Class: Parser::Source::Rewriter

Inherits:
Object
  • Object
show all
Defined in:
lib/parser/source/rewriter.rb

Defined Under Namespace

Classes: Action

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(source_buffer) ⇒ Rewriter

Returns a new instance of Rewriter.



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# File 'lib/parser/source/rewriter.rb', line 7

def initialize(source_buffer)
  @diagnostics = Diagnostic::Engine.new
  @diagnostics.consumer = lambda do |diag|
    $stderr.puts diag.render
  end

  @source_buffer = source_buffer
  @queue         = []
  @clobber       = 0
end

Instance Attribute Details

#diagnostics ⇒ Object

Returns the value of attribute diagnostics.



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# File 'lib/parser/source/rewriter.rb', line 5

def diagnostics
  @diagnostics
end

Instance Method Details

#append(action) ⇒ Object (private) 



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# File 'lib/parser/source/rewriter.rb', line 53

def append(action)
  if (clobber_action = clobbered?(action.range))
    # cannot replace 3 characters with "foobar"
    diagnostic = Diagnostic.new(:error,
                                "cannot #{action}",
                                action.range)
    @diagnostics.process(diagnostic)

    # clobbered by: remove 3 characters
    diagnostic = Diagnostic.new(:note,
                                "clobbered by: #{clobber_action}",
                                clobber_action.range)
    @diagnostics.process(diagnostic)
  else
    clobber(action.range)

    @queue << action
  end

  self
end

#clobber(range) ⇒ Object (private) 



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# File 'lib/parser/source/rewriter.rb', line 75

def clobber(range)
  @clobber |= (2 ** range.size - 1) << range.begin_pos
end

#clobbered?(range) ⇒ Boolean (private)

Returns:

  • (Boolean) 


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# File 'lib/parser/source/rewriter.rb', line 79

def clobbered?(range)
  if @clobber & ((2 ** range.size - 1) << range.begin_pos) != 0
    @queue.find do |action|
      action.range.to_a & range.to_a
    end
  end
end

#insert_after(range, content) ⇒ Object 



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# File 'lib/parser/source/rewriter.rb', line 26

def insert_after(range, content)
  append Rewriter::Action.new(range.end, content)
end

#insert_before(range, content) ⇒ Object 



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# File 'lib/parser/source/rewriter.rb', line 22

def insert_before(range, content)
  append Rewriter::Action.new(range.begin, content)
end

#process ⇒ Object 



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# File 'lib/parser/source/rewriter.rb', line 34

def process
  adjustment = 0
  source     = @source_buffer.source.dup

  @queue.sort_by { |action| action.range.begin_pos }.
         each do |action|
    begin_pos = action.range.begin_pos + adjustment
    end_pos   = begin_pos + action.range.length

    source[begin_pos...end_pos] = action.replacement

    adjustment += (action.replacement.length - action.range.length)
  end

  source
end

#remove(range) ⇒ Object 



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# File 'lib/parser/source/rewriter.rb', line 18

def remove(range)
  append Rewriter::Action.new(range, "")
end

#replace(range, content) ⇒ Object 



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# File 'lib/parser/source/rewriter.rb', line 30

def replace(range, content)
  append Rewriter::Action.new(range, content)
end