feat: nil/null/empty/blank literals, resolves #102

src/drop/icomparable.ts

@@ -0,0 +1,13 @@
+import { isFunction } from 'src/util/underscore'
+
+export interface IComparable {
+  equals: (rhs: any) => boolean
+  gt: (rhs: any) => boolean
+  geq: (rhs: any) => boolean
+  lt: (rhs: any) => boolean
+  leq: (rhs: any) => boolean
+}
+
+export function isComparable (arg: any): arg is IComparable {
+  return arg && isFunction(arg.equals)
+}