many1

many1(p: Parser, m?: string): Parser

Applies a parser as many times as possible until it fails, collecting the results into a resulting array.

many1 executes a parser one or more times, as long as it continues to succeed. The operation of the parser in EBNF is p+. When the parser fails, that does not mean that many1 fails (as long as the parser succeeded at least once); that signals that many1 is through executing and the successful results up to that point are returned.

As long as p succeeds at least once, the only way many1 can fail is if p fails fatally.

Example

const parser = many1(right(digit(), letter()))

const s = parse(parser, '1a2b')
console.log(status(s))  // "ok"
console.log(success(s)) // ["a", "b"]

const f = parse(parser, 'aabb')
console.log(status(f))  // "fail"
console.log(failure(f)) // Parse error at (line 1, column 2):
                        //
                        // aabb
                        // ^
                        // Expected a digit

const t = parse(parser, '112b')
console.log(status(t))  // "fatal"
console.log(failure(t)) // Parse error at (line 1, column 2):
                        //
                        // 112b
                        //  ^
                        // Expected a letter

Parameters

• p: The parser to apply repeatedly until it fails.
• m: The optional expected error message that will take the place of the default error message.

Success

• Succeeds if p succeeds at least once and does not fail fatally. Returns the results that p had before failing in an array.

Failure

• Fails if p does not succeed at least once.

Fatal Failure

• Fails fatally if p fails fatally.

Throws

• Throws an error if p is not a parser.
• Throws an error if m exists and is not a string.

See Also

• Parser
• many