Skip to content

alpha

alpha(m?: string): Parser

Parses an ASCII alphanumeric character (0-9, a-z, or A-Z).

This does not parse UTF-8 alphanumeric characters in general. Use ualpha for that.

Example

const parser = alpha()

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

const f = parse(parser, '---')
console.log(status(f))  // "fail"
console.log(failure(f)) // Parse error at (line 1, column 1):
                        //
                        // ---
                        // ^
                        // Expected an alphanumeric character

Parameters

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

Success

  • Succeeds if the next character is an ASCII alphanumeric character (0-9, a-z, or A-Z). 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