# Io Reference

Core / Core / Block

|  | Blocks are anonymous functions (messages with their own locals object). They are typically used to represent object methods.
|  | Formatter Helper object for the `asString` method. argumentNames Returns a List of strings containing the argument names of the receiver. asSimpleString Returns a short description of the receiver. asString Returns a full description of the receiver with decompiled code. call(arg0, arg1, ...) Activates the receiver with the provided arguments. code Returns a string containing the decompiled code of the receiver. justSerialized(stream) Writes the receiver's code into the stream. message Returns the root message of the receiver. passStops Returns whether or not the receiver passes return/continue/break to caller. performOn(anObject, optionalLocals, optionalMessage, optionalSlotContext) Activates the receiver in the target context of anObject. Returns the result. print prints an Io source code representation of the block/method println Same as `print`. profilerTime Returns clock() time spent in compiler in seconds. scope Returns the scope used when the block is activated or Nil if the target of the message is the scope. setArgumentNames(aListOfStrings) Sets the receiver's argument names to those specified in aListOfStrings. Returns self. setCode(aString) Set's the receiver's message to a compiled version of aString. Returns self setMessage(aMessage) Sets the root message of the receiver to aMessage. setPassStops(aBool) Sets whether the receiver passes return/continue/break to caller. setProfilerOn(aBool) If aBool is true, the global block profiler is enabled, if false it is disabled. Returns self. setScope(anObjectOrNil) If argument is an object, when the block is activated, it will set the proto and self slots of its locals to the specified object. If Nil, it will set them to the target of the message.