maximal-munch-rule-longest-match

IN premise — entries/2026/06/21/wiki-Tokenization_lexical_analysis.md

Created 2026-06-21T09:50:11+00:00

The maximal munch (longest match) rule requires the scanner to always match the longest possible lexeme from the input.

Summary

When a scanner reads source code and could break it into tokens in more than one valid way, it must always grab the longest stretch of characters that forms a legal token. This removes ambiguity from tokenization, so every input string maps to exactly one correct sequence of tokens and the rest of the compiler can rely on a single, unambiguous stream.