feat: at_least, at_most, sort_naturual for #132

src/builtin/filters/math.ts

@@ -1,5 +1,9 @@
+const toLowerCase = String.prototype.toLowerCase
+
 export default {
   'abs': (v: number) => Math.abs(v),
+  'at_least': (v: number, n: number) => Math.max(v, n),
+  'at_most': (v: number, n: number) => Math.min(v, n),
   'ceil': (v: number) => Math.ceil(v),
   'divided_by': (v: number, arg: number) => v / arg,
   'floor': (v: number) => Math.floor(v),
@@ -10,5 +14,26 @@ export default {
     return Math.round(v * amp) / amp
   },
   'plus': (v: number, arg: number) => Number(v) + Number(arg),
+  'sort_natural': sortNatural,
   'times': (v: number, arg: number) => v * arg
 }
+
+function caseInsensitiveCmp (a, b) {
+  if (!b) return -1
+  if (!a) return 1
+  a = toLowerCase.call(a)
+  b = toLowerCase.call(b)
+  if (a < b) return -1
+  if (a > b) return 1
+  return 0
+}
+
+function sortNatural (input: any[], property?: string) {
+  if (!input || !input.sort) return []
+  if (property !== undefined) {
+    return [...input].sort(
+      (lhs, rhs) => caseInsensitiveCmp(lhs[property], rhs[property])
+    )
+  }
+  return [...input].sort(caseInsensitiveCmp)
+}