bright
bright(p: Parser, q: Parser, m?: string): Parser
Applies two parsers in order, returning the result of the second one.
The result of the first parser is discarded. If either parser fails, then the entire bright
parser also fails. If input was consumed by either parser and one of them fails, backtracking will take the state back to where it was before p
was applied.
Example
const parser = bright(letter(), digit())
const s = parse(parser, 'a1')
console.log(status(s)) // "ok"
console.log(success(s)) // "1"
const f = parse(parser, '12')
console.log(status(f)) // "fail"
console.log(failure(f)) // Parse error at (line 1, column 1):
//
// 12
// ^
// Expected a letter
const t = parse(parser, 'ab')
console.log(status(t)) // "fail"
console.log(failure(t)) // Parse error at (line 1, column 1):
//
// ab
// ^
// The parser backtracked after:
//
// Parse error at (line 1, column 2):
//
// ab
// ^
// Expected a digit
Parameters
p
: The first parser to apply. This parser's result will be discarded.q
: The second parser to apply. If both parsers succeed, this parser's result will berightB
's result.m
: The optional expected error message that will take the place of the default error message.
Success
- Succeeds if both
p
andq
succeed. Returns the result ofq
.
Failure
- Fails if either
p
orq
fails. If any input was consumed, backtracking will occur and an additional error message will be provided that details the circumstances of the backtracking.
Fatal Failure
- Fails fatally if either
p
orq
fail fatally.
Throws
- Throws an error if either
p
orq
are not parsers. - Throws an error if
m
exists and is not a string.