class Parser::TreeRewriter


@api public
describing rewriters in greater detail.
See also [a blog entry](whitequark.org/blog/2013/04/26/lets-play-with-ruby-code/)
inserting/replacing code so you’ll have to do this yourself.
Keep in mind that {Parser::TreeRewriter} does not take care of indentation when
end
puts ‘hello’
while true
This would result in the following Ruby code:
puts rewriter.rewrite(buffer, ast)
# Rewrite the AST, returns a String with the new form.
rewriter = RemoveDo.new
buffer = Parser::Source::Buffer.new(‘(example)’, source: code)
ast = Parser::CurrentRuby.parse code
EOF
end
puts ‘hello’
while true do
code = <<-EOF
end
end
end
remove(node.location.begin)
if node.location.begin.is?(‘do’)
# Check if the statement starts with “do”
def on_while(node)
class RemoveDo < Parser::TreeRewriter
require ‘parser/current’
You can do this as following:
For example, assume you want to remove ‘do` tokens from a while statement.
{Parser::Source::TreeRewriter}
existing ASTs. It’s built on top of {Parser::AST::Processor} and
{Parser::TreeRewriter} offers a basic API that makes it easy to rewrite
#

def assignment?(node)

Returns:
  • (Boolean) -

Parameters:
  • node (Parser::AST::Node) -- 
def assignment?(node)
  [:lvasgn, :ivasgn, :gvasgn, :cvasgn, :casgn].include?(node.type)
end

def insert_after(range, content)

Parameters:
  • content (String) --
  • range (Parser::Source::Range) -- 
def insert_after(range, content)
  @source_rewriter.insert_after(range, content)
end

def insert_before(range, content)

Parameters:
  • content (String) --
  • range (Parser::Source::Range) -- 
def insert_before(range, content)
  @source_rewriter.insert_before(range, content)
end

def remove(range)

Parameters:
  • range (Parser::Source::Range) -- 
def remove(range)
  @source_rewriter.remove(range)
end

def replace(range, content)

Parameters:
  • content (String) --
  • range (Parser::Source::Range) -- 
def replace(range, content)
  @source_rewriter.replace(range, content)
end

def rewrite(source_buffer,

Returns:
  • (String) -

Parameters:
  • crossing_deletions:, (Symbol) -- different_replacements:, swallowed_insertions:
  • ast (Parser::AST::Node) --
  • source_buffer (Parser::Source::Buffer) -- 
def rewrite(source_buffer,
            ast,
            **policy)
  @source_rewriter = Parser::Source::TreeRewriter.new(source_buffer, **policy)
  process(ast)
  @source_rewriter.process
end

def wrap(range, before, after)

Parameters:
  • content (String) --
  • range (Parser::Source::Range) -- 
def wrap(range, before, after)
  @source_rewriter.wrap(range, before, after)
end