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Apr 25, 2021 · Fundamentals

Understanding ECMAScript Grammar: Lexical, Syntactic, and Identifier Rules

This article examines the four ECMAScript grammars—lexical, syntactic, regular‑expression, and numeric‑string—explains how context‑free productions define tokens, shows ambiguous cases such as the '/' and '`' characters, and details why the identifier await is prohibited in async functions through static‑semantic rules.