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Diffstat (limited to 'lib/error_highlight/base.rb')
| -rw-r--r-- | lib/error_highlight/base.rb | 938 |
1 files changed, 938 insertions, 0 deletions
diff --git a/lib/error_highlight/base.rb b/lib/error_highlight/base.rb new file mode 100644 index 0000000000..5fffe5ec34 --- /dev/null +++ b/lib/error_highlight/base.rb @@ -0,0 +1,938 @@ +require_relative "version" + +module ErrorHighlight + # Identify the code fragment where a given exception occurred. + # + # Options: + # + # point_type: :name | :args + # :name (default) points to the method/variable name where the exception occurred. + # :args points to the arguments of the method call where the exception occurred. + # + # backtrace_location: Thread::Backtrace::Location + # It locates the code fragment of the given backtrace_location. + # By default, it uses the first frame of backtrace_locations of the given exception. + # + # Returns: + # { + # first_lineno: Integer, + # first_column: Integer, + # last_lineno: Integer, + # last_column: Integer, + # snippet: String, + # script_lines: [String], + # } | nil + # + # Limitations: + # + # Currently, ErrorHighlight.spot only supports a single-line code fragment. + # Therefore, if the return value is not nil, first_lineno and last_lineno will have + # the same value. If the relevant code fragment spans multiple lines + # (e.g., Array#[] of <tt>ary[(newline)expr(newline)]</tt>), the method will return nil. + # This restriction may be removed in the future. + def self.spot(obj, **opts) + case obj + when Exception + exc = obj + loc = opts[:backtrace_location] + opts = { point_type: opts.fetch(:point_type, :name) } + + unless loc + case exc + when TypeError, ArgumentError + opts[:point_type] = :args + end + + locs = exc.backtrace_locations + return nil unless locs + + loc = locs.first + return nil unless loc + + opts[:name] = exc.name if NameError === obj + end + + return nil unless Thread::Backtrace::Location === loc + + node = + begin + RubyVM::AbstractSyntaxTree.of(loc, keep_script_lines: true) + rescue RuntimeError => error + # RubyVM::AbstractSyntaxTree.of raises an error with a message that + # includes "prism" when the ISEQ was compiled with the prism compiler. + # In this case, we'll try to parse again with prism instead. + raise unless error.message.include?("prism") + prism_find(loc) + end + + Spotter.new(node, **opts).spot + + when RubyVM::AbstractSyntaxTree::Node, Prism::Node + Spotter.new(obj, **opts).spot + + else + raise TypeError, "Exception is expected" + end + + rescue SyntaxError, + SystemCallError, # file not found or something + ArgumentError # eval'ed code + + return nil + end + + # Accepts a Thread::Backtrace::Location object and returns a Prism::Node + # corresponding to the backtrace location in the source code. + def self.prism_find(location) + require "prism" + return nil if Prism::VERSION < "1.0.0" + + absolute_path = location.absolute_path + return unless absolute_path + + node_id = RubyVM::AbstractSyntaxTree.node_id_for_backtrace_location(location) + Prism.parse_file(absolute_path).value.breadth_first_search { |node| node.node_id == node_id } + end + + private_class_method :prism_find + + class Spotter + class NonAscii < Exception; end + private_constant :NonAscii + + def initialize(node, point_type: :name, name: nil) + @node = node + @point_type = point_type + @name = name + + # Not-implemented-yet options + @arg = nil # Specify the index or keyword at which argument caused the TypeError/ArgumentError + @multiline = false # Allow multiline spot + + @fetch = -> (lineno, last_lineno = lineno) do + snippet = @node.script_lines[lineno - 1 .. last_lineno - 1].join("") + snippet += "\n" unless snippet.end_with?("\n") + + # It requires some work to support Unicode (or multibyte) characters. + # Tentatively, we stop highlighting if the code snippet has non-ascii characters. + # See https://github.com/ruby/error_highlight/issues/4 + raise NonAscii unless snippet.ascii_only? + + snippet + end + end + + def spot + return nil unless @node + + # In Ruby 3.2 or later, a nested constant access (like `Foo::Bar::Baz`) + # is compiled to one instruction (opt_getconstant_path). + # @node points to the node of the whole `Foo::Bar::Baz` even if `Foo` + # or `Foo::Bar` causes NameError. + # So we try to spot the sub-node that causes the NameError by using + # `NameError#name`. + case @node.type + when :COLON2 + subnodes = [] + node = @node + while node.type == :COLON2 + node2, const = node.children + subnodes << node if const == @name + node = node2 + end + if node.type == :CONST || node.type == :COLON3 + if node.children.first == @name + subnodes << node + end + + # If we found only one sub-node whose name is equal to @name, use it + return nil if subnodes.size != 1 + @node = subnodes.first + else + # Do nothing; opt_getconstant_path is used only when the const base is + # NODE_CONST (`Foo`) or NODE_COLON3 (`::Foo`) + end + when :constant_path_node + subnodes = [] + node = @node + + begin + subnodes << node if node.name == @name + end while (node = node.parent).is_a?(Prism::ConstantPathNode) + + if node.is_a?(Prism::ConstantReadNode) && node.name == @name + subnodes << node + end + + # If we found only one sub-node whose name is equal to @name, use it + return nil if subnodes.size != 1 + @node = subnodes.first + end + + case @node.type + + when :CALL, :QCALL + case @point_type + when :name + spot_call_for_name + when :args + spot_call_for_args + end + + when :ATTRASGN + case @point_type + when :name + spot_attrasgn_for_name + when :args + spot_attrasgn_for_args + end + + when :OPCALL + case @point_type + when :name + spot_opcall_for_name + when :args + spot_opcall_for_args + end + + when :FCALL + case @point_type + when :name + spot_fcall_for_name + when :args + spot_fcall_for_args + end + + when :VCALL + spot_vcall + + when :OP_ASGN1 + case @point_type + when :name + spot_op_asgn1_for_name + when :args + spot_op_asgn1_for_args + end + + when :OP_ASGN2 + case @point_type + when :name + spot_op_asgn2_for_name + when :args + spot_op_asgn2_for_args + end + + when :CONST + spot_vcall + + when :COLON2 + spot_colon2 + + when :COLON3 + spot_vcall + + when :OP_CDECL + spot_op_cdecl + + when :DEFN + raise NotImplementedError if @point_type != :name + spot_defn + + when :DEFS + raise NotImplementedError if @point_type != :name + spot_defs + + when :LAMBDA + spot_lambda + + when :ITER + spot_iter + + when :call_node + case @point_type + when :name + prism_spot_call_for_name + when :args + prism_spot_call_for_args + end + + when :local_variable_operator_write_node + case @point_type + when :name + prism_spot_local_variable_operator_write_for_name + when :args + prism_spot_local_variable_operator_write_for_args + end + + when :call_operator_write_node + case @point_type + when :name + prism_spot_call_operator_write_for_name + when :args + prism_spot_call_operator_write_for_args + end + + when :index_operator_write_node + case @point_type + when :name + prism_spot_index_operator_write_for_name + when :args + prism_spot_index_operator_write_for_args + end + + when :constant_read_node + prism_spot_constant_read + + when :constant_path_node + prism_spot_constant_path + + when :constant_path_operator_write_node + prism_spot_constant_path_operator_write + + when :def_node + case @point_type + when :name + prism_spot_def_for_name + when :args + raise NotImplementedError + end + + when :lambda_node + case @point_type + when :name + prism_spot_lambda_for_name + when :args + raise NotImplementedError + end + + when :block_node + case @point_type + when :name + prism_spot_block_for_name + when :args + raise NotImplementedError + end + + end + + if @snippet && @beg_column && @end_column && @beg_column < @end_column + return { + first_lineno: @beg_lineno, + first_column: @beg_column, + last_lineno: @end_lineno, + last_column: @end_column, + snippet: @snippet, + script_lines: @node.script_lines, + } + else + return nil + end + + rescue NonAscii + nil + end + + private + + # Example: + # x.foo + # ^^^^ + # x.foo(42) + # ^^^^ + # x&.foo + # ^^^^^ + # x[42] + # ^^^^ + # x += 1 + # ^ + def spot_call_for_name + nd_recv, mid, nd_args = @node.children + lineno = nd_recv.last_lineno + lines = @fetch[lineno, @node.last_lineno] + if mid == :[] && lines.match(/\G[\s)]*(\[(?:\s*\])?)/, nd_recv.last_column) + @beg_column = $~.begin(1) + @snippet = lines[/.*\n/] + @beg_lineno = @end_lineno = lineno + if nd_args + if nd_recv.last_lineno == nd_args.last_lineno && @snippet.match(/\s*\]/, nd_args.last_column) + @end_column = $~.end(0) + end + else + if lines.match(/\G[\s)]*?\[\s*\]/, nd_recv.last_column) + @end_column = $~.end(0) + end + end + elsif lines.match(/\G[\s)]*?(\&?\.)(\s*?)(#{ Regexp.quote(mid) }).*\n/, nd_recv.last_column) + lines = $` + $& + @beg_column = $~.begin($2.include?("\n") ? 3 : 1) + @end_column = $~.end(3) + if i = lines[..@beg_column].rindex("\n") + @beg_lineno = @end_lineno = lineno + lines[..@beg_column].count("\n") + @snippet = lines[i + 1..] + @beg_column -= i + 1 + @end_column -= i + 1 + else + @snippet = lines + @beg_lineno = @end_lineno = lineno + end + elsif mid.to_s =~ /\A\W+\z/ && lines.match(/\G\s*(#{ Regexp.quote(mid) })=.*\n/, nd_recv.last_column) + @snippet = $` + $& + @beg_lineno = @end_lineno = lineno + @beg_column = $~.begin(1) + @end_column = $~.end(1) + end + end + + # Example: + # x.foo(42) + # ^^ + # x[42] + # ^^ + # x += 1 + # ^ + def spot_call_for_args + _nd_recv, _mid, nd_args = @node.children + if nd_args && nd_args.first_lineno == nd_args.last_lineno + fetch_line(nd_args.first_lineno) + @beg_column = nd_args.first_column + @end_column = nd_args.last_column + end + # TODO: support @arg + end + + # Example: + # x.foo = 1 + # ^^^^^^ + # x[42] = 1 + # ^^^^^^ + def spot_attrasgn_for_name + nd_recv, mid, nd_args = @node.children + *nd_args, _nd_last_arg, _nil = nd_args.children + fetch_line(nd_recv.last_lineno) + if mid == :[]= && @snippet.match(/\G[\s)]*(\[)/, nd_recv.last_column) + @beg_column = $~.begin(1) + args_last_column = $~.end(0) + if nd_args.last && nd_recv.last_lineno == nd_args.last.last_lineno + args_last_column = nd_args.last.last_column + end + if @snippet.match(/[\s)]*\]\s*=/, args_last_column) + @end_column = $~.end(0) + end + elsif @snippet.match(/\G[\s)]*(\.\s*#{ Regexp.quote(mid.to_s.sub(/=\z/, "")) }\s*=)/, nd_recv.last_column) + @beg_column = $~.begin(1) + @end_column = $~.end(1) + end + end + + # Example: + # x.foo = 1 + # ^ + # x[42] = 1 + # ^^^^^^^ + # x[] = 1 + # ^^^^^ + def spot_attrasgn_for_args + nd_recv, mid, nd_args = @node.children + fetch_line(nd_recv.last_lineno) + if mid == :[]= && @snippet.match(/\G[\s)]*\[/, nd_recv.last_column) + @beg_column = $~.end(0) + if nd_recv.last_lineno == nd_args.last_lineno + @end_column = nd_args.last_column + end + elsif nd_args && nd_args.first_lineno == nd_args.last_lineno + @beg_column = nd_args.first_column + @end_column = nd_args.last_column + end + # TODO: support @arg + end + + # Example: + # x + 1 + # ^ + # +x + # ^ + def spot_opcall_for_name + nd_recv, op, nd_arg = @node.children + fetch_line(nd_recv.last_lineno) + if nd_arg + # binary operator + if @snippet.match(/\G[\s)]*(#{ Regexp.quote(op) })/, nd_recv.last_column) + @beg_column = $~.begin(1) + @end_column = $~.end(1) + end + else + # unary operator + if @snippet[...nd_recv.first_column].match(/(#{ Regexp.quote(op.to_s.sub(/@\z/, "")) })\s*\(?\s*\z/) + @beg_column = $~.begin(1) + @end_column = $~.end(1) + end + end + end + + # Example: + # x + 1 + # ^ + def spot_opcall_for_args + _nd_recv, _op, nd_arg = @node.children + if nd_arg && nd_arg.first_lineno == nd_arg.last_lineno + # binary operator + fetch_line(nd_arg.first_lineno) + @beg_column = nd_arg.first_column + @end_column = nd_arg.last_column + end + end + + # Example: + # foo(42) + # ^^^ + # foo 42 + # ^^^ + def spot_fcall_for_name + mid, _nd_args = @node.children + fetch_line(@node.first_lineno) + if @snippet.match(/(#{ Regexp.quote(mid) })/, @node.first_column) + @beg_column = $~.begin(1) + @end_column = $~.end(1) + end + end + + # Example: + # foo(42) + # ^^ + # foo 42 + # ^^ + def spot_fcall_for_args + _mid, nd_args = @node.children + if nd_args && nd_args.first_lineno == nd_args.last_lineno + fetch_line(nd_args.first_lineno) + @beg_column = nd_args.first_column + @end_column = nd_args.last_column + end + end + + # Example: + # foo + # ^^^ + def spot_vcall + if @node.first_lineno == @node.last_lineno + fetch_line(@node.last_lineno) + @beg_column = @node.first_column + @end_column = @node.last_column + end + end + + # Example: + # x[1] += 42 + # ^^^ (for []) + # x[1] += 42 + # ^ (for +) + # x[1] += 42 + # ^^^^^^ (for []=) + def spot_op_asgn1_for_name + nd_recv, op, nd_args, _nd_rhs = @node.children + fetch_line(nd_recv.last_lineno) + if @snippet.match(/\G[\s)]*(\[)/, nd_recv.last_column) + bracket_beg_column = $~.begin(1) + args_last_column = $~.end(0) + if nd_args && nd_recv.last_lineno == nd_args.last_lineno + args_last_column = nd_args.last_column + end + if @snippet.match(/\s*\](\s*)(#{ Regexp.quote(op) })=()/, args_last_column) + case @name + when :[], :[]= + @beg_column = bracket_beg_column + @end_column = $~.begin(@name == :[] ? 1 : 3) + when op + @beg_column = $~.begin(2) + @end_column = $~.end(2) + end + end + end + end + + # Example: + # x[1] += 42 + # ^^^^^^^^ + def spot_op_asgn1_for_args + nd_recv, mid, nd_args, nd_rhs = @node.children + fetch_line(nd_recv.last_lineno) + if mid == :[]= && @snippet.match(/\G\s*\[/, nd_recv.last_column) + @beg_column = $~.end(0) + if nd_recv.last_lineno == nd_rhs.last_lineno + @end_column = nd_rhs.last_column + end + elsif nd_args && nd_args.first_lineno == nd_rhs.last_lineno + @beg_column = nd_args.first_column + @end_column = nd_rhs.last_column + end + # TODO: support @arg + end + + # Example: + # x.foo += 42 + # ^^^ (for foo) + # x.foo += 42 + # ^ (for +) + # x.foo += 42 + # ^^^^^^^ (for foo=) + def spot_op_asgn2_for_name + nd_recv, _qcall, attr, op, _nd_rhs = @node.children + fetch_line(nd_recv.last_lineno) + if @snippet.match(/\G[\s)]*(\.)\s*#{ Regexp.quote(attr) }()\s*(#{ Regexp.quote(op) })(=)/, nd_recv.last_column) + case @name + when attr + @beg_column = $~.begin(1) + @end_column = $~.begin(2) + when op + @beg_column = $~.begin(3) + @end_column = $~.end(3) + when :"#{ attr }=" + @beg_column = $~.begin(1) + @end_column = $~.end(4) + end + end + end + + # Example: + # x.foo += 42 + # ^^ + def spot_op_asgn2_for_args + _nd_recv, _qcall, _attr, _op, nd_rhs = @node.children + if nd_rhs.first_lineno == nd_rhs.last_lineno + fetch_line(nd_rhs.first_lineno) + @beg_column = nd_rhs.first_column + @end_column = nd_rhs.last_column + end + end + + # Example: + # Foo::Bar + # ^^^^^ + def spot_colon2 + nd_parent, const = @node.children + if nd_parent.last_lineno == @node.last_lineno + fetch_line(nd_parent.last_lineno) + @beg_column = nd_parent.last_column + @end_column = @node.last_column + else + fetch_line(@node.last_lineno) + if @snippet[...@node.last_column].match(/#{ Regexp.quote(const) }\z/) + @beg_lineno = @end_lineno = @node.last_lineno + @beg_column = $~.begin(0) + @end_column = $~.end(0) + end + end + end + + # Example: + # Foo::Bar += 1 + # ^^^^^^^^ + def spot_op_cdecl + nd_lhs, op, _nd_rhs = @node.children + *nd_parent_lhs, _const = nd_lhs.children + if @name == op + fetch_line(nd_lhs.last_lineno) + if @snippet.match(/\G\s*(#{ Regexp.quote(op) })=/, nd_lhs.last_column) + @beg_column = $~.begin(1) + @end_column = $~.end(1) + end + else + # constant access error + @end_column = nd_lhs.last_column + if nd_parent_lhs.empty? # example: ::C += 1 + if nd_lhs.first_lineno == nd_lhs.last_lineno + fetch_line(nd_lhs.last_lineno) + @beg_column = nd_lhs.first_column + end + else # example: Foo::Bar::C += 1 + if nd_parent_lhs.last.last_lineno == nd_lhs.last_lineno + fetch_line(nd_lhs.last_lineno) + @beg_column = nd_parent_lhs.last.last_column + end + end + end + end + + # Example: + # def bar; end + # ^^^ + def spot_defn + mid, = @node.children + fetch_line(@node.first_lineno) + if @snippet.match(/\Gdef\s+(#{ Regexp.quote(mid) }\b)/, @node.first_column) + @beg_column = $~.begin(1) + @end_column = $~.end(1) + end + end + + # Example: + # def Foo.bar; end + # ^^^^ + def spot_defs + nd_recv, mid, = @node.children + fetch_line(nd_recv.last_lineno) + if @snippet.match(/\G\s*(\.\s*#{ Regexp.quote(mid) }\b)/, nd_recv.last_column) + @beg_column = $~.begin(1) + @end_column = $~.end(1) + end + end + + # Example: + # -> { ... } + # ^^ + def spot_lambda + fetch_line(@node.first_lineno) + if @snippet.match(/\G->/, @node.first_column) + @beg_column = $~.begin(0) + @end_column = $~.end(0) + end + end + + # Example: + # lambda { ... } + # ^ + # define_method :foo do + # ^^ + def spot_iter + _nd_fcall, nd_scope = @node.children + fetch_line(nd_scope.first_lineno) + if @snippet.match(/\G(?:do\b|\{)/, nd_scope.first_column) + @beg_column = $~.begin(0) + @end_column = $~.end(0) + end + end + + def fetch_line(lineno) + @beg_lineno = @end_lineno = lineno + @snippet = @fetch[lineno] + end + + # Take a location from the prism parser and set the necessary instance + # variables. + def prism_location(location) + @beg_lineno = location.start_line + @beg_column = location.start_column + @end_lineno = location.end_line + @end_column = location.end_column + @snippet = @fetch[@beg_lineno, @end_lineno] + end + + # Example: + # x.foo + # ^^^^ + # x.foo(42) + # ^^^^ + # x&.foo + # ^^^^^ + # x[42] + # ^^^^ + # x.foo = 1 + # ^^^^^^ + # x[42] = 1 + # ^^^^^^ + # x + 1 + # ^ + # +x + # ^ + # foo(42) + # ^^^ + # foo 42 + # ^^^ + # foo + # ^^^ + def prism_spot_call_for_name + # Explicitly turn off foo.() syntax because error_highlight expects this + # to not work. + return nil if @node.name == :call && @node.message_loc.nil? + + location = @node.message_loc || @node.call_operator_loc || @node.location + location = @node.call_operator_loc.join(location) if @node.call_operator_loc&.start_line == location.start_line + + # If the method name ends with "=" but the message does not, then this is + # a method call using the "attribute assignment" syntax + # (e.g., foo.bar = 1). In this case we need to go retrieve the = sign and + # add it to the location. + if (name = @node.name).end_with?("=") && !@node.message.end_with?("=") + location = location.adjoin("=") + end + + prism_location(location) + + if !name.end_with?("=") && !name.match?(/[[:alpha:]_\[]/) + # If the method name is an operator, then error_highlight only + # highlights the first line. + fetch_line(location.start_line) + end + end + + # Example: + # x.foo(42) + # ^^ + # x[42] + # ^^ + # x.foo = 1 + # ^ + # x[42] = 1 + # ^^^^^^^ + # x[] = 1 + # ^^^^^ + # x + 1 + # ^ + # foo(42) + # ^^ + # foo 42 + # ^^ + def prism_spot_call_for_args + # Disallow highlighting arguments if there are no arguments. + return if @node.arguments.nil? + + # Explicitly turn off foo.() syntax because error_highlight expects this + # to not work. + return nil if @node.name == :call && @node.message_loc.nil? + + if @node.name == :[]= && @node.opening == "[" && (@node.arguments&.arguments || []).length == 1 + prism_location(@node.opening_loc.copy(start_offset: @node.opening_loc.start_offset + 1).join(@node.arguments.location)) + else + prism_location(@node.arguments.location) + end + end + + # Example: + # x += 1 + # ^ + def prism_spot_local_variable_operator_write_for_name + prism_location(@node.binary_operator_loc.chop) + end + + # Example: + # x += 1 + # ^ + def prism_spot_local_variable_operator_write_for_args + prism_location(@node.value.location) + end + + # Example: + # x.foo += 42 + # ^^^ (for foo) + # x.foo += 42 + # ^ (for +) + # x.foo += 42 + # ^^^^^^^ (for foo=) + def prism_spot_call_operator_write_for_name + if !@name.start_with?(/[[:alpha:]_]/) + prism_location(@node.binary_operator_loc.chop) + else + location = @node.message_loc + if @node.call_operator_loc.start_line == location.start_line + location = @node.call_operator_loc.join(location) + end + + location = location.adjoin("=") if @name.end_with?("=") + prism_location(location) + end + end + + # Example: + # x.foo += 42 + # ^^ + def prism_spot_call_operator_write_for_args + prism_location(@node.value.location) + end + + # Example: + # x[1] += 42 + # ^^^ (for []) + # x[1] += 42 + # ^ (for +) + # x[1] += 42 + # ^^^^^^ (for []=) + def prism_spot_index_operator_write_for_name + case @name + when :[] + prism_location(@node.opening_loc.join(@node.closing_loc)) + when :[]= + prism_location(@node.opening_loc.join(@node.closing_loc).adjoin("=")) + else + # Explicitly turn off foo[] += 1 syntax when the operator is not on + # the same line because error_highlight expects this to not work. + return nil if @node.binary_operator_loc.start_line != @node.opening_loc.start_line + + prism_location(@node.binary_operator_loc.chop) + end + end + + # Example: + # x[1] += 42 + # ^^^^^^^^ + def prism_spot_index_operator_write_for_args + opening_loc = + if @node.arguments.nil? + @node.opening_loc.copy(start_offset: @node.opening_loc.start_offset + 1) + else + @node.arguments.location + end + + prism_location(opening_loc.join(@node.value.location)) + end + + # Example: + # Foo + # ^^^ + def prism_spot_constant_read + prism_location(@node.location) + end + + # Example: + # Foo::Bar + # ^^^^^ + def prism_spot_constant_path + if @node.parent && @node.parent.location.end_line == @node.location.end_line + fetch_line(@node.parent.location.end_line) + prism_location(@node.delimiter_loc.join(@node.name_loc)) + else + fetch_line(@node.location.end_line) + location = @node.name_loc + location = @node.delimiter_loc.join(location) if @node.delimiter_loc.end_line == location.start_line + prism_location(location) + end + end + + # Example: + # Foo::Bar += 1 + # ^^^^^^^^ + def prism_spot_constant_path_operator_write + if @name == (target = @node.target).name + prism_location(target.delimiter_loc.join(target.name_loc)) + else + prism_location(@node.binary_operator_loc.chop) + end + end + + # Example: + # def foo() + # ^^^ + def prism_spot_def_for_name + location = @node.name_loc + location = @node.operator_loc.join(location) if @node.operator_loc + prism_location(location) + end + + # Example: + # -> x, y { } + # ^^ + def prism_spot_lambda_for_name + prism_location(@node.operator_loc) + end + + # Example: + # lambda { } + # ^ + # define_method :foo do |x, y| + # ^ + def prism_spot_block_for_name + prism_location(@node.opening_loc) + end + end + + private_constant :Spotter +end |