add couple list utils

list-split and list-join

tests/run.scm

@@ -9,6 +9,7 @@
 
 (include "basic.scm")
 (include "semen.scm")
+(include "utils.scm")
 
 ;;; Should be the last in the test suite
 (test-exit)

tests/utils.scm

@@ -0,0 +1,22 @@
+(test-group "utils"
+
+  (test
+   '((1) (2) (3))
+   (list-split '(1 * 2 * 3) '*))
+
+  (test
+   '((1 2 3))
+   (list-split '(1 2 3) '*))
+
+  (test
+   '(() (1) (2) (3) ())
+   (list-split '(* 1 * 2 * 3 *) '*))
+
+  (test
+   '((const) (const struct something))
+   (list-split '(const * const struct something) '*))
+
+  (test
+   '(1 * 2 * 3)
+   (list-join '(1 2 3) '*))
+)

utils.scm

@@ -4,7 +4,8 @@
 
 (import
   (chicken pathname)
-  (chicken process-context))
+  (chicken process-context)
+  srfi-1)
 
 (define (get-env-var name)
   (get-environment-variable name))
@@ -17,3 +18,21 @@
         (make-absolute-pathname
          (current-directory)
          (pathname-directory file))))))
+
+(define (list-split src-list split-elt)
+  ;; split '(1 2 / 3 4 / 5 6) by '/ -> '((1 2) (3 4) (5 6))
+  (fold (lambda (elt acc)
+          (if (eq? elt split-elt)
+              (append acc (list (list)))
+              (append (drop-right acc 1)
+                      (list (append (last acc) (list elt))))))
+        (list (list))
+        src-list))
+
+(define (list-join lists join-by)
+  (drop-right
+   (fold (lambda (elt acc)
+           (append acc (list elt) (list join-by)))
+         (list)
+         lists)
+   1))