Class: RubyLexUtils

Inherits:
Object show all
Defined in:
lib/cosmos/utilities/ruby_lex_utils.rb

Constant Summary collapse

BLANK_LINE_REGEX =

Regular expression to detect blank lines

/^\s*$/
LONELY_ELSE_REGEX =

Regular expression to detect lines containing only ‘else’

/^\s*else\s*$/
KEYWORD_TOKENS =

Ruby keywords

[RubyToken::TkCLASS,
RubyToken::TkMODULE,
RubyToken::TkDEF,
RubyToken::TkUNDEF,
RubyToken::TkBEGIN,
RubyToken::TkRESCUE,
RubyToken::TkENSURE,
RubyToken::TkEND,
RubyToken::TkIF,
RubyToken::TkUNLESS,
RubyToken::TkTHEN,
RubyToken::TkELSIF,
RubyToken::TkELSE,
RubyToken::TkCASE,
RubyToken::TkWHEN,
RubyToken::TkWHILE,
RubyToken::TkUNTIL,
RubyToken::TkFOR,
RubyToken::TkBREAK,
RubyToken::TkNEXT,
RubyToken::TkREDO,
RubyToken::TkRETRY,
RubyToken::TkIN,
RubyToken::TkDO,
RubyToken::TkRETURN,
RubyToken::TkIF_MOD,
RubyToken::TkUNLESS_MOD,
RubyToken::TkWHILE_MOD,
RubyToken::TkUNTIL_MOD,
RubyToken::TkALIAS,
RubyToken::TklBEGIN,
RubyToken::TklEND,
RubyToken::TkfLBRACE]
BLOCK_BEGINNING_TOKENS =

Ruby keywords which define the beginning of a block: do, {, begin

[RubyToken::TkDO,
RubyToken::TkfLBRACE,
RubyToken::TkBEGIN]

Instance Method Summary collapse

Constructor Details

#initialize ⇒ RubyLexUtils

Create a new RubyLex and StringIO to hold the text to operate on



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# File 'lib/cosmos/utilities/ruby_lex_utils.rb', line 137

def initialize
  @lex    = RubyLex.new
  @lex_io = StringIO.new('')
end

Instance Method Details

#contains_begin?(text) ⇒ Boolean

Returns Whether the text contains the ‘begin’ keyword.

Parameters:

Returns:

  • Whether the text contains the 'begin' keyword



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# File 'lib/cosmos/utilities/ruby_lex_utils.rb', line 144

def contains_begin?(text)
  @lex.reinitialize
  @lex.exception_on_syntax_error = false
  @lex_io.string = text
  @lex.set_input(@lex_io)
  while token = @lex.token
    if token.class == RubyToken::TkBEGIN
      return true
    end
  end
  return false
end

#contains_block_beginning?(text) ⇒ Boolean

Returns Whether the text contains a keyword which starts a block. i.e. ‘do’, ‘{’, or ‘begin’.

Parameters:

Returns:

  • Whether the text contains a keyword which starts a block. i.e. 'do', '{', or 'begin'



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# File 'lib/cosmos/utilities/ruby_lex_utils.rb', line 175

def contains_block_beginning?(text)
  @lex.reinitialize
  @lex.exception_on_syntax_error = false
  @lex_io.string = text
  @lex.set_input(@lex_io)
  while token = @lex.token
    if BLOCK_BEGINNING_TOKENS.include?(token.class)
      return true
    end
  end
  return false
end

#contains_keyword?(text) ⇒ Boolean

Returns Whether the text contains a Ruby keyword.

Parameters:

Returns:

  • Whether the text contains a Ruby keyword



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# File 'lib/cosmos/utilities/ruby_lex_utils.rb', line 159

def contains_keyword?(text)
  @lex.reinitialize
  @lex.exception_on_syntax_error = false
  @lex_io.string = text
  @lex.set_input(@lex_io)
  while token = @lex.token
    if KEYWORD_TOKENS.include?(token.class)
      return true
    end
  end
  return false
end

#each_lexed_segment(text) {|line, instrumentable, inside_begin, line_no| ... } ⇒ Object

Yields each lexed segment and if the segment is instrumentable

Yield Parameters:

  • line (String) —

    The entire line

  • instrumentable (Boolean) —

    Whether the line is instrumentable

  • inside_begin (Integer) —

    The level of indentation

  • line_no (Integer) —

    The current line number

Parameters:



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# File 'lib/cosmos/utilities/ruby_lex_utils.rb', line 244

def each_lexed_segment(text)
  lex = RubyLex.new
  lex.exception_on_syntax_error = false
  lex_io = StringIO.new(text)
  lex.set_input(lex_io)

  while lexed = lex.lex
    line_no = lex.exp_line_no

    if contains_begin?(lexed)
      inside_begin = lex.indent - 1
    end

    if lex.indent == inside_begin
      inside_begin = nil
    end

    loop do # loop to allow restarting for nested conditions

      # Yield blank lines and lonely else lines before the actual line
      while (index = lexed.index("\n"))
        line = lexed[0..index]
        if line =~ BLANK_LINE_REGEX
          yield line, true, inside_begin, line_no
          line_no += 1
          lexed = lexed[(index + 1)..-1]
        elsif line =~ LONELY_ELSE_REGEX
          yield line, false, inside_begin, line_no
          line_no += 1
          lexed = lexed[(index + 1)..-1]
        else
          break
        end
      end

      if contains_keyword?(lexed)
        if contains_block_beginning?(lexed)
          section = ''
          lexed.each_line do |lexed_part|
            section << lexed_part
            if contains_block_beginning?(section)
              yield section, false, inside_begin, line_no
              break
            end
            line_no += 1
          end
          line_no += 1
          remainder = lexed[(section.length)..-1]
          lexed = remainder
          next unless remainder.empty?
        else
          yield lexed, false, inside_begin, line_no
        end
      elsif !lexed.empty?
        num_left_brackets  = lexed.count('{')
        num_right_brackets = lexed.count('}')
        if num_left_brackets != num_right_brackets
          # Don't instrument lines with unequal numbers of { and } brackets
          yield lexed, false, inside_begin, line_no
        else
          yield lexed, true, inside_begin, line_no
        end
      end
      lex.exp_line_no = lex.line_no
      break
    end # loop do
  end # while lexed
end

#remove_comments(text, progress_dialog = nil) ⇒ String

Returns The text with all comments removed.

Parameters:

  • (defaults to: nil)

    If this is set, the overall progress will be set as the processing progresses

Returns:

  • The text with all comments removed



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# File 'lib/cosmos/utilities/ruby_lex_utils.rb', line 192

def remove_comments(text, progress_dialog = nil)
  comments_removed = text.clone
  @lex.reinitialize
  @lex.exception_on_syntax_error = false
  @lex_io.string = text
  @lex.set_input(@lex_io)
  need_remove = nil
  delete_ranges = []
  token_count = 0
  progress = 0.0
  while token = @lex.token
    token_count += 1
    if need_remove
      delete_ranges << (need_remove..(token.seek - 1))
      need_remove = nil
    end
    if token.class == RubyToken::TkCOMMENT
      need_remove = token.seek
    end
    if progress_dialog and token_count % 10000 == 0
      progress += 0.01
      progress = 0.0 if progress >= 0.99
      progress_dialog.set_overall_progress(progress)
    end
  end

  if need_remove
    delete_ranges << (need_remove..(text.length - 1))
    need_remove = nil
  end

  delete_count = 0
  delete_ranges.reverse_each do |range|
    delete_count += 1
    comments_removed[range] = ''
    if progress_dialog and delete_count % 10000 == 0
      progress += 0.01
      progress = 0.0 if progress >= 0.99
      progress_dialog.set_overall_progress(progress)
    end
  end

  return comments_removed
end