Provide SPM ITERATE-like analogue with conditions, similar to LEAVE/DOEXIT

Although this item is a good suggestion, it provides only a minor benefit, and it is far from trivial to implement, test and document. Given internal priorities and resources, we are therefore unlikely to schedule it within the next year or so. We have been informed that according to IBM guidelines this means we should decline this RFE. We are however keeping this item on our internal list of suggested enhancements and may implement it eventually.

From a technical point of view, we are thinking of allowing condition operands to be specified on both LEAVE and ITERATE, following the optional DO label, and it is not at all clear why DOEXIT was implemented separately, with a different syntax.

Jonathan Scott, HLASM and Toolkit

Perhaps DOAGAIN with similar syntax to DOEXIT might be the clearest name to use for this function. It appears reasonably simple to implement, as a conditional form of ITERATE.

However, we are concerned that these macros have already evolved to a level of complexity that is effectively equivalent to a new language, but with syntax that doesn't integrate well with assembler source (especially continuation and indentation), and with closely related functions using different styles. For example, DOEXIT without operands is equivalent to ASMLEAVE but the naming scheme and syntax of these macros is quite different. We are therefore also looking at alternative ways to improve the structured programming capabilities, for example by the use of separate macros for additional conditions, rather than continuing to extend the current scheme, so although we are provisionally accepting this request as a candidate for future implementation, we may still choose to implement a different solution.

Jonathan Scott, HLASM and Toolkit