Add string utility functions

anarres/strings.scm

@@ -0,0 +1,11 @@
+(define-module (anarres strings))
+
+(define-public (string-remove-prefix prefix s)
+  (if (string-prefix? prefix s)
+      (string-drop s (string-length prefix))
+      s))
+
+(define-public (string-remove-suffix suffix s)
+  (if (string-suffix? suffix s)
+      (string-drop-right s (string-length suffix))
+      s))