Template Engine II

Requirements

• Export renderTemplate(template, data) as named and default, and compileTemplate(template). The latter returns a reusable render(data) function and parses the template once. Data is a record of unknown values; rendering must not modify it.
• Support {{ path }} for escaped output and {{{ path }}} for raw output. Paths consist of ASCII letters/digits/underscore/dollar segments separated by dots, optionally followed by bracketed nonnegative integer array indices: user.name, items[0].name, and matrix[1][2]. Whitespace around the whole path is allowed; whitespace inside a path is not.
• Bracket indices must be 0 or positive integers without leading zeros. Brackets address arrays only. Dotted segments resolve own properties of objects, including numeric array keys. Never traverse __proto__, constructor, or prototype. A missing segment or null/undefined terminal value renders an empty string; other values use String(value), preserving false and zero.
• Double braces escape &, <, >, double quotes, and single quotes as &amp;, &lt;, &gt;, &quot;, and &#39;. Triple braces insert the value unchanged and are intended for trusted markup. Do not rescan inserted values as templates.
• Only balanced double or triple placeholders with supported paths are substituted. Empty placeholders, expressions, invalid indices, and unsupported brace counts remain literal. Parse each outer placeholder as one unit; do not substitute a smaller placeholder inside a malformed larger one.
• No function calls, JavaScript expression evaluation, loops, sections, filters, nested template expansion, DOM manipulation, or full HTML/CSS authoring is required. Encoding is text/HTML escaping; context-specific script or URL escaping is outside scope.

Examples

Input: renderTemplate("Hello {{ users[0].name }}! {{{ trusted }}}", {users:[{name:"Ada & Lin"}],trusted:"<b>ready</b>"});
Output: Hello Ada &amp; Lin! <b>ready</b>

Input: const render = compileTemplate("{{ user.name }}: {{ count }}"); render({user:{name:"Ada"},count:0});
Output: Ada: 0