Hi all,
I just released the 0.2.0 version of Heist, my Ruby Scheme runtime.
Changes
in this release include:
- Entirely revised to correctly support lists as linked pairs
- Complete set of R5RS list functions
- Syntax for dotted pairs and improper lists implemented
- Rest-args for functions using dot notation
- Almost-complete R5RS numeric library, including complexes and
rationals - Some parser bugs regarding literals and quoting fixed
- Many macro parsing and expansion bugs fixed, esp. concerning nested
repeating patterns - Macro keywords and collisions with local variables now follow the spec
- R6RS ellipsis escaping feature – (… …) – implemented
- All library syntax now implemented as macros, should all support
call/cc - Ruby data can now be executed as Scheme code
- Lots of inline documentation for the runtime
More information on GitHub and my blog:
http://blog.jcoglan.com/2009/04/02/april-fool-area-man-releases-worlds-slowest-scheme-interpreter/
Of particular interest to me is the Ruby-data-as-Scheme-code feature,
for
example:
scheme = Heist::Runtime.new
scheme.exec [:define, [:square, :x],
[:*, :x, :x]]
scheme.exec [:square, 9]
#=> 81
Once I’ve settled on a nice way to expose the macro system to Ruby, this
could be used with ParseTree to rewrite Ruby code, like raganwald’s
‘rewrite’ gem. Also, there’s a possibility for someone to write a new
Ruby
interpreter by taking ParseTree and adding a new set of built-in
functions
to the Heist runtime to execute its output. If someone has a serious
stab at
this I’d love to see the results.