parsergen-backend-typescript.md

Parser Generator Backend: TypeScript

This backend outputs a parser as TypeScript source code. See parser generator backends for what every generated parser does and scanner generator backend: TypeScript for the scanner side.

The output is an ES module and needs nothing beyond the language itself.

--backend-typescript-scanner-module sets the module specifier the token constants are imported from, which defaults to ./scanner.js.

Parser.parse takes a TokenSource and returns a ParseResult holding the tree and the errors, and can be called again with another scanner. The tree is null when the parse could not be finished. Lexemes are a Uint8Array viewing into the source rather than a copy of it.

Example

examples/calculator/typescript/ is a calculator built on this backend. Its parser was generated with:

golr parser \
  --frontend golr \
  --frontend-file-path calculator.golr \
  --backend typescript \
  --backend-file-path parser/parser.ts