PsiTermBuilder.html

PsiTermBuilder.java

// FILE. . . . . /home/hak/hlt/src/hlt/osfv1/apps/v1/sources/PsiTermBuilder.java
// EDIT BY . . . Hassan Ait-Kaci
// ON MACHINE. . Hak-Laptop
// STARTED ON. . Wed Sep 11 14:16:17 2013

// Last modified on Fri Sep 13 09:40:06 2013 by hak

Using the given hash set of tags already associated to previously constructed ψ-terms, this builds an uninterpreted ψ-term structure out of the syntactic parts given as arguments.

N.B. This (and merge and prettyPrint of PsiTerm) does not seem to work properly. The problem has to do with how dereferencing alters sub-structures while they are being built (or visited). The alternative approach would be to keep the raw psiterm structure built by the parser and compile it directly rather than trying to do this partial evaluation. Execution of the compiled code should then result in a buildable (and printable) structure.


PsiTerm buildPsiTerm (HashSet tags, Tag tag, SortExpression sort, Stack keys, Stack subterms)
{
  tag = tag.deref();	// dereference the tag to get to the correct one if needed
  
  PsiTerm pst = null;		// this is the new psiterm to build and return
  PsiTerm previous = null;	// this is a previously existing psiterm

  // if the tag is a reoccurring tag
  if (tags.contains(tag))	
    {
      // build this term with a newly generated tag:
      pst = buildPsiTerm(tags,
			 Tag.newTag(),
			 sort,
			 keys,
			 subterms).deref();
      // retrieve the tag's term, marking the tag as shared (due to the reoccurrence):
      previous = tag.deref().markAsShared().term();
      // merge the newer term into the previous one and return it:
      previous.merge(pst);
      return previous.deref();
    }

  // the tag has not occurred before:
  pst = new PsiTerm(tag).setSort(sort);	// construct a new psiterm with the given tag and sort
  tags.add(tag);			// and add the tag to the tag occurrences

  // build the subterms if there are any:
  if (subterms != null) // then keys != null as well
    while (!subterms.empty())
      {
	// get the current raw subterm to build:
	RawPsiTerm sub = (RawPsiTerm)subterms.pop();
	// build the current subterm
	PsiTerm subterm = buildPsiTerm(tags,
				       Tag.getTag(sub.tag),
				       sub.sort,
				       sub.keys,
				       sub.subterms).deref();

	System.out.println("    >>> built subterm: \n        "+subterm.displayForm(8));

	// get the current subterm's key
	Object key = keys.pop();

	if (key == null)
	  // this is an implicitly contiguous position
	  {
	    // retrieve the dereferenced possibly existing subterm:
	    previous = pst.getNextContiguousPositionSubterm();
	    if (previous == null)
	      pst.addContiguousPositionSubterm(subterm);
	    else
	      previous.merge(subterm.deref());

	    continue;
	  }

	if (key instanceof Integer)
	  // this is an explicitly specified position
	  {
	    int position = ((Integer)key).intValue();
	    previous = pst.getSubterm(position);
	    if (previous == null)
	      pst.setSubterm(position,subterm);
	    else
	      previous.merge(subterm.deref());

	    continue;
	  }

	// this is a feature subterm
	Feature feature = Feature.getFeature((String)key);

	previous = pst.getSubterm(feature);
	if (previous == null)
	  pst.setSubterm(feature,subterm);
	else
	  previous.merge(subterm.deref());
      }
  
  return pst.deref();    
}

This file was generated on Fri Sep 13 10:40:22 CEST 2013 from file PsiTermBuilder.java
by the hlt.language.tools.Hilite Java tool written by Hassan Aït-Kaci