add assoc

src/experimental/_impl/_assoc_impl.scad

@@ -0,0 +1,14 @@
+use <util/slice.scad>;
+
+function _assoc_get(array, key) = 
+    let(idx = search([key], array)[0])
+    array[idx][1];
+
+function _assoc_put(array, key, value) =
+    let(idx = search([key], array)[0])
+    idx == [] ? concat(array, [[key, value]]) : 
+                concat(slice(array, 0, idx), [[key, value]], slice(array, idx + 1));
+
+function _assoc_remove(array, key) =
+    let(idx = search([key], array)[0])
+    idx == [] ? array : concat(slice(array, 0, idx), slice(array, idx + 1));

src/experimental/assoc.scad

@@ -0,0 +1,9 @@
+use <experimental/_impl/_assoc_impl.scad>;
+
+// treat an associative array as a dictionary.
+
+function assoc(array, cmd, key, value) =
+    is_undef(array) ? [] :
+    cmd == "put" ? _assoc_put(array, key, value) :
+    cmd == "get" ? _assoc_get(array, key) :
+    cmd == "remove" ? _assoc_remove(array, key) : assert("Uknown command");