Class: RubyPP

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

Defined Under Namespace

Classes: Environment

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(input, output, filename) ⇒ RubyPP

Returns a new instance of RubyPP.



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# File 'lib/rubypp.rb', line 20

def initialize(input, output, filename)
  @input = input
  @output = output
  @filename = filename
  @linenum = 1
  @environment = Environment.new(self)
  @binding = @environment.binding
end

Instance Attribute Details

#filename ⇒ Object (readonly)

Returns the value of attribute filename.



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# File 'lib/rubypp.rb', line 18

def filename
  @filename
end

#input ⇒ Object (readonly)

Returns the value of attribute input.



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# File 'lib/rubypp.rb', line 16

def input
  @input
end

#output ⇒ Object (readonly)

Returns the value of attribute output.



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# File 'lib/rubypp.rb', line 17

def output
  @output
end

Instance Method Details

#evaluate(str, linenum) ⇒ Object 



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# File 'lib/rubypp.rb', line 81

def evaluate(str, linenum)
  result = eval(str, @binding, @filename, linenum)
  return result
end

#getline ⇒ Object 



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# File 'lib/rubypp.rb', line 29

def getline
  line = @input.gets
  @linenum += 1 if not line.nil?
  return line
end

#preprocess ⇒ Object 



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# File 'lib/rubypp.rb', line 35

def preprocess
  success = false
  begin
    loop do
      line = getline
      break if line.nil?
      case line
      when /(.*[^\\]|^)\#\{(.*?)\}(.*)/
        @output.puts "#{$1}#{evaluate($2, @linenum)}#{$3}"
      when /^\#ruby\s+<<(.*)/
        marker = $1
        str = ''
        evalstart = @linenum
        loop do
          line = getline
          if line.nil? then
            raise "End of input without #{marker}"
          end
          break if line.chomp == marker
          str << line
        end
        result = evaluate(str, evalstart)
        @output.puts result if not result.nil?
      when /^\#ruby\s+(.*)/
        str = line = $1
        while line[-1] == ?\\
          str.chop!
          line = getline
          break if line.nil?
          line.chomp!
          str << line
        end
        result = evaluate(str, @linenum)
        @output.puts result if not result.nil?
      else
        @output.puts line
      end
    end
    success = true
  ensure
    if not success then
      $stderr.puts "Error on line #{@linenum}:"
    end
  end
end