run

run is used to run parser with provided input.

Usage

Success

run(string('hello world')).with('hello world')

{
  isOk: true,
  start: 0,
  end: 11,
  pos: 11,
  value: 'hello world',
  errors: []
}

Failure

run(string('hello world')).with('bye')

{
  isOk: false,
  start: 0,
  end: 3,
  pos: 0,
  expected: 'hello world',
  label: null,
  errors: []
}

Recovered failures

Every result carries errors, the failures the run recovered from via recover. A result with a non-empty errors and isOk: true is a partial parse: the value is usable and each entry describes a syntax error. Failures additionally carry label, set by commit.

run tolerates recovered failures; tryRun throws on them.

const Statement = map(
  first(last(string('let '), commit(letters(), 'stmt')), string(';')),
  (name) => ({ kind: 'let', name })
)

const Program = many(
  recover(Statement, syncPast(string(';')), (_failure, span) => ({ kind: 'error', span }))
)

run(Program).with('let a;let ;let c;')

{
  isOk: true,
  start: 0,
  end: 17,
  pos: 17,
  value: [
    { kind: 'let', name: 'a' },
    { kind: 'error', span: { start: 6, end: 11 } },
    { kind: 'let', name: 'c' }
  ],
  errors: [
    { isOk: false, start: 10, end: 10, pos: 10, expected: 'letters', label: 'stmt', errors: [] }
  ]
}

Examples on the other pages omit errors and label for brevity, but both are always present.