The ALIAS Statement

IMLPlus provides the ALIAS statement to allow you to create aliases for modules. An alias is an alternative name for a module. An alias is similar to a function pointer in the C programming language. You can create aliases for the following types of modules:

• User-defined modules
• The IMLPlus modules described in Overview of IMLPlus Module Reference
• The IMLMLIB modules

You cannot create aliases for IML's built-in functions and subroutines.

The syntax of the ALIAS statement is

alias <*>name( parameters ) expression;

where

• The optional * indicates that the module is a function as opposed to a subroutine.
• name is the name of the alias.
• parameters is the declarations of the parameters required by the module.
• expression is an expression that evaluates to the name of the module to which the alias refers.

Some examples of using the ALIAS statement are:

alias *Evaluate( x ) "MyFunction";

alias DoAction( int n ) "MySubroutine";

m = "MyFunction";
alias *Evaluate( x ) m;

declare String s = "MySubroutine";
alias DoAction( int n ) s;

After you create an alias for a module, you can use the alias anywhere you would normally use the module's real name. For example:

y = Evaluate( 3.14 );
run DoAction( 2 );

An alias that is defined outside all modules has global scope and is in effect for the remainder of the program. An alias that is defined inside a module has local scope and is in effect only inside the module.

You can redefine an alias so it refers to a different module as long as all the modules referred to by the alias have the same signature (i.e. parameter list and return type).