digit

digit(m?: string): Parser

Parses a decimal digit (0-9).

Note that this parses ASCII digits, not UTF-8 digits in general. For that, use regex(/^\p{Nd}/u).

Example

const parser = digit()

const s = parse(parser, '123')
console.log(status(s))  // "ok"
console.log(success(s)) // "1"

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

Parameters

• m: The optional expected error message that will take the place of the default error message.

Success

• Succeeds if the next character is a decimal digit (0-9). Consumes and returns that character.

Failure

• Fails if the next character is any other character.

Throws

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

See Also

• Parser
• hex
• octal