PEGO
M130: Short Literal Comparisons
Generated direct Go rules can match common punctuation without calling the general literal helper on the successful path.
Mechanism and Invariants
Literals of at most four code points compare against decoded input in place.
Failure or insufficient input goes through matchLiteral, preserving
matched-prefix position and expectation behavior. Bytes always uses the general
matcher. Unicode literals and one-to-five-point boundary tests prevent
accidentally treating byte length as character count.
Scope and State
Default eligible generated Go Node and typed direct bodies in CodePoints. Longer literals, fallback bodies, Bytes and other backends retain their literal route.
Reference Control
No short-literal-only same-source control exists; broader direct-body controls also change unrelated expression dispatch.
Evidence and Implementation
Historical record 062 measures typed JSON 3.34 to 3.16 ms, XML 3.89 to 3.80 ms and Outline 2.14 to 1.97 ms. These do not establish current Node, Bytes or all-literal effects.
Evidence records: 062.
Source owners: Flow literal comparison lowering,
parser.matchLiteral.
The comparison policy distinguishes same-source controls, historical changes and full checkpoints.