Metalanguage, letter D

dattribute, dechar, Defining occurrence, Descendant, device, deviceattribute, devicecommand, devicekeyword, deviceparam, deviceparameters, devicexpr, devn, digit, display, displaycolor, dkeyword, dlabel, dmode, doargument, drawarc, drawbcolor, drawbitmap, drawbox, drawcommand, drawfface, drawfillpattern, drawfsize, drawfstyle, drawline, drawmode, drawnum, drawoval, drawpencolor, drawpensize, drawpicture, drawpie, drawpoint, drawtext, drawtype, drawunits


dattribute

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

This metalanguage symbol represents a display attribute. Such an attribute is identified by an expression that evaluates to one of "BCOLOR", "CLIPBOARD", "COLOR", "COLORTYPE", "FCOLOR", "FOCUS", "KEYBOARD", "PEN", "PLATFORM", "PRESOURCE", "PTR", "SIZE", "SPECTRUM", "TYPEFACE", "UNITS", or to an implementation-specific value (starts with "Z"), or to an application-specific value (starts with "Y").

To be modified in a future ANSI M[UMPS] Windowing Application Programmer's Interface.

The values "FFACE", "FSIZE", "FSTYLE", "PTYPE", "TBCOLOR" and "TFCOLOR" are added to the list of possible attribute codes.


dechar

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

This metalanguage symbol represents the value of one of the directives of the FORMAT library function. The value represented by this metalanguage symbol is the "decimal separator character", a single character that is used to separate the integer parts from the decimal fractions in numbers.


Defining occurrence

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

The defining occurrence of a label is the occurrence in a routine where the label is specified (left of the line start white space). In any routine, any specific label may occur at most once in a defining occurrence.

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

The error code for multiple defining occurrences of the same label is M57.


Descendant

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

A variable has a name and optionally subscripts.

When two variables have the same name, and one has more subscripts than the other, while all subscipts that the one with lesser subscripts has occur in the other variable with the same variable, then the variable with more subscripts is called a descendant of the variable with less subscripts.

For example, assume that the following elements of Y are defined:

Y(0)=0
Y(1)=1
Y(1,2)=2
Y(1,2,3)=123

Then Y(1,2,3) is a descendant of Y, of Y(1) and of Y(1,2), but not of Y(0) and Y(1,2) is a descendant of Y and Y(1).


device

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

This metalanguage symbol represents an implementation-specific device identifier.


deviceattribute

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

This metalanguage symbol represents a keyword that identifies a device parameter to which a value can be assigned. A device keyword looks like a name.

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

A device keyword may also be preceded with a slash.


devicecommand

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

This metalanguage symbol represents a command that may be executed in the context of a controlmnemonic. Possible commands in this context are OPEN, USE and CLOSE.


devicekeyword

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

This metalanguage symbol represents a keyword that identifies a device parameter. A device keyword looks like a name.

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

A device keyword may also be preceded with a slash.


deviceparam

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

This metalanguage symbol represents a device parameter. A device parameter looks like an expression, a keyword, or a sequence of a keyword, equal sign (=) and an expression that signifies the value to be attached to the keyword in question.


deviceparameters

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

This metalanguage symbol represents any implementation-specific parameters to be observed for a certain device or file. A specification of such parameters may be either a single expression, or a list of expressions (separated by colons), enclosed in parentheses.

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

Instead of the just the simple expressions, there may be device parameters. If a device parameter is a simple expression, its meaning is still implementation-specific. If a device parameter is a keyword or a keyword=value combination, its meaning is standardized and portable.


devicexpr

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

This metalanguage symbol represents an expression that evaluates to an implementation-specific identification for a device.


devn

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

This metalanguage symbol represents an expression that evaluates to the name of a device. Such an expression may be preceded by a specification of the environment where the device is known. Names of environments are enclosed in vertical bars.


digit

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

This metalanguage symbol represents any of the 10 numeric characters (0 through 9).


display

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

This metalanguage symbol represents the identification of a device that is used for the presentation of windows. (It is the metalanguage name for the piece of hardware that is called a "display" or "monitor".) This metalanguage symbol occurs as an expression that is only limited in that its value must be valid to be used as a subscript. This value is typically used as the first subscript of ^$DISPLAY.


displaycolor

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

This metalanguage symbol represents a specification of the capability of a display to show colours or shades of grey. This metalanguage symbol occurs as an expression that evaluates to either one of the values "COLOR", "GREY" or "MONO", or is an implementation-specific value (starts with "Z").


dkeyword

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

This metalanguage symbol represents an expression that evaluates to the value "DRAW".


dlabel

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

This metalanguage symbol represents a specification of a label, either "directly" or "indirectly".


dmode

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

This metalanguage symbol represents a code for the effect on existing pixels in the drawing area that is caused by any additional drawing activity. This metalanguage symbol occurs as an expression that evaluates to either "SOLID" or "XOR", or to an implementation-specific value (starts with "Z").


doargument

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

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

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

The argument of the DO command is either a destination, optionally followed by a parameter list, or an indirection operator (@) followed by an expression that evaluates to a list (separated by commas) of such arguments.

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

The destination of a DO command may also be an external subroutine.

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

The argument of the DO command may also be a method of an object.

DO word.Insert("Hello World.")
executes the method Insert of the object that is accessible through the value of local variable word.


drawarc

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

This metalanguage symbol represents an expression that evaluates to the value "ARC".


drawbcolor

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

This metalanguage symbol represents an expression that evaluates to the value "BCOLOR".


drawbitmap

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

This metalanguage symbol represents an expression that evaluates to the value "BITMAP".


drawbox

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

This metalanguage symbol represents an expression that evaluates to the value "BOX".


drawcommand

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

This metalanguage symbol represents a command to be executed in a window that involves some drawing activity. This metalanguage symbol occurs as an expression that evaluates to one of "ARC", "BCOLOR", "BITMAP", "BOX", "DMODE", "DRAWTEXT", "FCOLOR", "FFACE", "FILLPAT", "FSIZE", "FSTYLE", "LINE", "OVAL", "PENSIZE", "PICTURE", "PIE" or "POINT", or to an implementation-specific value (starts with "Z").


drawfface

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

This metalanguage symbol represents an expression that evaluates to the value "FFACE".


drawfillpattern

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

This metalanguage symbol represents an expression that evaluates to the value "FILLPAT".


drawfsize

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

This metalanguage symbol represents an expression that evaluates to the value "FSIZE".


drawfstyle

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

This metalanguage symbol represents an expression that evaluates to the value "FSTYLE".


drawline

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

This metalanguage symbol represents an expression that evaluates to the value "LINE".


drawmode

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

This metalanguage symbol represents an expression that evaluates to the value "DMODE".


drawnum

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

This metalanguage symbol represents a numeric expression that indicates the sequence in which certain drawing commands are executed.

The commands in ^$WINDOW(window,"G",gadget,"DRAW",seq) are executed in numerical order of the final subscript (seq). The value of this final subscript is represented by drawnum.

For portability, the number of drawing commands in this context should not exceed 2,047.


drawoval

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

This metalanguage symbol represents an expression that evaluates to the value "OVAL".


drawpencolor

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

This metalanguage symbol represents an expression that evaluates to the value "FCOLOR".


drawpensize

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

This metalanguage symbol represents an expression that evaluates to the value "PENSIZE".


drawpicture

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

This metalanguage symbol represents an expression that evaluates to the value "PICTURE".


drawpie

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

This metalanguage symbol represents an expression that evaluates to the value "PIE".


drawpoint

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

This metalanguage symbol represents an expression that evaluates to the value "POINT".


drawtext

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

This metalanguage symbol represents an expression that evaluates to the value "DRAWTEXT".


drawtype

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

This metalanguage symbol represents a code for the type of drawing commands that can be specified. This metalanguage symbol occurs as an expression that evaluates to either the value "MDRAW" or to an implementation-specific value (starts with "Z").


drawunits

Approved for inclusion in a future ANSI M[UMPS] Windowing Application Programmer's Interface standard.

This metalanguage symbol represents an expression that evaluates to the value "UNITS".


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 "D" 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.