add ref for grabbing a function

src/prelude/index.ts

@@ -40,6 +40,7 @@ export const globals = {
   'var?': function (this: VM, v: string) {
     return typeof v !== 'string' || this.scope.has(v)
   },
+  ref: (fn: Function) => fn,
 
   // type predicates
   'string?': (v: any) => toValue(v).type === 'string',

src/prelude/tests/info.test.ts

@@ -77,3 +77,15 @@ describe('introspection', () => {
     await expect(`describe 'hello'`).toEvaluateTo("#<string: \u001b[32m'hello\u001b[32m'\u001b[0m>", globals)
   })
 })
+
+describe('ref', () => {
+  expect(`rnd = do x: true end; rnd | type`).toEvaluateTo('boolean')
+  expect(`rnd = do x: true end; ref rnd | type`).toEvaluateTo('function')
+
+  expect(`math.random | type`).toEvaluateTo('number')
+  expect(`ref math.random | type`).toEvaluateTo('native')
+
+  expect(`rnd = math.random; rnd | type`).toEvaluateTo('number')
+  expect(`rnd = ref math.random; rnd | type`).toEvaluateTo('number')
+  expect(`rnd = ref math.random; ref rnd | type`).toEvaluateTo('native')
+})