many

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

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

many executes a parser zero 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 many fails; that signals that many is through executing and the successful results up to that point are returned.

Example

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

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

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

The failure case in this example shows the only way that many can fail: its underlying right parser fails fatally because it consumed input before failing, and that fatal failure causes many to fail. many does not fail from non-fatal failures of its parser.

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 does not fail fatally. Returns the results that p had before failing in an array.

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
• many1