Metalanguage, letter A

actual, actualkeyword, actuallist, actualname, algoref, alpha, alphanum, alternation, applicationattribute, argument assignargument, assigndestination, assignleft


actual

Introduced in the 1990 ANSI M[UMPS] language standard.

This metalanguage symbol represents a parameter in an "actual" parameter list (formal parameter list: at the label of the invoked subroutine or function; actual parameter list: in the call to that subroutine or function).

An actual parameter is either an expression (passed by value) or a name of a local variable, preceded by a dot (passed by reference).


actualkeyword

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

This metalanguage symbol represents a keyword in a parameter of a method of an object. Such a keyword can be either a name or a string literal.


actuallist

Introduced in the 1990 ANSI M[UMPS] language standard.

This metalanguage symbol represents an actual parameter list (formal parameter list: at the label of the invoked subroutine or function; actual parameter list: in the call to that subroutine or function).

An actual parameter list starts with a parenthesis open, then follows a list of actual parameters, separated by commas, and ends with a parenthesis close.


actualname

Introduced in the 1990 ANSI M[UMPS] language standard.

This metalanguage symbol represents the name of a parameter that is passed by reference.


algoref

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

This metalanguage symbol represents the algoritm that will be executed to obtain a certain result. An algorithm is typically a reference to an extrinsic function (potentially using the external calling syntax), occasionally an intrinsic function would be used. In cases where an algorithm specification is required, but no algorithm is currently available, the empty string may be specified instead of the algorithm specification.


alpha

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

This metalanguage symbol represents any of the 52 upper and lower case alphabetic characters in the ASCII set.

Removed in the 1995 ANSI M[UMPS] language standard (see the meta-language symbol ident).


alphanum

Introduced in the 1995 ANSI M[UMPS] Windowing Application Programmer's Interface standard.

This metalanguage symbol represents either an alphabetic character or a digit.


alternation

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

This metalanguage symbol represents a specification of multiple alternate patterns that may occur to satisfy part of a pattern match specification.

A list of alternate patterns looks like a list of pattern atoms (separated by commas) enclosed in parentheses.

Modification in a future ANSI M[UMPS] language standard.

A list of alternate patterns looks like a list of pattern specifications (separated by commas) enclosed in parentheses.

Note: The limitation to pattern atoms in the 1995 ANSI M[UMPS] language standard was unintended.


applicationattribute

Introduced in the 1995 ANSI M[UMPS] Windowing Application Programmer's Interface standard.

This metalanguage symbol represents an application specific attribute for a window characteristic specification. Its value must be valid for usage as a subscript, and its first letter must be an uppercase "Y".


argument

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

This metalanguage symbol represents an argument of a M[UMPS] command. An argument follows either the syntax of a specific command's argument (see closeargument, doargument, etcetera), or starts with an indirection operator (@) followed by an expression that evaluates to a list (separated by commas) of such specific arguments.


assignargument

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

This metalanguage symbol represents an occurrence of an argument of the ASSIGN command. Examples of valid arguments for the ASSIGN command appear in an earlier section. The argument of the ASSIGN command is either a destination as described below, followed by an equal sign (=), followed by an expression, or an indirection operator (@) followed by an expression that evaluates to a list (separated by commas) of such arguments.

The destination can be either a local variable (possibly subscripted), or a property of an object, or a list of such entities (separated by commas; enclosed in parentheses).


assigndestination

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

This metalanguage symbol represents the target of an argument of the ASSIGN command. Such a target may be either a single local variable or property of an object, or a list (enclosed in parentheses; separated by commas) of destinations.


assignleft

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

This metalanguage symbol represents an entity that may appear on the left-hand side of the equal sign in an argument of the ASSIGN command. Such an entity may be either a local variable or a property of an object.


This document is © Ed de Moel, 1995-2005.
It is part of a book by Ed de Moel that is published under the title "M[UMPS] by Example" (ISBN 0-918118-42-5).
Printed copies of the book are no longer available.

This document describes the various metalanguage terms starting with the letter "A" that are used throughout the M[UMPS] standards, as well as some other terms that may not be obvious to all readers of the M[UMPS] language standards.

The information in this document is NOT authoritative and subject to be modified at any moment.
Please consult the appropriate (draft) language standard for an authoritative definition.

In this document, information is included that will appear in future standards.
The MDC cannot guarantee that these 'next' standards will indeed appear.