Description
This command declares a named constant.
Command Syntax
'@x:var' <id> {'~' <exp>}? {':=' <exp>}?
No body is permitted.
The following options are permitted.
| visible | The variable name is declared as visible in the enclosing scope. If visible is specified, then local can not be specified. |
| local | The variable name is declared as local in the enclosing scope. If local is specified, then visible can not be specified. |
Name Semantics
The <id> variable name is declared the scope that surrounds the @x:var command.
Execution Semantics
The variable is initialized to the value of the initial value expression following the :=. If no initial value is specified, then the variable is uninitialized. Attempting to use an uninitialized variable will result in an execution error. The initial value, if specified, and any later value assigned to the variable must satisfy the type or view given following any ~. The result of executing the @x:var command is null.
Examples