This page contains release notes and known issues for the old versions of JTB, as well as features we had planned to implement in newer versions.  The release notes for the current version may be obtained here.

Release Notes for JTB 1.1.2

• Fixed bug where node class constructors didn't check if their arguments were null before trying to call setParent() on them.  This made manual creation of syntax trees problematic if certain parts of the tree were to be left empty.
• By default, JTB no longer generates parent references into node classes.  Use the new -pp parameter to generate them.
• Added -f parameter for JTB to generate descriptive node class field names such as whileStatement and nodeList1 rather than names like f1 and f2.
• Added -ns parameter to allow user to specify a superclass for all node classes.  This class must be supplied by the user.
• Added a new constructor to all node classes which fills in all unchanging tokens such as < PLUS: "+" > or < CLASS: "class" > with the proper NodeToken to aid in manual syntax tree construction.

Known Issues for JTB 1.1.2

• JavaCC reserved words (such as EOF, JAVACODE, TOKEN, etc.) cannot be used as identifiers in Java code sections of a JTB input file.  This includes Java blocks, Javacode productions, and between the PARSER_BEGIN and PARSER_END keywords of a grammar file.
• Fixing this bug will involve numerous changes to the JTB grammar (and thus, the visitors as well).  This is likely to introduce bugs into JTB.  Since the effort to fix the bug is so much greater than the potential benefit of the bug fix, this bug will probably not be fixed.
• Workaround: don't use these tokens as identifiers.
• JAVACODE productions cause JTB to produce erroneous output.
• JTB will attempt to put JAVACODE productions in the tree, even if the production is of return type void.  For example:

JAVACODE

void skip_to_matching_braces() {

   // Code to eat tokens until a matching brace is found

}



void NT() : { }

{

   A() skip_to_matching_braces()

}

This will cause JTB to attempt to construct a node of type NT with children of type A and skip_to_matching_braces,which is incorrect.
• Workaround steps:
1. Make a "dummy" class with the name of your JAVACODE production.  You can copy one of the classes in the syntaxtree directory and remove all the child references.
2. Change the return value of the JAVACODE production to the name of the production.
3. Add something along the lines of

return new your_production_name();

at the end of the Java code.

Planned Features

We are investigating the idea of visitor templates which allow you to set the return types and parameters of visit() methods.

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