After almost a year, I am proud to present IronScheme 1.0 beta 1.

Release notes & Download

Have fun

IronScheme is now open to the public . You can get more details @ IronScheme on Codeplex, the current source code is available via the source repository on Codeplex.

IronScheme replaces IronLisp, and has been a partial rewrite IronLisp. Currently IronScheme is at the same functional level where IronLisp left off, excluding support for .NET interop currently. The main focus is R5RS compliance (well as far as I can get to it).

Currently, the most significant part that lacks for R5RS compliance is a decent number system. It only supports ‘double’ and ‘int32′ for now, but I plan to support the entire number tower, if possible.

There also has been some improvements, especially the interactive console, and the ‘extensibility’ model of IronScheme. Tab completion is now available on the console, as well as pretty colors for errors, evaluation result, etc.

This is so yummy, I thought I would share it; I just love the way this works:

; tests for define-syntax
(define-syntax begin
  (syntax-rules ()
    ((_ exp ...)
     ((lambda () exp ...)))))

(define-syntax for
  (syntax-rules (in into)
    ((_ a in b f ...)
     (for-each (lambda (a) (begin f ...)) b)) ;nested begin
    ((_ a b f)
     (for-each (lambda (a) f) b))
    ((_ a into b f ...)
     (for-each (lambda (a) f ...) b))))

(for c in "hello"
  (begin
    (display (char-upcase c))))

(newline)

(for c into "hello"
  (display (char-upcase c)))

(newline)

(for c "hello"
  (display (char-upcase c)))

(newline)

; error check
(for c out-of "hello"
  (display (char-upcase c)))

(for c "hello"
  (display (char-upcase c))
  (display (char-downcase c)))

Seems they cant stop making breaking changes

They seemed to have changed their whole ‘casting’ system. Previously I had work around valuetypes being passed by address! Hence using the object type in the assembly, but tracking the real type during compilation. Now I will have to rethink the system…

Thanks to Macro by example, it pointed out some very ‘deep’ corner cases, as I dont even really understand the code so well! Also pointed out some bugs

Also implemented is the ‘=>’ keyword for ‘cond’ and ‘case’ is implemented now too. These 2 were needed to basically use ‘Macro by example’, unaltered.

On a further note, there seems to be a R4RS test ’suite’, that I can hopefully use soon to implement most of the tests

[edit] So it seems it was not working correctly at all I have now gone thru it and fixed this issues [edit]

I have uploaded a PDF containing the current progress towards R5RS. I will try to keep the version on this site current.

IronLisp progress

http://www.chiark.greenend.org.uk/~sgtatham/bugs.html

define-syntax
let-syntax
letrec-syntax
syntax-case

Lots of info and examples
Chez Sheme macros
Scheme FAQ: Macros
Old, but the appendix is quite descriptive

How fold and friends work

Sorry for all the hiccups, I have tested the repository now from a remote location. All files are up2date now, and works.