Option to generate abstract classes

[sharwell]

For lexers and parsers which have an inherent requirement to implement some features in a derived class, it would be convenient to be able to generate the lexer/parser classes as abstract. This would also allow abstract methods instead of stubs which throw UnsupportedOperationException to be placed in the @members{} blocks.

In addition, it would be especially useful if it prepended Abstract to the name of the class generated for an abstract parser grammar FooParser:

• AbstractFooParser
• FooParserParseListener / FooParserListener / FooParserVisitor
• FooParserBaseParseListener / FooParserBaseListener / FooParserBaseVisitor

[parrt]

yeah, we need cmd-line options like -package, -superclass, -abstract-parser

[sharwell]

Two other issues cover the -package and -superclass options.