Module: Repper::Tokenizer

Defined in:
lib/repper/tokenizer.rb

Class Method Summary collapse

Class Method Details

.call(regexp, delimiters: ['/', '/'], flags: nil) ⇒ Object 



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# File 'lib/repper/tokenizer.rb', line 7

def call(regexp, delimiters: ['/', '/'], flags: nil)
  tree = Regexp::Parser.parse(regexp, options: flags =~ /x/ && Regexp::EXTENDED)
  flatten(tree, delimiters: delimiters, flags: flags)
rescue ::Regexp::Parser::Error => e
  raise e.extend(Repper::Error)
end

.flatten(exp, acc = [], delimiters: nil, flags: nil) ⇒ Object

Turn Regexp::Parser AST back into a flat Array of visual elements that match the Regexp notation.



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# File 'lib/repper/tokenizer.rb', line 16

def flatten(exp, acc = [], delimiters: nil, flags: nil)
  # Add opening entry.
  exp.is?(:root) && acc << make_token(exp, delimiters[0])

  # Ignore nesting of invisible intermediate branches for better visuals.
  exp.is?(:sequence) && exp.nesting_level -= 1

  exp.parts.each do |part|
    if part.instance_of?(::String)
      acc << make_token(exp, part)
    else # part.is_a?(Regexp::Expression::Base)
      flatten(part, acc)
    end
  end

  exp.quantified? && flatten(exp.quantifier, acc)

  # Add closing entry.
  exp.is?(:root) && begin
    flags ||= exp.options.keys.join
    acc << make_token(exp, "#{delimiters[1]}#{flags.chars.uniq.sort.join}")
  end

  acc
end

.make_token(exp, text) ⇒ Object 



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# File 'lib/repper/tokenizer.rb', line 42

def make_token(exp, text)
  Token.new(
    type:    exp.type,
    subtype: exp.token,
    level:   exp.nesting_level,
    text:    text,
    id:      exp.respond_to?(:identifier) && exp.identifier,
  )
end