PEGO
G070: Literal Text Predicates
A pure OR of comparisons against one capture's text can compute that text once and dispatch by literal, rather than repeat general expression evaluation for every branch.
Mechanism and Invariants
The complete predicate must contain at least two comparisons of the same direct capture with string literals; either operand order is accepted. The emitter collapses duplicate literals and emits a switch. Mixed expressions, aliases, bindings and different captures remain general, preserving short-circuit order and side effects. Helper/literal-table sharing is independent of this shape specialization. Generated Go and TypeScript use the switch on ordinary nil-control calls; active work-controlled calls keep the general charged evaluator.
Scope and State
Default eligible predicates in generated Go Node, typed Go and TypeScript. Closure and both VMs retain their general action evaluator for this disjunction shape.
Reference Control
Private generation option disableLiteralTextDispatch emits the general
predicate from the same generator. It adds no runtime selector or public option.
Evidence and Implementation
Record 091 compares the same generator with dispatch disabled. Large Go workloads have paired geometric-mean time ratios about 0.952/0.955 in CodePoints/Bytes, while small-workload means are 1.001/0.990. TypeScript has separate scoped gains and a slower first-match case. No-op source is byte-identical. These results concern qualifying pure predicates, not arbitrary OR expressions or all parsers.
Evidence records: 091.
Source owners: literal text dispatch recognition/emission, TypeScript literal switch emission, route and unsafe-shape checks.
The comparison policy distinguishes same-source controls, historical changes and full checkpoints.