GTL Operators

GTL supports standard arithmetic operators along with some advanced template operators.

The following standard arithmetical and logical operators are supported, where x and y can be numbers or templates resolving to numbers:

Operator	Description
`%+(x,y)%`	Addition operator
`%-(x,y)%`	Subtraction operator
`%*(x,y)%`	Multiplication operator
`%/(x,y)%`	Division operator
`%&(x,y)%`	Logical bitfield `and` operator

In this example, the template in the left column produces the output on the right:

Template	Results
Base number= %Number% Number+1= %+(Number,1)% Number-1= %-(Number,1)% Number2= %(Number,2)% Number/2= %/(Number,2)% Number&1= %&(Number,1)%	Base number= 4 Number+1= 5 Number-1= 3 Number*2= 8 Number/2= 2 Number&1= 0

Template

Results

Base number=   %Number%       
Number+1=      %+(Number,1)% 
Number-1=      %-(Number,1)% 
Number*2=      %*(Number,2)% 
Number/2=      %/(Number,2)% 
Number&1=      %&(Number,1)%

Base number=   4       
Number+1=      5 
Number-1=      3 
Number*2=      8 
Number/2=      2 
Number&1=      0

The following advanced template operators are also supported:

Operator	Description
*	Dereferencing operator - The syntax []+`local-value` [(`param-list`)] returns the object member defined by the evaluation of []+ `local-value`. If the given object member happens to be a template, a parameter list may be specified. Applying the star operator corresponds to a double evaluation (the * operator acts as a dereferencing operator). If a local variable is defined as: `.set_value(C, Code)`, then `%C%` will return "Code" and `%C%` will return the result of the evaluation of %Code%. In other words, `%C%` can be thought of as `%(%C%)%` (the latter syntax being invalid).
!	Power evaluation operator - Evaluates the results of the evaluation of the variable as a template. For example, you define a comment containing a variable like `%Code%.` When you use the ! operator in `%!Comment%`, the actual value of %Code% is substituted for the variable block. Without the ! operator, the variable remains unevaluated. The ! operator may be applied any number of times. For example: %!!template% This outputs the results of the evaluation of the evaluation of the evaluation of template 'template'
?	The ? operator is used to test the existence of a template, a local variable, a volatile or an extended attribute. It returns "true" if the variable exists, "false" otherwise. For example, if custname is defined whereas custid is not, then the template: .set_value(foo, tt) %custname?% %custid?% outputs: true false
+	The + operator is used to test if an object property is visible in the interface. For example, you could test if the Type box is displayed in the General tab of a database property sheet in a DMM, and thus that a Replication Server XEM is attached to the model. The %Database.Type+% template will output false if no XEM is attached to the model.