class ActionView::Template

def compile(mod)

regardless of the original source encoding.
In general, this means that templates will be UTF-8 inside of Rails,
encode the source into Encoding.default_internal.
Otherwise, after we figure out the correct encoding, we then

specifying the encoding. For instance, ERB supports <%# encoding: %>
the template engine to support additional mechanisms for
String to the engine without further processing. This allows
If the template engine handles encodings, we send the encoded

the encoding of the compiled template.
Among other things, this method is responsible for properly setting 
def compile(mod)
  begin
    mod.module_eval(compiled_source, identifier, offset)
  rescue SyntaxError
    # Account for when code in the template is not syntactically valid; e.g. if we're using
    # ERB and the user writes <%= foo( %>, attempting to call a helper `foo` and interpolate
    # the result into the template, but missing an end parenthesis.
    raise SyntaxErrorInTemplate.new(self, encode!)
  end
  return unless strict_locals?
  parameters = mod.instance_method(method_name).parameters
  parameters -= [[:req, :local_assigns], [:req, :output_buffer]]
  # Check compiled method parameters to ensure that only kwargs
  # were provided as strict locals, preventing `locals: (foo, *foo)` etc
  # and allowing `locals: (foo:)`.
  non_kwarg_parameters = parameters.select do |parameter|
    ![:keyreq, :key, :keyrest, :nokey].include?(parameter[0])
  end
  non_kwarg_parameters.pop if non_kwarg_parameters.last == %i(block _)
  unless non_kwarg_parameters.empty?
    mod.undef_method(method_name)
    raise ArgumentError.new(
      "#{non_kwarg_parameters.map { |_, name| "`#{name}`" }.to_sentence} set as non-keyword " \
      "#{'argument'.pluralize(non_kwarg_parameters.length)} for #{short_identifier}. " \
      "Locals can only be set as keyword arguments."
    )
  end
  unless parameters.any? { |type, _| type == :keyrest }
    parameters.map!(&:last)
    parameters.sort!
    @strict_local_keys = parameters.freeze
  end
end