Factored out common scheme code into modules

1 files changed, 26 insertions, 0 deletions

diff --git a/sieve/my-streams.scm b/sieve/my-streams.scm
new file mode 100644
index 0000000..6c08762
--- /dev/null
+++ b/sieve/my-streams.scm
@@ -0,0 +1,26 @@
+
+(library (my-streams)
+    (export stream-ordered-diff stream-merge)
+    (import (rnrs base) (srfi srfi-41))
+
+
+
+(define-stream (stream-ordered-diff xstrm ystrm)
+    (stream-match xstrm (() '()) ((x . xs)
+        (stream-match ystrm (() xstrm) ((y . ys)
+            (cond ((< x y) (stream-cons x (stream-ordered-diff xs ystrm)))
+                  ((> x y) (stream-ordered-diff xstrm ys))
+                  (else (stream-ordered-diff xs ys))))))))
+
+
+
+(define-stream (stream-merge xstrm ystrm)
+    (stream-match xstrm (() ystrm) ((x . xs)
+        (stream-match ystrm (() xstrm) ((y . ys)
+            (cond ((< x y) (stream-cons x (stream-merge xs ystrm)))
+                  ((> x y) (stream-cons y (stream-merge xstrm ys)))
+                  (else (stream-cons x (stream-merge xs ys)))))))))
+
+
+
+)