modularize sex

macros.scm

@@ -0,0 +1,45 @@
+(module macros
+    (register-macro
+     cat
+     get-macro
+     macro?
+     apply-macro
+     defmacro)
+  (import
+    scheme
+    (only fmt fmt)
+    (chicken base)
+    (chicken plist)
+    (chicken string))
+
+  (define (cat-syms s-1 s-2)
+    (fmt #f s-1 s-2))
+
+  (define (cat sym-1 sym-2)
+    (string->symbol (cat-syms sym-1 sym-2)))
+
+  (define (register-macro name arglist body)
+    (put! name 'sex-macro
+          `(lambda ,arglist
+             (import scheme
+                     (only macros cat))
+             ,@body)))
+
+  (define (get-macro name)
+    (eval (get name 'sex-macro)))
+
+  (define (macro? form)
+    (and (list? form)
+         (symbol? (car form))
+         (get (car form) 'sex-macro)))
+
+  (define (apply-macro form)
+    (assert (macro? form)
+            (fmt #f (car form) " is not a macro"))
+    (apply (get-macro (car form))
+           (cdr form)))
+
+  (define (defmacro form)
+    (let ((arglist (car form))
+          (body (cdr form)))
+      (register-macro (car arglist) (cdr arglist) body))))