1 files changed, 32 insertions, 0 deletions
diff --git a/jstests/libs/fun.js b/jstests/libs/fun.js
new file mode 100644
index 0000000..276f32a
--- /dev/null
+++ b/jstests/libs/fun.js
@@ -0,0 +1,32 @@
+// General high-order functions
+
+function forEach (action, array) {
+  for (var i = 0; i < array.length; i++)
+    action (array[i]);
+}
+
+function foldl (combine, base, array) {
+  for (var i = 0; i < array.length; i++)
+    base = combine (base, array[i]);
+  return base
+}
+
+function foldr (combine, base, array) {
+  for (var i = array.length - 1; i >= 0; i--)
+    base = combine (array[i], base);
+  return base
+}
+
+function map (func, array) {
+  var result = [];
+  for (var i = 0; i < array.length; i++)
+    result.push (func (array[i]));
+  return result
+}
+
+function filter (pred, array) {
+  var result = []
+  for (var i = 0; i < array.length; i++)
+    if (pred (array[i])) result.push (array[i]);
+  return result
+}