Class: Arcana::Rule

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

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(offset, pattern, message) ⇒ Rule

Returns a new instance of Rule.



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# File 'lib/arcana.rb', line 382

def initialize(offset, pattern, message)
  @offset = offset
  @pattern = pattern
  @message = message
  @extras = {}
  @children = []
end

Instance Attribute Details

#children ⇒ Object (readonly)

Returns the value of attribute children.



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# File 'lib/arcana.rb', line 380

def children
  @children
end

#extras ⇒ Object (readonly)

Returns the value of attribute extras.



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# File 'lib/arcana.rb', line 380

def extras
  @extras
end

#message ⇒ Object (readonly)

Returns the value of attribute message.



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# File 'lib/arcana.rb', line 380

def message
  @message
end

#offset ⇒ Object (readonly)

Returns the value of attribute offset.



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# File 'lib/arcana.rb', line 380

def offset
  @offset
end

#pattern ⇒ Object (readonly)

Returns the value of attribute pattern.



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# File 'lib/arcana.rb', line 380

def pattern
  @pattern
end

Instance Method Details

#inspect ⇒ Object 



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# File 'lib/arcana.rb', line 436

def inspect
  "<#{self.class} #{@offset} #{@pattern.inspect} #{@message}>"
end

#match(input, match) ⇒ Object 



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# File 'lib/arcana.rb', line 390

def match(input, match)
  return EMPTY_ARRAY if @offset.relative?
  #return EMPTY_ARRAY unless @offset.exact?
  ruleset = match.ruleset

  input = Cursor.new(input) unless Cursor === input
  @offset.seek(input)

  if pattern.type == "use"
    return EMPTY_ARRAY if pattern.value.start_with?("\\^") # FIXME: endianness swap
    use = ruleset.names.fetch(pattern.value)
    input.restore do
      input.mark_base # FIXME: no idea if this works
      return use.visit_children(input, match)
    end
  elsif pattern.type == "indirect"
    # FIXME: do this better
    original_input = input.buf
    return match.ruleset.match(original_input[input.offset..], match)
  end

  if @pattern.match?(input)
    match = match.add(self)
    child_matches = visit_children(input, match)
    if child_matches.any?
      child_matches
    else
      match
    end
  else
    EMPTY_ARRAY
  end
end

#mime_type ⇒ Object 



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# File 'lib/arcana.rb', line 432

def mime_type
  @extras["mime"]
end

#visit_children(input, match) ⇒ Object 



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# File 'lib/arcana.rb', line 424

def visit_children(input, match)
  children.flat_map do |child|
    input.restore do
      child.match(input, match)
    end
  end
end