☜	Metalanguage Description Annotations					☞

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.

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 16-Nov-2023, 17:52:46.

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