Pinnacle Speakers DEKO500 User Manual

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For example, an array named 

$table

 might include these elements:

$table[3]

$table[42]

$table[$count+1]

$table[9999]

Deko500 allocates array elements as needed. The subscripted variables in the above
example will occupy only four variable slots, not ten thousand.

By default, most variables are local variables. A local variable is allocated
temporarily during macro playback, then deleted automatically when the macro stops.
One macro cannot reference a second macro’s local variables, even if the second
macro is a subroutine of the first.

Global variables must be declared with the 

global

 command, and can be shared

among multiple macros. Once declared, a global variable remains until you either
delete it by using the 

free

 command, or exit Deko500.

Deko500 has a set of built-in global variables, known as system variables, which
provide information about the state of your system. System variables are preceded by
the at-sign symbol (

@

), and are often referred to as at-sign variables.

Some system variables are read-only; you cannot change their values. Examples of
read-only system variables are 

@lines

 and 

@dots

, which describe the current video

standard, and the pre-defined colors 

@red

, 

@blue

 and 

@green

.

Other system variables may be assigned values. For example, the system variable

@wordwrap

can be set to 0 to disable word wrap, or 1 to enable it

In the previous topic, you saw that variable assignment is indicated by the equal sign
(=), which is just one of many symbols, known as operators, that represent operations
performed on data.

The Deko500 Macro Programming Language uses a subset of the operators available
in C, as well as a few additions specific to Deko500.

Arithmetic operators perform mathematical operations within expressions:

+

$a + $b

adds $a and $b

-

$a - $b

subtracts $b from $a

*

$a * $b

multiplies $a by $b

/

$a / $b

divides $a by $b

%

$a % $b

calculates remainder of $a/$b

-

-$a

negates the value of $a

You can perform arithmetic operations on one-character strings by adding or
subtracting integer values to the character. For example, the expression 

"A"+1

 has

the value 

"B"

.

Using single quotation marks in an expression yields the numerical value of the
character key. For example, 

’A’+1

 has the value 

66

.