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Left Hand Pointer

gvn

Annotations

Right Hand Pointer

environment

Introduced in the 1995 ANSI M[UMPS] language standard.

This metalanguage symbol represents the specification of the name of an environment where certain entities may reside. The entities that may reside in other environments than the current processing environment are global variables, routines and LOCKed names.

Examples:

SET X=^|"LONDON"|CUSTOMER(ID,12)
DO GETINFO^|"SANDIEGO"|CUSTUTIL(CUSTOMER,"BALANCE")

gnamind

Introduced in the 1984 ANSI M[UMPS] language standard.

This metalanguage symbol represents a part of an indirect reference to a global variable. In the context of an indirection of the type @name@(subscripts), this metalanguage symbol corresponds to the part between the indirection operators. This entity may be a regular local variable name (see metalanguage symbol rlvn, a regular global variable name (see metalanguage symbol rgvn) or an expritem). In this context, the value between the indirection operator must evaluate to a name of a global variable, possibly with a list of subscripts enclosed in parentheses.

gvn

Introduced in the 1977 ANSI M[UMPS] language standard.

This metalanguage symbol represents a global variable name (possibly with a list of subscripts enclosed in parentheses), including the leading caret (^). An gvn may be either a "straight" global variable name, a naked reference, or an indirected reference to a global variable.

Examples:

^ABC
@("^PQR")
^ABC(1,2,3)
@"^PQR(4,5,6)"
^(4,5)
@"^(6,7)"

Modified in the 1984 ANSI M[UMPS] language standard.

This metalanguage symbol represents a global variable name (possibly with a list of subscripts enclosed in parentheses), including the leading caret (^). An gvn may be either a regular global variable name (see metalanguage symbol rgvn) or an indirected reference to a regular global variable name.

Examples:

^ABC
@("^PQR")
^ABC(1,2,3)
@"^PQR(4,5,6)"
@"^KLM"@(8,9,10)
@"@""^XYZ""@(11,23)"
^(4,5)
@"^(6,7)"

naked indicator

Introduced in the 1977 ANSI M[UMPS] language standard.

The naked indicator is an internal variable in a M[UMPS] system. The value of this variable may be either undefined or defined. When this variable has a defined value, a naked reference will build a reference to a global variable, based on the value of the naked indicator, and the information in the naked reference.

Initially, the naked indicator is undefined.

The naked indicator is defined after each reference to a subscripted global variable and becomes undefined after each reference to an unsubscripted global variable.

A naked reference may redefine the value of the naked indicator.

naked indicator
Before evaluation
Reference Actual reference naked indicator
After evaluation
undefined ^(123) error undefined
undefined ^ABC ^ABC undefined
undefined ^A(1,2) ^A(1,2) ^A(1,
^A(1, ^(123) ^A(1,123) ^A(1,
^A(1, ^(4,5,6) ^A(1,4,5,6) ^A(1,4,5,
^A(1, ^BCD(1) ^BCD(1) ^BCD(
^BCD( ^KLM ^KLM undefined

rgvn

Introduced in the 1984 ANSI M[UMPS] language standard.

This metalanguage symbol represents a regular global variable name. A regular global variable name may look like a name of a global variable (possibly with a list of subscripts enclosed in parentheses); it may look like a naked reference, or it may look like an indirection operator, followed by an expression that evaluates to a name of a global variable (possibly with a list of subscripts enclosed in parentheses), or it may look line an indirection operator followed by an expression that evaluates to a name of a global variable (possibly followed by a list of subscripts enclosed in parentheses, followed by an indirection operator, followed by a list of subscripts enclosed in parentheses.

Modified in the 1995 ANSI M[UMPS] language standard.

A non-naked reference to a global variable may include an environment specification.

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Copyright © Standard Documents; 1977-2018 MUMPS Development Committee;
Copyright © Examples: 1995-2018 Ed de Moel;
Copyright © Annotations: 2003-2008 Jacquard Systems Research
Copyright © Annotations: 2008-2018 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 08-Jan-2016, 18:05:49 .

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