* Added let-syntax and letrec-syntax.

R6RS-TODO.txt

@@ -9,7 +9,6 @@ TODO for (R6RS BASE)
   - library phases (simply ignore)
   - internal imports
   - Recognize (define x)
-  - Add let-syntax and letrec-syntax
   - Add identifier-syntax
   - Add do, let*-values.
 
@@ -86,4 +85,5 @@ TODO for (R6RS BASE)
 
 
 Completed for (R6RS BASE):
+  - Add let-syntax and letrec-syntax
     numerator           denominator

src/ikarus.main.ss

@@ -6,11 +6,10 @@
 (library (ikarus greeting)
   (export print-greeting)
   (import (ikarus))
-  (define (print-greeting)
-    (define-syntax compile-time-string
-      (lambda (x) (date-string)))
-    (printf "Ikarus Scheme (Build ~a)\n" (compile-time-string))
-    (display "Copyright (c) 2006-2007 Abdulaziz Ghuloum\n\n")))
+  (letrec-syntax ([compile-time-string (lambda (x) (date-string))])
+    (define (print-greeting)
+      (printf "Ikarus Scheme (Build ~a)\n" (compile-time-string))
+      (display "Copyright (c) 2006-2007 Abdulaziz Ghuloum\n\n"))))
 
 
 ;;; Finally, we're ready to evaluate the files and enter the cafe.

src/ikarus.syntax.ss

@@ -426,7 +426,8 @@
                       [type (binding-type b)])
                  (case type
                    [(define define-syntax core-macro begin macro
-                      local-macro global-macro module set!)
+                      local-macro global-macro module set!
+                      let-syntax letrec-syntax)
                     (values type (binding-value b) id)]
                    [else
                     (values 'call #f #f)]))
@@ -1625,6 +1626,24 @@
              [(_ x x* ...)
               (build-sequence no-source
                 (chi-expr* (cons x x*) r mr))])]
+          [(let-syntax letrec-syntax)
+           (syntax-match e ()
+             [(_ ([xlhs* xrhs*] ...) xbody xbody* ...)
+              (unless (valid-bound-ids? xlhs*) 
+                (stx-error e "duplicate identifiers"))
+              (let* ([xlab* (map gen-label xlhs*)]
+                     [xrib (make-full-rib xlhs* xlab*)]
+                     [xb* (map (lambda (x) 
+                                (make-eval-transformer
+                                  (expand-transformer
+                                    (if (eq? type 'let-syntax) x (add-subst xrib x))
+                                    mr)))
+                              xrhs*)])
+                (build-sequence no-source
+                  (chi-expr* 
+                    (map (lambda (x) (add-subst xrib x)) (cons xbody xbody*))
+                    (append (map cons xlab* xb*) r)
+                    (append (map cons xlab* xb*) mr))))])]
           [(displaced-lexical)
            (stx-error e "identifier out of context")]
           [(syntax) (stx-error e "reference to pattern variable outside a syntax form")]
@@ -1809,6 +1828,24 @@
                           (chi-body* (cdr e*)
                              (cons (cons lab b) r) (cons (cons lab b) mr)
                              lex* rhs* mod** kwd* rib top?))))]
+                 [(let-syntax letrec-syntax)
+                  (syntax-match e ()
+                    [(_ ([xlhs* xrhs*] ...) xbody* ...)
+                     (unless (valid-bound-ids? xlhs*)
+                       (stx-error e "duplicate identifiers"))
+                     (let* ([xlab* (map gen-label xlhs*)]
+                            [xrib (make-full-rib xlhs* xlab*)]
+                            [xb* (map (lambda (x) 
+                                       (make-eval-transformer
+                                         (expand-transformer
+                                           (if (eq? type 'let-syntax) x (add-subst xrib x))
+                                           mr)))
+                                     xrhs*)])
+                       (chi-body* 
+                         (append (map (lambda (x) (add-subst xrib x)) xbody*) (cdr e*))
+                         (append (map cons xlab* xb*) r)
+                         (append (map cons xlab* xb*) mr)
+                         lex* rhs* mod** kwd* rib top?))])]
                  [(module)
                   (let-values ([(lex* rhs* m-exp-id* m-exp-lab* r mr mod** kwd*)
                                 (chi-internal-module e r mr lex* rhs* mod** kwd*)])

src/makefile.ss

@@ -78,6 +78,8 @@
     [module            (module)]
     [begin             (begin)]
     [set!              (set!)]
+    [let-syntax        (let-syntax)]
+    [letrec-syntax     (letrec-syntax)]
     [foreign-call      (core-macro . foreign-call)]
     [quote             (core-macro . quote)]
     [syntax-case       (core-macro . syntax-case)]
@@ -181,6 +183,8 @@
 (define ikarus-macros-map
   '([define           i r]
     [define-syntax    i r]
+    [let-syntax       i r]
+    [letrec-syntax    i r]
     [module           i cm]
     [begin            i r]
     [set!             i r]