Class: Coradoc::Markdown::Parser::ParsletExtras::Lookbehind

Inherits:
Parslet::Atoms::Base
  • Object
show all
Defined in:
lib/coradoc/markdown/parser/parslet_extras.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(bound_parslet, number, positive: true) ⇒ Lookbehind

Returns a new instance of Lookbehind.



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# File 'lib/coradoc/markdown/parser/parslet_extras.rb', line 115

def initialize(bound_parslet, number, positive: true)
  super()

  # Model positive and negative lookbehind by testing this flag.
  @positive = positive
  @number = number
  @bound_parslet = bound_parslet
end

Instance Attribute Details

#bound_parslet ⇒ Object (readonly)

Returns the value of attribute bound_parslet.



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# File 'lib/coradoc/markdown/parser/parslet_extras.rb', line 113

def bound_parslet
  @bound_parslet
end

#number ⇒ Object (readonly)

Returns the value of attribute number.



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# File 'lib/coradoc/markdown/parser/parslet_extras.rb', line 113

def number
  @number
end

#positive ⇒ Object (readonly)

Returns the value of attribute positive.



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# File 'lib/coradoc/markdown/parser/parslet_extras.rb', line 112

def positive
  @positive
end

Instance Method Details

#error_msgs ⇒ Object 



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# File 'lib/coradoc/markdown/parser/parslet_extras.rb', line 124

def error_msgs
  @error_msgs ||= {
    positive: ['Input should be preceded by ', bound_parslet],
    negative: ['Input should not be preceded by ', bound_parslet]
  }
end

#to_s_inner(prec) ⇒ Object 



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# File 'lib/coradoc/markdown/parser/parslet_extras.rb', line 156

def to_s_inner(prec)
  @char = positive ? '&' : '!'
  "<#{@char}<#{number}<#{bound_parslet.to_s(prec)}"
end

#try(source, context, consume_all) ⇒ Object 



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# File 'lib/coradoc/markdown/parser/parslet_extras.rb', line 131

def try(source, context, consume_all)
  rewind_pos = source.bytepos
  if source.bytepos.zero?
    return succ(nil) unless positive

    return context.err_at(self, source, error_msgs[:positive], source.pos)
  end
  source.rewind(number)
  error_pos = source.pos

  success, = bound_parslet.apply(source, context, consume_all)

  if positive
    return succ(nil) if success

    context.err_at(self, source, error_msgs[:positive], error_pos)
  else
    return succ(nil) unless success

    context.err_at(self, source, error_msgs[:negative], error_pos)
  end
ensure
  source.bytepos = rewind_pos
end