OpenToken 4.0a released

OpenToken 4.0a released

[Stephen Leake]

I've released a new version of OpenToken; 4.0a

It will be in Debian Squeeze, and in Debian testing before that.

See http://www.stephe-leake.org/ada/opentoken.html to download source
and see full list of changes.

Major changes:

Lookahead and backtracking is supported in recursive descent parsers.
This can generate horribly inefficient parsers if you are not careful.

Fixed major bug in LALR parser generator related to which production
gets the accept action. This bug made many small grammars unworkable;
now they all work.

Syntax errors reported by LR and recursive descent parsers include the
list of expected tokens.

The examples have been improved to more clearly demonstrate the
differences and similarities between LR parsing and recursive descent
parsing with OpenToken.

There are new examples of recursive descent parsing, showing that
naive grammars can work, if inefficiently. 

The OpenToken.Token.List_Mixin, .Sequence_Mixin, .Selection_Mixin now
specify actions via procedure pointers at run-time, rather than via
overloaded procedures. This significantly simplifies specifying
recursive descent grammars.

Language_Lexers.HTML_Lexer supports the <pre> tag; the contents are
treated as a comment.

-- 
-- Stephe