☜ | Extrinsic Variable exvar1990 Version of ANSI Standard | ☞ |
exvar | ::= | $ $ labelref |
See 2.5.7 for the definition of labelref.
Extrinsic special variables are denoted by the prefix $$ followed by a labelref. Extrinsic special variables invoke a MUMPS subroutine to return a value. When an extrinsic special variable is executed, the current value of $T, the current execution level, and the current execution location are saved in an exvar frame on the PROCESS-STACK.
Execution continues at the first command of the formalline specified by the labelref. Execution of an exvar to a levelline is erroneous.
Upon return from the subroutine the value of $T and the execution level is restored, and the value of the argument of the Quit command that terminated the subroutine is returned as the value of the exvar.
An extrinsic special variable whose labelref is x is identical to the extrinsic function:
$$x()
Note that label x must have a (possibly empty) formallist.
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Copyright © Examples: 1995-2024 Ed de Moel;
Copyright © Annotations: 2003-2008 Jacquard Systems Research
Copyright © Annotations: 2008-2024 Ed de Moel.
This page most recently updated on 13-Sep-2014, 12:57:29.
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