letter function

  1. @useResult
Parser<String> letter([
  1. String message = 'letter expected'
])

Returns a parser that accepts any letter character (lowercase or uppercase). The accepted input is equivalent to the character-set a-zA-Z.

Implementation

@useResult
Parser<String> letter([String message = 'letter expected']) =>
    SingleCharacterParser(const LetterCharPredicate(), message);