[ANN] parslet 1.4.0

parslet is a Parsing Expression Grammar based[1] parser library. Uff.
Now that is out of our system, here goes what it really does: It makes
writing parsers pleasant for the rest of us. No code generation, clear
access to data, unit testable.

* http://kschiess.github.com/parslet/index.html
* https://github.com/kschiess/parslet

Installation:

gem install parslet

Synopsis:

    require 'parslet'
    class Mini < Parslet::Parser
      rule(:integer) { match('[0-9]').repeat(1) }
      root(:integer)
    end

    Mini.new.parse("132432") # => "132432"@0

Changes:

We're continuing our tradition of aggressively curating the code to
better suit our needs:

+ Revised documentation. A few new API features have finally made it
into the documentation. Examples in the documentation are now curated
and run against the current code so that they really really work.

+ Optimistic parse: Parsing is two phase, with the first phase assuming
there will be no errors. This yields ~ 20% speed improvement in the case 
where the parse succeeds. Also, internal error handling is now using 
tuples. This and other optimizations have yielded ~ 30% overall
improvement. In SPEED!

+ Parslet::Source now doesn't hold a StringIO, it directly holds the
buffer to be parsed. Also: custom sources can be passed into a parse.

+ :reporter argument to parse, allowing to customize error reporting
within wide boundaries. See issue #64 for a discussion. Included are two 
error reporters, one (default) with the existing error tree
functionality, one reporting deepest errors as defined by the above
ticket. See http://kschiess.github.com/parslet/tricks.html for a
description of the reporter engines or run 'examples/nested_errors.rb'
and 'examples/deepest_errors.rb' to compare the methods.

! #error_tree and #cause removed from all of parslet. The
Parslet::ParseFailed exception now contains a #cause field that can be
asked for an #ascii_tree as before. Cleaner internal error handling, not 
stateful in atoms anymore. Some  parsers will see correct error
reporting for the first time. (issue #65) For this feature, we were able 
to delete a lot of code, something we're quite fond of.

- VM engine removed.

Special thanks go to John Mettraux who shook up existing structures just 
enough for them to fall into place better. Run. Write a language today.

[1] http://en.wikipedia.org/wiki/Parsing_expression_grammar