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-rw-r--r--railties/lib/binding_of_caller.rb168
1 files changed, 83 insertions, 85 deletions
diff --git a/railties/lib/binding_of_caller.rb b/railties/lib/binding_of_caller.rb
index 759e760016..d18fbdef3d 100644
--- a/railties/lib/binding_of_caller.rb
+++ b/railties/lib/binding_of_caller.rb
@@ -1,85 +1,83 @@
-begin
- require 'simplecc'
-rescue LoadError
- class Continuation #:nodoc:
- def self.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
-
-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 self.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.
- 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)
- 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)
- end
- end
- end
-end \ No newline at end of file
+begin
+ require 'simplecc'
+rescue LoadError
+ class Continuation; end # :nodoc: # for RDoc
+ 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]
+ end
+end
+
+class Binding; end # for RDoc
+# 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)
+ 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.
+ 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)
+ 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)
+ end
+ end
+end