PEGO
G010: Generated Helper Sharing
Generated parsers can repeat identical expression methods and literal tables. Sharing exact emitted helpers reduces generated source duplication without merging rule identities.
Mechanism and Invariants
Helper interning requires an identical method signature and complete body. Rule wrappers remain separate, preserving memo keys, depth, captures and expectations. Failed speculative direct lowering rolls back inserted helper entries and reserved names, so later code cannot call a discarded helper. Literal-table sharing is a separate registry and selector.
Scope and State
Default helper sharing in generated Go Node, typed Go and TypeScript. Closure and VMs are outside this generator mechanism.
Reference Control
Private disableMethodSharing produces a same-generator duplicate-helper
reference. Literal sharing can be held fixed independently; no matching-time
selector is emitted.
Evidence and Implementation
Record 090 measures emitted-source changes and paired generated workloads in Go/TypeScript. Its mixed-use TypeScript literal results did not justify default adoption. Source reduction does not by itself prove lower matching time; use the record's separate configurations and workload results rather than assigning one universal speedup.
Evidence records: 090.
Source owners: Generator.Method,
gen.Generator.LiteralName interning,
TypeScript sharing policy.
The comparison policy distinguishes same-source controls, historical changes and full checkpoints.