Class: Lrama::Grammar::Rule

Inherits:
Struct
  • Object
show all
Defined in:
lib/lrama/grammar/rule.rb

Overview

_rhs holds original RHS element. Use rhs to refer to Symbol.

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#_lhs ⇒ Object

Returns the value of attribute _lhs

Returns:

  • (Object) —

    the current value of _lhs



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# File 'lib/lrama/grammar/rule.rb', line 6

def _lhs
  @_lhs
end

#_rhs ⇒ Object

Returns the value of attribute _rhs

Returns:

  • (Object) —

    the current value of _rhs



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# File 'lib/lrama/grammar/rule.rb', line 6

def _rhs
  @_rhs
end

#id ⇒ Object

Returns the value of attribute id

Returns:

  • (Object) —

    the current value of id



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# File 'lib/lrama/grammar/rule.rb', line 6

def id
  @id
end

#lhs ⇒ Object

Returns the value of attribute lhs

Returns:

  • (Object) —

    the current value of lhs



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# File 'lib/lrama/grammar/rule.rb', line 6

def lhs
  @lhs
end

#lhs_tag ⇒ Object

Returns the value of attribute lhs_tag

Returns:

  • (Object) —

    the current value of lhs_tag



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# File 'lib/lrama/grammar/rule.rb', line 6

def lhs_tag
  @lhs_tag
end

#lineno ⇒ Object

Returns the value of attribute lineno

Returns:

  • (Object) —

    the current value of lineno



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# File 'lib/lrama/grammar/rule.rb', line 6

def lineno
  @lineno
end

#nullable ⇒ Object

Returns the value of attribute nullable

Returns:

  • (Object) —

    the current value of nullable



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# File 'lib/lrama/grammar/rule.rb', line 6

def nullable
  @nullable
end

#original_rule ⇒ Object

Returns the value of attribute original_rule.



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# File 'lib/lrama/grammar/rule.rb', line 7

def original_rule
  @original_rule
end

#position_in_original_rule_rhs ⇒ Object

Returns the value of attribute position_in_original_rule_rhs

Returns:

  • (Object) —

    the current value of position_in_original_rule_rhs



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# File 'lib/lrama/grammar/rule.rb', line 6

def position_in_original_rule_rhs
  @position_in_original_rule_rhs
end

#precedence_sym ⇒ Object

Returns the value of attribute precedence_sym

Returns:

  • (Object) —

    the current value of precedence_sym



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# File 'lib/lrama/grammar/rule.rb', line 6

def precedence_sym
  @precedence_sym
end

#rhs ⇒ Object

Returns the value of attribute rhs

Returns:

  • (Object) —

    the current value of rhs



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# File 'lib/lrama/grammar/rule.rb', line 6

def rhs
  @rhs
end

#token_code ⇒ Object

Returns the value of attribute token_code

Returns:

  • (Object) —

    the current value of token_code



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# File 'lib/lrama/grammar/rule.rb', line 6

def token_code
  @token_code
end

Instance Method Details

#==(other) ⇒ Object 



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# File 'lib/lrama/grammar/rule.rb', line 9

def ==(other)
  self.class == other.class &&
  self.lhs == other.lhs &&
  self.lhs_tag == other.lhs_tag &&
  self.rhs == other.rhs &&
  self.token_code == other.token_code &&
  self.position_in_original_rule_rhs == other.position_in_original_rule_rhs &&
  self.nullable == other.nullable &&
  self.precedence_sym == other.precedence_sym &&
  self.lineno == other.lineno
end

#as_comment ⇒ Object

Used by #user_actions



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# File 'lib/lrama/grammar/rule.rb', line 37

def as_comment
  l = lhs.id.s_value
  r = empty_rule? ? "%empty" : rhs.map(&:display_name).join(" ")

  "#{l}: #{r}"
end

#contains_at_reference? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/lrama/grammar/rule.rb', line 68

def contains_at_reference?
  return false unless token_code

  token_code.references.any? {|r| r.type == :at }
end

#display_name ⇒ Object 



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# File 'lib/lrama/grammar/rule.rb', line 21

def display_name
  l = lhs.id.s_value
  r = empty_rule? ? "ε" : rhs.map {|r| r.id.s_value }.join(" ")
  "#{l} -> #{r}"
end

#display_name_without_action ⇒ Object 



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# File 'lib/lrama/grammar/rule.rb', line 27

def display_name_without_action
  l = lhs.id.s_value
  r = empty_rule? ? "ε" : rhs.map do |r|
    r.id.s_value if r.first_set.any?
  end.compact.join(" ")

  "#{l} -> #{r}"
end

#empty_rule? ⇒ Boolean

opt_nl: ε <– empty_rule

| '\n'  <-- not empty_rule

Returns:

  • (Boolean) 


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# File 'lib/lrama/grammar/rule.rb', line 50

def empty_rule?
  rhs.empty?
end

#initial_rule? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/lrama/grammar/rule.rb', line 58

def initial_rule?
  id == 0
end

#precedence ⇒ Object 



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# File 'lib/lrama/grammar/rule.rb', line 54

def precedence
  precedence_sym&.precedence
end

#translated_code ⇒ Object 



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# File 'lib/lrama/grammar/rule.rb', line 62

def translated_code
  return nil unless token_code

  Code::RuleAction.new(type: :rule_action, token_code: token_code, rule: self).translated_code
end

#with_actions ⇒ Object 



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# File 'lib/lrama/grammar/rule.rb', line 44

def with_actions
  "#{display_name} {#{token_code&.s_value}}"
end