting and restructuring, then that is where I would do it, and that rather than visit re-adding children, the driver would replace the children in-place in the child vector and then compress-out any nulls.  I would hope that a 'null' analysis for an interpreter pass would not perform any tree rewriting but would just visit nodes. :-(

 

I'n in two minds whether to attempt this, or have another method similar to analyze(Node,ParserLogException) that just visits the structure, without implicitly clearing values from any nodes, and ignoring returned Node references so that the structure is unchanged.

 

How do others handle this?

James Mansion

+44 20 7648 3972

 

 

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