☜	Process-Stack Draft MDC Standard					☞

7.1.2.3 Process-Stack

The PROCESS-STACK is a virtual last-in-first-out (LIFO) list (a simple push-down stack) used to describe the behavior of M[UMPS]. It is used as an aid in describing how M[UMPS] appears to work and does not imply that an implementation is required to use such a stack to achieve the specified behavior. Three types of items, or frames, will be placed on the PROCESS-STACK, Do frames (including Xecutes), extrinsic frames (including exfunc and exvar and asynchronous events) and error frames (for errors that occur during error processing):

1. Do frames contain the execution level and the execution location of the doargument or xargument. In the case of the argumentless Do, the execution level, the execution location of the Do command and a saved value of $Test are saved. The execution location of a process is a descriptor of the location of the command and possible argument currently being executed. This descriptor includes, at minimum, the routinename and the character position following the current command or argument.
2. Extrinsic frames contain saved values of $Test, the execution level, and the execution location.
3. Error frames contain information about error conditions during error processing (see 6.3.2 Error processing).

The term CONTEXT-STRUCTURE is used to refer to a set of information related to the maintenance of the process context.

Copyright © Standard Documents; 1977-2024 MUMPS Development Committee;
Copyright © Examples: 1995-2024 Ed de Moel;
Copyright © Annotations: 2003-2008 Jacquard Systems Research
Copyright © Annotations: 2008-2024 Ed de Moel.

Some specifications are "approved for inclusion in a future standard". Note that the MUMPS Development Committee cannot guarantee that such future standards will indeed be published.

This page most recently updated on 28-Nov-2011, 21:03:45.

For comments, contact Ed de Moel (demoel@jacquardsystems.com)