Class: Racc::LocationPointer

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

Overview

A set of rule and position in it’s RHS. Note that the number of pointers is more than rule’s RHS array, because pointer points right edge of the final symbol when reducing.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(rule, i, sym) ⇒ LocationPointer

Returns a new instance of LocationPointer.



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# File 'lib/racc/grammar.rb', line 891

def initialize(rule, i, sym)
  @rule   = rule
  @index  = i
  @symbol = sym
  @ident  = @rule.hash + i
  @reduce = sym.nil?
end

Instance Attribute Details

#ident ⇒ Object (readonly) Also known as: hash

Returns the value of attribute ident.



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# File 'lib/racc/grammar.rb', line 905

def ident
  @ident
end

#index ⇒ Object (readonly)

Returns the value of attribute index.



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# File 'lib/racc/grammar.rb', line 900

def index
  @index
end

#reduce ⇒ Object (readonly) Also known as: reduce?

Returns the value of attribute reduce.



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# File 'lib/racc/grammar.rb', line 907

def reduce
  @reduce
end

#rule ⇒ Object (readonly)

Returns the value of attribute rule.



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# File 'lib/racc/grammar.rb', line 899

def rule
  @rule
end

#symbol ⇒ Object (readonly) Also known as: dereference

Returns the value of attribute symbol.



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# File 'lib/racc/grammar.rb', line 901

def symbol
  @symbol
end

Instance Method Details

#before(len) ⇒ Object 



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# File 'lib/racc/grammar.rb', line 933

def before(len)
  @rule.ptrs[@index - len] or ptr_bug!
end

#eql?(ot) ⇒ Boolean Also known as: ==

Returns:

  • (Boolean) 


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# File 'lib/racc/grammar.rb', line 917

def eql?(ot)
  @hash == ot.hash
end

#head? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/racc/grammar.rb', line 923

def head?
  @index == 0
end

#next ⇒ Object Also known as: increment 



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# File 'lib/racc/grammar.rb', line 927

def next
  @rule.ptrs[@index + 1] or ptr_bug!
end

#to_s ⇒ Object Also known as: inspect 



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# File 'lib/racc/grammar.rb', line 910

def to_s
  sprintf('(%d,%d %s)',
          @rule.ident, @index, (reduce?() ? '#' : @symbol.to_s))
end