Add a diff library.

I was hesitant to add a diff library, but it was surprisingly easy. A
straightforward application of dynamic programming.

1 files changed, 35 insertions, 0 deletions

diff --git a/csc/strings-test.csc b/csc/strings-test.csc
index 2e6d240..49f8d20 100644
--- a/csc/strings-test.csc
+++ b/csc/strings-test.csc
@@ -44,6 +44,30 @@
     (assert (not-found-error? got-exception))))
 
 
+(test contains
+  (assert-equal
+    #t
+    (contains "abc" "b")))
+
+
+(test doesnt-contain
+  (assert-equal
+    #f
+    (contains "abc" "d")))
+
+
+(test contains-empty
+  (assert-equal
+    #t
+    (contains "" "")))
+
+
+(test empty-contains
+  (assert-equal
+    #f
+    (contains "" "a")))
+
+
 (test join-,
   (assert-equal "a,b,c" (join "," "a" "b" "c")))
 
@@ -58,3 +82,14 @@
 
 (test join-empty
   (assert-equal "abc" (join "" "a" "b" "c")))
+
+
+(test split-empty
+  (assert-equal '("") (split "" " ")))
+
+(test split
+  (assert-equal '("a" "b") (split "a b" " ")))
+
+
+(test split-trailing-empty
+  (assert-equal '("a" "") (split "a " " ")))