Class: NsMacroProcessor::Tokens

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

Constant Summary collapse

EOF = 
-1

Instance Method Summary collapse

Constructor Details

#initialize(input) ⇒ Tokens

Returns a new instance of Tokens.



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# File 'lib/ns_macro_processor/tokens.rb', line 7

def initialize(input)
  @input = input
end

Instance Method Details

#advance ⇒ Object 



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# File 'lib/ns_macro_processor/tokens.rb', line 11

def advance
  if @input.nil? || @input.empty?
    @current = EOF
    return
  end
  ix = 0
  if whitespace?(@input[ix])
    while ix < @input.length && whitespace?(@input[ix])
      ix += 1
    end
    @current = ' '
    @input = @input[ix..-1]
    return
  end
  if ident_start?(@input[ix])
    while ix < @input.length && ident?(@input[ix])
      ix += 1
    end
    @current = @input[0, ix]
    @input = @input[ix..-1]
    return
  end
  @current = @input[0]
  @input = @input[1..-1]
end

#peek ⇒ Object 



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# File 'lib/ns_macro_processor/tokens.rb', line 37

def peek
  @current
end

#push_back(str) ⇒ Object 



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# File 'lib/ns_macro_processor/tokens.rb', line 41

def push_back(str)
  @input = (@current == EOF) ? str + @input : str + @current + @input
  advance
end