From 9c447a384a5dc6f3de7cb314ca16f9c784defd45 Mon Sep 17 00:00:00 2001
From: Justin Ethier <justin.ethier@gmail.com>
Date: Thu, 6 Aug 2015 22:03:54 -0400
Subject: [PATCH] WIP - macros

---
 scheme/cyclone/macros.sld | 19 ++++++++++++++
 test2.scm                 | 55 ++++++++++++++++++++-------------------
 2 files changed, 47 insertions(+), 27 deletions(-)

diff --git a/scheme/cyclone/macros.sld b/scheme/cyclone/macros.sld
index 4a2fcf95..a1dc40d6 100644
--- a/scheme/cyclone/macros.sld
+++ b/scheme/cyclone/macros.sld
@@ -4,6 +4,8 @@
   ; TODO: really need export-all for these cyclone libs!!
   (export
     define-syntax?
+    macro?
+    macro-expand
   )
   (begin
     ;; Macro section
@@ -11,6 +13,23 @@
     (define (define-syntax? exp)
       (tagged-list? 'define-syntax exp))
 
+    (define (macro? exp defined-macros) (assoc (car exp) defined-macros))
+    (define (macro-expand exp defined-macros)
+      (let ((macro (assoc (car exp) defined-macros)))
+        ;; assumes ER macro
+        (if macro
+          ((cdr macro) 
+            ;exp 
+            ; could be a raw lambda, if that is the case try quoting it
+            (if (procedure? (cdr macro))
+              exp
+              (list 'quote exp))
+            (lambda (sym) ;; TODO: not good enough, need to actually rename, and keep same results if
+              sym)        ;; the same symbol is renamed more than once
+            (lambda (sym-a sym-b) ;; TODO: the compare function from exrename.
+              (eq? sym-a sym-b))) ;; this may need to be more sophisticated
+          exp))) ;; TODO: error instead??
+
     ; TODO: get macro name, transformer
     ; TODO: base off of syntactic closures instead of ER macros??
     ; TODO: let-syntax forms
diff --git a/test2.scm b/test2.scm
index d066bf1c..04cf1b28 100644
--- a/test2.scm
+++ b/test2.scm
@@ -1,30 +1,31 @@
-(import (scheme eval))
-
-(eval '((lambda (expr rename compare) (cond ((null? (cdr expr))) ((null? (cddr expr)) (cadr expr)) (else (list (rename (quote if)) (cadr expr) (cons (rename (quote and)) (cddr expr)) #f)))) (test 1 2 3) (lambda (x) x) '()))
-;(eval '((lambda (x) x) 1))
-
-
-;(import (scheme base)
-;        (scheme write))
+;(import (scheme eval) (scheme write))
 ;
-;;(define-syntax test
-;;  (er-macro-transformer
-;;    (lambda (expr rename compare)
-;;      `((lambda ()
-;;        (write "testing")
-;;        (write (quote ,(cdr expr))))))))
-;;
-;; WTF is the macro unable to be evaluated when the same code works as part of *defined-macros*???
-;;
-;(define-syntax test 
+;(eval '((lambda (expr rename compare) (cond ((null? (cdr expr)) #t) ((null? (cddr expr)) (cadr expr)) (else (list (rename (quote if)) (cadr expr) (cons (rename (quote and)) (cddr expr)) #f)))) '(test 1 2 3) (lambda (x) x) '()))
+;;;(eval '((lambda (x) x) 1))
+;
+;
+(import (scheme base)
+        (scheme write))
+
+;(define-syntax test
 ;  (er-macro-transformer
-;     (lambda (expr rename compare)
-;       (cond ((null? (cdr expr)))
-;             ((null? (cddr expr)) (cadr expr))
-;             (else (list (rename 'if) (cadr expr)
-;                         (cons (rename 'and) (cddr expr))
-;                         #f))))))
+;    (lambda (expr rename compare)
+;      `((lambda ()
+;        (write "testing")
+;        (write (quote ,(cdr expr))))))))
 ;
-;(test 1 2 3)
-;;(test 'done)
-;'done
+; WTF is the macro unable to be evaluated when the same code works as part of *defined-macros*???
+;
+(define-syntax test 
+  (er-macro-transformer
+     (lambda (expr rename compare)
+       (cond ((null? (cdr expr)) #t)
+;       (cond ((null? (cdr expr)))
+             ((null? (cddr expr)) (cadr expr))
+             (else (list (rename 'if) (cadr expr)
+                         (cons (rename 'and) (cddr expr))
+                         #f))))))
+
+(test 1 2 3)
+;(test 'done)
+'done