1 files changed, 5 insertions, 0 deletions
diff --git a/src/common.lisp b/src/common.lisp
index 2c56184..c9e6e8b 100644
--- a/src/common.lisp
+++ b/src/common.lisp
@@ -15,3 +15,8 @@
 (defun trim (input)
   (string-trim '(#\Space #\Newline #\Backspace #\Tab
                  #\Linefeed #\Page #\Return #\Rubout) input))
+
+(defun fold-left (reducer initial list)
+  (loop for fold = initial then (funcall reducer fold element)
+        for element in list
+        finally (return fold)))