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-rw-r--r--sieve/my-streams.scm26
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diff --git a/sieve/my-streams.scm b/sieve/my-streams.scm
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+
+(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)))))))))
+
+
+
+)