Convert multi-LETREC to internal definitions in stream.scm.

diff --git a/src/runtime/stream.scm b/src/runtime/stream.scm
index 8da5bbf86c9064e293fe8dff1836b3e49e3454da..6e1ef29a46b1d2bbdeb993f396204e1ec3a44187 100644 (file)
--- a/src/runtime/stream.scm
+++ b/src/runtime/stream.scm
@@ -274,32 +274,27 @@ USA.
 (define prime-numbers-stream)
 
 (define (make-prime-numbers-stream)
-  (cons-stream
-   2
-   (letrec
-       ((primes (cons-stream 3 (fixnum-filter 5)))
-       (fixnum-filter
-        (let ((limit (fix:- (fix:largest-value) 2)))
-          (lambda (n)
-            (if (fix:<= n limit)
-                (let loop ((ps primes))
-                  (cond ((fix:< n (fix:* (car ps) (car ps)))
-                         (cons-stream n (fixnum-filter (fix:+ n 2))))
-                        ((fix:= 0 (fix:remainder n (car ps)))
-                         (fixnum-filter (fix:+ n 2)))
-                        (else
-                         (loop (force (cdr ps))))))
-                (generic-filter n)))))
-       (generic-filter
-        (lambda (n)
-          (let loop ((ps primes))
-            (cond ((< n (square (car ps)))
-                   (cons-stream n (generic-filter (+ n 2))))
-                  ((= 0 (remainder n (car ps)))
-                   (generic-filter (+ n 2)))
-                  (else
-                   (loop (force (cdr ps)))))))))
-     primes)))
+  (let ((limit (fix:- (fix:largest-value) 2)))
+    (define odd-primes (cons-stream 3 (fixnum-filter 5)))
+    (define (fixnum-filter n)
+      (if (fix:<= n limit)
+         (let loop ((ps odd-primes))
+           (cond ((fix:< n (fix:* (car ps) (car ps)))
+                  (cons-stream n (fixnum-filter (fix:+ n 2))))
+                 ((fix:= 0 (fix:remainder n (car ps)))
+                  (fixnum-filter (fix:+ n 2)))
+                 (else
+                  (loop (force (cdr ps))))))
+         (generic-filter n)))
+    (define (generic-filter n)
+      (let loop ((ps odd-primes))
+       (cond ((< n (square (car ps)))
+              (cons-stream n (generic-filter (+ n 2))))
+             ((= 0 (remainder n (car ps)))
+              (generic-filter (+ n 2)))
+             (else
+              (loop (force (cdr ps)))))))
+    (cons-stream 2 odd-primes)))
 
 (define (initialize-package!)
   (let ((reset-primes!