inner

inner combinator takes three or more parsers and applies them in order. Returns the values of all but the first and the last parsers.

Given exactly three parsers, the value of the middle one is returned as is. Given more, the values in between are returned as a tuple.

Usage

const Parser = inner(
  sequence(string('fn'), whitespace()),
  letters(),
  rest()
)

Success

run(Parser).with('fn multiply x y')

{
  isOk: true,
  start: 0,
  end: 15,
  pos: 15,
  value: 'multiply'
}

Failure

run(Parser).with('fn 100 x y')

{
  isOk: false,
  start: 3,
  end: 3,
  pos: 3,
  expected: 'letters'
}

Tuple of inner values

With four or more parsers the values in between come back as a tuple.

const Parser = inner(
  string('('),
  whole(),
  string(','),
  whole(),
  string(')')
)

Success

run(Parser).with('(1,2)')

{
  isOk: true,
  start: 0,
  end: 5,
  pos: 5,
  value: [ 1, ',', 2 ]
}