Parséman100% Pure Parsing

Write parsers as TypeScript functions. Ship them like hand-written parsers. Same grammar interpreted in tests, macro-compiled in production. No grammar files, no generated output to check in.

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Compiles to flat JavaScript

Add the bundler plugin and your combinator trees are evaluated at build time and replaced with inline functions. The macro'd import disappears entirely — the compiled grammar carries no parseman import.

Macro mode

Just functions, all the way down

literal, choice, sequence, many, node… compose plain functions. No DSL, no code-generation step to run, no generated files to commit.

Combinators

CST / AST with trivia capture

node() rules capture terminals and whitespace/comment offsets for you — no wrapping terminals to recover spans. Purpose-built for editors, formatters, and incremental re-parsing.

Building trees

An editor backend, not just a parser

Tolerant recovery runs on the compiled parser, not just the interpreter — and an external language-service layer adds completions and diagnostics keyed by node type, over a grammar that stays pure. Recover, complete, diagnose: a real language server.

Editor integration

Aged for speed

On JSON, CSV, and GraphQL the macro build beats Peggy at every fixture size; compiled CST beats Lezer on tree-building too.

Benchmarks

Debuggable output

Interpreter mode runs your combinator source directly. Macro build compiles it away but keeps breakpoints working via source maps — you step through choice(...), not charCode dispatch.

Debugging by mode

Scannerless, with routing

dispatch() parses a shared head once, then routes by the value or marker the grammar just read. You keep scannerless flexibility without turning overlapping lexical shapes into broad backtracking.

Dispatch