initial commit w/ failing specs

README.rdoc

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+Some syntax transformation excercises in scheme.  Just seeing what's possible with macros, etc.

syntax_transformer.ss

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+#lang scheme/base
+
+(define list-contains-char?
+  (lambda (lst search)
+    (cond
+     ((null? lst) #f)
+     ((equal? (car lst) search) #t)
+     (else
+      (list-contains-char? (cdr lst)
+                           search)))))
+
+(define string->split
+  (lambda (str token)
+    (let ((chars (string->list str)))
+      (letrec
+          ((f (lambda (before after)
+                (cond
+                 ((null? after)
+                  (list before after))
+                 ((equal? (car after) token)
+                  (list before
+                        (cdr after)))
+                 (else
+                  (f (cons (car after)
+                           before)
+                     (cdr after)))))))
+        (let ((x (f '() chars)))
+          (list
+           (list->string (reverse (car x)))
+           (cdr x)))))))
+
+(define split_obj_and_args
+  (lambda (obj_and_args)
+    (string->split obj_and_args #\.)))
+
+(define transform-syntax
+  (lambda (syntax)
+    (cond
+     ((list-contains-char? (string->list (symbol->string (car syntax)))
+                           #\.)
+      (let ((sym_and_args (split_obj_and_args (symbol->string (car syntax)))))
+
+        (cons
+         (quote __message_send__)
+         (cons
+          (string->symbol (car sym_and_args))
+          (cons
+           (cdr sym_and_args)
+           '())))))
+     (else
+      syntax))))
+
+(provide transform-syntax)

syntax_transformer_test.ss

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+#!/usr/bin/env mzscheme
+#lang scheme/base
+
+(require (planet schematics/schemeunit:3)
+         "syntax_transformer.ss")
+
+; test the framework
+(check-equal? #t #t "true is true")
+
+(check-equal? 
+ (transform-syntax (quote (foo bar baz))) 
+ (quote (foo bar baz)))
+
+(check-equal? 
+ (transform-syntax (quote (foo.bar))) 
+ (quote (__message_send__ foo (quote bar))))
+
+(check-equal? 
+ (transform-syntax (quote (bar.baz))) 
+ (quote (__message_send__ bar (quote baz))))