4.4.3 The Correctness of this Description In this description of conditions in REXX, I have gone further in the description of how conditions work, their internal data structures, the order in which things are executed etc., than the standard does. I have tried to interpret the set of distinct statements that is the documentation on condition, and design a complete and consistent system describing how such conditions work. I have done this to try to clarify an area of REXX which at first glance is very difficult and sometimes non-intuitive. I hope that the liberties I have taken have helped describe conditions in REXX. I do not feel that the adding of details that I have done in any way change how conditions work, but at least I owe the reader to list which concepts that are genuine REXX, and which have been filled in by me to make the picture more complete. These are not a part of the standard REXX. · REXX does not have anything called a standard condition. There just “are” a set of conditions having different attributes and values. Sometimes there are default values to some of the attributes, but still the are no default condition. · The terms “event” and “incident” are not used. Instead the term “condition” is somewhat overloaded to mean several things, depending on the situation. I have found it advantageous to use different terms for each of these concepts. · Standard REXX does not have condition queue, although a structure of such a kind is needed to handled the queuing of pending conditions when the trap state is DELAY. · The values default-action and delay-action are really non- existing in the Standard REXX documentation. I made them up to make the system more easy to explain. · The two-step process of first raising the flag, and then (possibly at a later stage) triggering the trap, is not really a REXX concept. Originally, REXX seems to allow implementations to select certain places of the interpreter where events are sought for. All standard conditions that can be called by method CALL, can be implemented by checking only at clause boundaries. · Consequently, a REXX implementation can choose to trigger the trap immediately after a condition are raised (since conditions are only raised immediately before the trap would trigger anyway). This is also the common way used in language level 3.50, when only method SIGNAL was implemented. · Unfortunately, the introduction of the state DELAY forces the interpreter to keep a queue of pending conditions, so there is nothing to gain on insisting that raising should happen immediately before triggering. And the picture is even more muddied when the NOTREADY condition is introduced. Since it explicitly allows raising of condition to be done during the clause, even though the triggering of the trap must happen (if method is CALL) at the end of the clause. I really hope that these changes has made the concept of conditions easier to understand, not harder. Please feel free to flame me for any of these which you don’t think is representative for REXX.