Class: Smurf::Javascript

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

Constant Summary collapse

EOF = 
-1

Instance Method Summary collapse

Constructor Details

#initialize(content) ⇒ Javascript

Returns a new instance of Javascript.



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# File 'lib/smurf/javascript.rb', line 46

def initialize(content)
  @input = StringIO.new(content)
  @output = StringIO.new
  jsmin
end

Instance Method Details

#action(a) ⇒ Object

action – do something! What you do is determined by the argument: 1 Output A. Copy B to A. Get the next B. 2 Copy B to A. Get the next B. (Delete A). 3 Get the next B. (Delete B). action treats a string as a single character. Wow! action recognizes a regular expression if it is preceded by ( or , or =.



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# File 'lib/smurf/javascript.rb', line 120

def action(a)
  if(a==1)
    @output.write @theA
  end
  if(a==1 || a==2)
    @theA = @theB
    if (@theA == "\'" || @theA == "\"")
      while (true)
        @output.write @theA
        @theA = get
        break if (@theA == @theB)
        raise "Unterminated string literal" if (@theA <= "\n")
        if (@theA == "\\")
          @output.write @theA
          @theA = get
        end
      end
    end
  end
  if(a==1 || a==2 || a==3)
    @theB = mynext
    if (@theB == "/" && (@theA == "(" || @theA == "," || @theA == "=" ||
                         @theA == ":" || @theA == "[" || @theA == "!" ||
                         @theA == "&" || @theA == "|" || @theA == "?" ||
                         @theA == "{" || @theA == "}" || @theA == ";" ||
                         @theA == "\n"))
      @output.write @theA
      @output.write @theB
      while (true)
        @theA = get
        if (@theA == "/")
          break
        elsif (@theA == "\\")
          @output.write @theA
          @theA = get
        elsif (@theA <= "\n")
          raise "Unterminated RegExp Literal"
        end
        @output.write @theA
      end
      @theB = mynext
    end
  end
end

#get ⇒ Object

get – return the next character from stdin. Watch out for lookahead. If the character is a control character, translate it to a space or linefeed.



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# File 'lib/smurf/javascript.rb', line 68

def get()
  c = @input.getc
  return EOF if(!c)
  c = c.chr
  return c if (c >= " " || c == "\n" || c.unpack("c") == EOF)
  return "\n" if (c == "\r")
  return " "
end

#isAlphanum(c) ⇒ Object

isAlphanum – return true if the character is a letter, digit, underscore, # dollar sign, or non-ASCII character



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# File 'lib/smurf/javascript.rb', line 59

def isAlphanum(c)
  return false if !c || c == EOF
  return ((c >= 'a' && c <= 'z') || (c >= '0' && c <= '9') ||
    (c >= 'A' && c <= 'Z') || c == '_' || c == '$' ||
      c == '\\' || c[0] > 126)
end

#jsmin ⇒ Object

jsmin – Copy the input to the output, deleting the characters which are insignificant to JavaScript. Comments will be removed. Tabs will be replaced with spaces. Carriage returns will be replaced with linefeeds. Most spaces and linefeeds will be removed.



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# File 'lib/smurf/javascript.rb', line 169

def jsmin
  @theA = "\n"
  action(3)
  while (@theA != EOF)
    case @theA
    when " "
      if (isAlphanum(@theB))
        action(1)
      else
        action(2)
      end
    when "\n"
      case (@theB)
      when "{","[","(","+","-"
        action(1)
      when " "
        action(3)
      else
        if (isAlphanum(@theB))
          action(1)
        else
          action(2)
        end
      end
    else
      case (@theB)
      when " "
        if (isAlphanum(@theA))
          action(1)
        else
          action(3)
        end
      when "\n"
        case (@theA)
        when "}","]",")","+","-","\"","\\", "'", '"'
          action(1)
        else
          if (isAlphanum(@theA))
            action(1)
          else
            action(3)
          end
        end
      else
        action(1)
      end
    end
  end
end

#minified ⇒ Object 



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# File 'lib/smurf/javascript.rb', line 52

def minified
  @output.rewind
  @output.read
end

#mynext ⇒ Object

mynext – get the next character, excluding comments. peek() is used to see if a ‘/’ is followed by a ‘/’ or ‘*’.



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# File 'lib/smurf/javascript.rb', line 86

def mynext()
  c = get
  if (c == "/")
    if(peek == "/")
      while(true)
        c = get
        if (c <= "\n")
        return c
        end
      end
    end
    if(peek == "*")
      get
      while(true)
        case get
        when "*"
         if (peek == "/")
            get
            return " "
          end
        when EOF
          raise "Unterminated comment"
        end
      end
    end
  end
  return c
end

#peek ⇒ Object

Get the next character without getting it.



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# File 'lib/smurf/javascript.rb', line 78

def peek()
  lookaheadChar = @input.getc
  @input.ungetc(lookaheadChar)
  return lookaheadChar.chr
end