Class: Dhaka::LexerSupport::State

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

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(state_machine, pattern) ⇒ State

Returns a new instance of State.



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# File 'lib/lexer/state.rb', line 5

def initialize state_machine, pattern
  @state_machine = state_machine
  @pattern          = pattern
  @transitions      = {}
end

Instance Attribute Details

#pattern ⇒ Object (readonly)

Returns the value of attribute pattern.



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# File 'lib/lexer/state.rb', line 4

def pattern
  @pattern
end

#transitions ⇒ Object (readonly)

Returns the value of attribute transitions.



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# File 'lib/lexer/state.rb', line 4

def transitions
  @transitions
end

Instance Method Details

#accepting? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/lexer/state.rb', line 11

def accepting?
  pattern
end

#compile_to_ruby_source ⇒ Object 



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# File 'lib/lexer/state.rb', line 26

def compile_to_ruby_source
  result  = "  at_state(#{object_id}) {\n"
  result << "    recognize(#{pattern.inspect})\n" if accepting?
  transition_keys_by_destination_state = Hash.new {|hash, key| hash[key] = []}
  transitions.each do |key, dest_state|
    transition_keys_by_destination_state[dest_state.object_id] << key
  end

  transition_keys_by_destination_state.keys.each do |state_id|
    transition_keys = transition_keys_by_destination_state[state_id].collect {|transition_key| "#{transition_key.inspect}"}.join(', ')
    result << "    for_characters(#{transition_keys}) { switch_to #{state_id} }\n"
  end

  result << "  }"
  result
end

#for_characters(*characters, &blk) ⇒ Object 



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# File 'lib/lexer/state.rb', line 15

def for_characters *characters, &blk
  dest_state = @state_machine.instance_eval(&blk)
  characters.each do |char|
    transitions[char] = dest_state
  end
end

#recognize(pattern) ⇒ Object 



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# File 'lib/lexer/state.rb', line 22

def recognize pattern
  @pattern = pattern
end