Button for 1977 Button for 1984 Button for 1990 Button for 1995 Button for MDC Button for notes Button for examples
Left Hand Pointer

Metalanguage Description

Annotations

Right Hand Pointer

CB

Approved for inclusion in a future M[UMPS] language standard.

This metalanguage symbol represents the special character "Right bracket" or "Close Bracket" ("]"). This metalanguage element is used to avoid confusion between the metalanguage symbol that implies an optional element with the actual character.

CR

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

This metalanguage symbol represents the special character "Carriage Return". Since this character is normally not visible in printed text, the representation CR is used in the ANSI M[UMPS] language standard to indicate that this special character is present in a specific location.

Starting from the 1990 ANSI M[UMPS] language standard, this symbol is spelled as CR (underscored).

FF

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

This metalanguage symbol represents the special character "Form Feed". Since this character is normally not visible in printed text, the representation FF is used in the ANSI M[UMPS] language standard to indicate that this special character is present in a specific location.

Starting from the 1990 ANSI M[UMPS] language standard, this symbol is spelled as FF (underscored).

L

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

This metalanguage symbol indicates that an indefinite repetition of a certain entity may occur. E.g. L name means: a list of names (separated by commas), and is equivalent with name [ , name ] ...

LF

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

This metalanguage symbol represents the special character "Line Feed". Since this character is normally not visible in printed text, the representation LF is used in the ANSI M[UMPS] language standard to indicate that this special character is present in a specific location.

Starting from the 1990 ANSI M[UMPS] language standard, this symbol is spelled as LF (underscored).

OB

Approved for inclusion in a future M[UMPS] language standard.

This metalanguage symbol represents the special character "Left bracket" or "Open Bracket" ("["). This metalanguage element is used to avoid confusion between the metalanguage symbol that implies an optional element with the actual character.

SP

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

This metalanguage symbol represents the special character "Space". Since this character is normally not visible in printed text, the representation SP is used in the ANSI M[UMPS] language standard to indicate that this special character is present in a specific location.

Starting from the 1990 ANSI M[UMPS] language standard, this symbol is spelled as SP (underscored).

V

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

This metalanguage symbol represents a constraint. Typically, this symbol occurs following a general symbol (e.g. expr), and is followed by a more specific symbol. The sequence "general" V "specific" is to be read as: take the "general" thing, but limit its options to those of the "specific" thing.

E.g.:expr V "CHARACTER" means "an expression that evaluates to the string value "CHARACTER"". (Sounds like: choose any color, as long as it is black, doesn"t it...)

The V metalanguage element comes into play in those sections of the language where "indirection" is used. For instance, a typical description of the syntax of one specific form of the SET command might look like:
      SET SP lvn = expr
And, if indirection is used, that could turn into:
      SET SP @ expr V lvn = expr
Which would mean that, on the left-hand side of the = operator, there would be an expression, but that expression should be constrained in the sense that its value must correspond to the syntax of a local variable name.

In other words, the code snippets
      SET abc=def+ghi
      SET @"abc"=def+ghi
Would both have the same meaning as MUMPS code.
However, the snippet
      SET @"123"=def+ghi
Would pass the parsing at its first level (it matches SET SP @ expr = expr), but it would fail at the next level when the constraint "123" V lvn is exercised.

VB

Approved for inclusion in a future M[UMPS] language standard.

This metalanguage symbol represents the special character "Vertical bar" ("|"). This metalanguage element is used to avoid confusion between the metalanguage symbol that implies an choice list with the actual character.

Button for 1977 Button for 1984 Button for 1990 Button for 1995 Button for MDC Button for notes Button for examples

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 12-Sep-2014, 10:04:33 .

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