|Tools| <Jax: Scanner Generator| |Up to Tools| |Jinstall: Self installing archiver >

Tools Jell: Parser Generator


3 Jell: Parser Generator

Jell is a parser generator that generates recursive descent parsers from LL(1) grammars. You can also embed extra directives to get past any of that tricky non LL(1) stuff. Now why might you want to consider a LL(1) generator over more powerful LALR recognizers?

In practice, LL(1) grammars seem to cover most portions of languages, and recursive parsers are usually easier to debug than wading through the state transitions of an LALR parser. L-attributed definitions are naturally added to the parser, and dont cause the occasional weird conflicts that an LALR parser generates when adding semantic actions. The icing on jell's particular cake is that you can define rules in a convenient extended BNF format, and you get a degree of error report and repair for free.

Other parsers generators which I know exist for Java are *JavaCUP, a very nice LALR parser and *jb, a tcl script which postprocesses bison output and converts it to Java.

Jell is alpha code, and all I know for sure is that its parser can bootstrap itself identically. If you mail me bug reports, I'll fix them as quick as I can. Jell is freely available with source, and can be used/modified/sold/processed for llama fodder with absolutely no restrictions -- just add a note saying where you got it from.



|Tools| <Jax: Scanner Generator| |Up to Tools| |Jinstall: Self installing archiver >

KB Sriram
Comments, bug reports: kbs@sbktech.org

Revised: Thu Aug 1 18:12:33 1996
URL: http://www.sbktech.org/jell.html