add count

src/experimental/note.md

@@ -12,3 +12,4 @@ new:
 - polyline_join: doc multi-childs
 - mz_squarewalls, mz_hexwalls
 - mz_hamiltonian supports init_cells
+- util/count

src/util/count.scad

@@ -0,0 +1 @@
+function count(lt, test) = len([for(elem = lt) if(test(elem)) undef]);

test/test_all.scad

@@ -75,6 +75,7 @@ include <util/test_every.scad>;
 include <util/test_shuffle.scad>;
 include <util/test_find_index.scad>;
 include <util/test_spherical_coordinate.scad>;
+include <util/test_count.scad>;
 include <util/set/test_hashset.scad>;
 include <util/map/test_hashmap.scad>;
 

test/util/test_count.scad

@@ -0,0 +1,10 @@
+use <util/count.scad>;
+
+module test_count() {
+    echo("==== test_count ====");
+
+    points = [[7, 2, 2], [1, 1, 2], [3, 4, 2], [3, 4, 2], [1, 2, 3]];
+    assert(count(points, function(p) norm(p) > 5) == 3);
+}
+
+test_count();