diff options
| -rw-r--r-- | activesupport/lib/binding_of_caller.rb | 140 |
1 files changed, 72 insertions, 68 deletions
diff --git a/activesupport/lib/binding_of_caller.rb b/activesupport/lib/binding_of_caller.rb index 7d31672a91..f58e87796c 100644 --- a/activesupport/lib/binding_of_caller.rb +++ b/activesupport/lib/binding_of_caller.rb @@ -1,81 +1,85 @@ begin require 'simplecc' rescue LoadError - def Continuation.create(*args, &block) #:nodoc: - cc = nil; result = callcc {|c| cc = c; block.call(cc) if block and args.empty?} - result ||= args - return *[cc, *result] + class Continuation #:nodoc: + def create(*args, &block) + cc = nil; result = callcc {|c| cc = c; block.call(cc) if block and args.empty?} + result ||= args + return *[cc, *result] + end end end -# This method returns the binding of the method that called your -# method. It will raise an Exception when you're not inside a method. -# -# It's used like this: -# def inc_counter(amount = 1) -# Binding.of_caller do |binding| -# # Create a lambda that will increase the variable 'counter' -# # in the caller of this method when called. -# inc = eval("lambda { |arg| counter += arg }", binding) -# # We can refer to amount from inside this block safely. -# inc.call(amount) -# end -# # No other statements can go here. Put them inside the block. -# end -# counter = 0 -# 2.times { inc_counter } -# counter # => 2 -# -# Binding.of_caller must be the last statement in the method. -# This means that you will have to put everything you want to -# do after the call to Binding.of_caller into the block of it. -# This should be no problem however, because Ruby has closures. -# If you don't do this an Exception will be raised. Because of -# the way that Binding.of_caller is implemented it has to be -# done this way. -def Binding.of_caller(&block) #:nodoc: - old_critical = Thread.critical - Thread.critical = true - count = 0 - cc, result, error, extra_data = Continuation.create(nil, nil) - error.call if error +class Binding #:nodoc: + # This method returns the binding of the method that called your + # method. It will raise an Exception when you're not inside a method. + # + # It's used like this: + # def inc_counter(amount = 1) + # Binding.of_caller do |binding| + # # Create a lambda that will increase the variable 'counter' + # # in the caller of this method when called. + # inc = eval("lambda { |arg| counter += arg }", binding) + # # We can refer to amount from inside this block safely. + # inc.call(amount) + # end + # # No other statements can go here. Put them inside the block. + # end + # counter = 0 + # 2.times { inc_counter } + # counter # => 2 + # + # Binding.of_caller must be the last statement in the method. + # This means that you will have to put everything you want to + # do after the call to Binding.of_caller into the block of it. + # This should be no problem however, because Ruby has closures. + # If you don't do this an Exception will be raised. Because of + # the way that Binding.of_caller is implemented it has to be + # done this way. + def of_caller(&block) + old_critical = Thread.critical + Thread.critical = true + count = 0 + cc, result, error, extra_data = Continuation.create(nil, nil) + error.call if error - tracer = lambda do |*args| - type, context, extra_data = args[0], args[4], args - if type == "return" - count += 1 - # First this method and then calling one will return -- - # the trace event of the second event gets the context - # of the method which called the method that called this - # method. - if count == 2 - # It would be nice if we could restore the trace_func - # that was set before we swapped in our own one, but - # this is impossible without overloading set_trace_func - # in current Ruby. + tracer = lambda do |*args| + type, context, extra_data = args[0], args[4], args + if type == "return" + count += 1 + # First this method and then calling one will return -- + # the trace event of the second event gets the context + # of the method which called the method that called this + # method. + if count == 2 + # It would be nice if we could restore the trace_func + # that was set before we swapped in our own one, but + # this is impossible without overloading set_trace_func + # in current Ruby. + set_trace_func(nil) + cc.call(eval("binding", context), nil, extra_data) + end + elsif type == "line" then + nil + elsif type == "c-return" and extra_data[3] == :set_trace_func then + nil + else set_trace_func(nil) - cc.call(eval("binding", context), nil, extra_data) + error_msg = "Binding.of_caller used in non-method context or " + + "trailing statements of method using it aren't in the block." + cc.call(nil, lambda { raise(ArgumentError, error_msg) }, nil) end - elsif type == "line" then - nil - elsif type == "c-return" and extra_data[3] == :set_trace_func then - nil - else - set_trace_func(nil) - error_msg = "Binding.of_caller used in non-method context or " + - "trailing statements of method using it aren't in the block." - cc.call(nil, lambda { raise(ArgumentError, error_msg) }, nil) end - end - unless result - set_trace_func(tracer) - return nil - else - Thread.critical = old_critical - case block.arity - when 1 then yield(result) - else yield(result, extra_data) + unless result + set_trace_func(tracer) + return nil + else + Thread.critical = old_critical + case block.arity + when 1 then yield(result) + else yield(result, extra_data) + end end end -end +end
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