trie: add get function

lib/util/trie.js

@@ -160,6 +160,19 @@ export const suggest = trie => key => maxSuggestions => {
   return __suggest(trie, "", key, maxSuggestions);
 }
 
+export const get = trie => key => {
+  if (key === '') {
+    return trie.value;
+  }
+  const [pos] = binarySearch(trie.children, key);
+  if (pos < trie.children.length) {
+    const [haveKey, haveChildNode] = trie.children[pos];
+    if (key.startsWith(haveKey)) {
+      return get(haveChildNode)(key.slice(haveKey.length));
+    }
+  }
+}
+
 const __suggest = (trie, path, remaining, maxSuggestions) => {
   if (maxSuggestions === 0) {
     return [];

tests/trie.js

@@ -3,7 +3,9 @@ import * as assert from "node:assert";
 import { module2Env } from "../lib/environment/env.js";
 import { ModuleStd } from "../lib/stdlib.js";
 import { pretty } from "../lib/util/pretty.js";
-import { emptyTrie, growPrefix, insert, isProperlySorted, suggest } from "../lib/util/trie.js";
+import { emptyTrie, get, growPrefix, insert, isProperlySorted, suggest } from "../lib/util/trie.js";
+import { push } from "../lib/structures/list.js";
+import { getInst } from "../lib/primitives/dynamic.js";
 
 
 ///////////////////
@@ -105,3 +107,13 @@ assert.deepEqual(
   suggest(bigTrie)("df")(2),
   []
 );
+
+assert.equal(
+  getInst(get(bigTrie)("list.push")),
+  push
+);
+
+assert.equal(
+  get(bigTrie)("ooo"),
+  undefined
+);