☜	OMI and MUMPS 1995 Version of ANSI (Equivalent to Current ISO Version) of Standard					☞

4 General description
4.1 OMI and MUMPS

ANSI/MDC X11.1 defines the components of the MUMPS database and operations on them. OMI makes some of these operations, listed here, available over a network. The following references are to the formal definitions in ANSI/MDC X11.1; the additional text is for information only:

• environment: 7.1.2.4 identifies a specific set of all possible names – a name space. A particular name may appear only once in an environment. Typical implementations place an environment in a directory or a user class, and – with a network – on a node as well.
• gvn: 7.1.2.4 Global variables are persistent data records organized into trees. gvn is the name of a global variable, for example:
     ^INV(5321,"Denver","qu")
  A global variable may optionally have a value, and it may optionally have descendants. A tree of global variables is informally called a "global."
• naked reference: 7.1.2.4 a shorthand form of gvn referring to the last-used gvn.
• nref: 8.2.12 The objects of database lock operations are organized into trees. Their names are similar to gvns, but they relate to gvns only by an application’s convention. nrefs have no values.
• $Data: 7.1.5.3 Function of a gvn indicates whether the variable it names has a value and whether it has descendants.
• $Get: 7.1.5.7 Function of a gvn returns the value of the variable it names, or the empty string if the variable is not defined.
• $Job: 7.1.4.10 An unsigned decimal integer uniquely identifies a process on a particular computer.
• Kill: 8.2.11 deletes a global variable and its descendants.
• Lock+: 8.2.12 claims exclusive use of an nref or a list of nrefs. If the claim succeeds, other concurrent processes’ claims on those nrefs will not succeed.
• Lock-: 8.2.12 releases a claim on an nref or a list of nrefs.
• Merge: 8.2.13 assigns the value of one variable to another and then assigns the values of all the first variable’s descendants to corresponding descendants of the second variable.
• $Order: 7.1.5.11 Function of a gvn returns the final subscript of the next gvn in a defined tree-walking order.
• $Query: 7.1.5.15 Function of a gvn returns the next gvn in a defined tree-walking order.
• Set: 8.2.18 creates a global variable and assigns it a value.
• Set $Extract: 8.2.18 creates a global variable and modifies its value by assigning a range of its character positions.
• Set $Piece: 8.2.18 creates a global variable and modifies its value by assigning one or more of its pieces.

B.6 (of this International Standard, not X11.1) suggests how implementations may combine these basic operations to achieve more complex MUMPS operations.

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.

This page most recently updated on 16-Nov-2023, 16:56:40.

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