seq

seq(...ps: Parser[], m?: string): Parser

Applies a series of parsers in order, returning an array that contains each parser's result.

seq will only succeed if all of its parsers succeed. If one of them fails, seq will fail fatally if it had consumed any input up to that point, even if the parser that failed did so non-fatally.

There is another version of this parser (bseq) that fails non-fatally and backtracks if the parser that fails does so non-fatally.

All of the results are gathered into an array.

Example

const parser = seq(letter(), digit(), letter())

const s = parse(parser, 'a1b')
console.log(status(s))  // "ok"
console.log(success(s)) // ["a", "1", "b"]

const f = parse(parser, '11b')
console.log(status(f))  // "fail"
console.log(failure(f)) // Parse error at (line 1, column 1):
                        //
                        // 11b
                        // ^
                        // Expected a letter

const t = parse(parser, 'a11')
console.log(status(t))  // "fatal"
console.log(failure(t)) // Parse error at (line 1, column 3):
                        //
                        // a11
                        //   ^
                        // Expected a letter

Parameters

...ps: A series of parsers to apply to the input, one at a time, in order.
m: An optional message to be used as the expected error message in the event of failure, in place of the collected expected error messages of the parsers in ps.

Success

Succeeds if every parser in ps succeeds. Returns all of the results of the parsers in ps gathered into an array.

Failure

Fails if the first parser in ps fails.
Fails if any subsequent parser in ps fails after the prior parsers succeed but do not consume any input.

Fatal Failure

Fails fatally if any parser in ps fails fatally.
Fails fatally if any parser in ps fails after any prior parser succeeds and consumes some input.

Throws

Throws an error if any member of ps is not a parser.

seq