Class: Antlers::Lexer

Inherits:
Object
  • Object
show all
Defined in:
lib/lexer.rb

Constant Summary collapse

FOR_KEYWORDS = 
['for:', 'in:', ':for'].freeze
FORM_KEYWORDS = 
['form:', ':form'].freeze

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Lexer

Returns a new instance of Lexer.



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# File 'lib/lexer.rb', line 14

def initialize
  @delimiters = ['<{', '}>', '{', '}']
  @keywords = ['if:', *FORM_KEYWORDS, *FOR_KEYWORDS, 'slot:', ':slot']
  @cursor = 0
end

Instance Method Details

#parse(template) ⇒ Object 



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# File 'lib/lexer.rb', line 20

def parse(template)
  @cursor = 0
  sequence = []

  # Split on delimiters and retain capture groups.
  segments = template.split(/(#{Regexp.union(@delimiters)})/).map(&:strip)

  until segments[@cursor].nil?
    if (antlers_segment = antlers_segment(segments:))
      sequence << antlers_lexeme(antlers_segment:, segments:)
      # Skipping: ['{', 'expression', '}']
      # Skipping: ['<{', 'name + props + keywords', '}>']
      @cursor += 3
    else
      segment = segments[@cursor]
      sequence << segment unless segment.empty?
      @cursor += 1
    end
  end

  sequence
end