Class: Fast::Rewriter

Inherits:
Parser::TreeRewriter
  • Object
show all
Defined in:
lib/fast.rb

Overview

Note:

the standalone class needs to combines #replace_on to properly generate the ‘on_<node-type>` methods depending on the expression being used.

Rewriter encapsulates #match_index to allow ExperimentFile#partial_replace in a ExperimentFile.

Examples:

Simple Rewriter

ast = Fast.ast("a = 1")
buffer = Parser::Source::Buffer.new('replacement')
buffer.source = ast.loc.expression.source
rewriter = Rewriter.new buffer
rewriter.search ='(lvasgn _ ...)'
rewriter.replacement =  -> (node) { replace(node.location.name, 'variable_renamed') }
rewriter.replace_on(:lvasgn)
rewriter.rewrite(buffer, ast) # => "variable_renamed = 1"

See Also:

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*args) ⇒ Rewriter

Returns a new instance of Rewriter.



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# File 'lib/fast.rb', line 289

def initialize(*args)
  super
  @match_index = 0
end

Instance Attribute Details

#buffer ⇒ Object

Returns the value of attribute buffer.



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# File 'lib/fast.rb', line 288

def buffer
  @buffer
end

#match_index ⇒ Integer (readonly)

Returns with occurrence index.

Returns:

  • (Integer) —

    with occurrence index



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# File 'lib/fast.rb', line 287

def match_index
  @match_index
end

#replacement ⇒ Object

Returns the value of attribute replacement.



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# File 'lib/fast.rb', line 288

def replacement
  @replacement
end

#search ⇒ Object

Returns the value of attribute search.



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# File 'lib/fast.rb', line 288

def search
  @search
end

Instance Method Details

#execute_replacement(node, captures) ⇒ Object

Execute #replacement block

Parameters:

  • node (Astrolabe::Node) —

    that will be yield in the replacement block

  • captures (Array<Object>, nil) —

    are yield if #replacement take second argument.



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# File 'lib/fast.rb', line 315

def execute_replacement(node, captures)
  if replacement.parameters.length == 1
    instance_exec node, &replacement
  else
    instance_exec node, captures, &replacement
  end
end

#match?(node) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/fast.rb', line 294

def match?(node)
  Fast.match?(search, node)
end

#replace_on(*types) ⇒ Object

Generate methods for all affected types.

See Also:



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# File 'lib/fast.rb', line 300

def replace_on(*types)
  types.map do |type|
    self.class.send :define_method, "on_#{type}" do |node|
      if captures = match?(node) # rubocop:disable Lint/AssignmentInCondition
        @match_index += 1
        execute_replacement(node, captures)
      end
      super(node)
    end
  end
end