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FUNCTIONS
A function is a way of grouping together some lines of code. A Telix
script consists of one or more functions. There are quite a few
advantages to having functions:
One function can be called from another, to do a certain task.
The calling function does not have to know anything about the
called function other than what it does. This allows a script
to be split up into modular units, and makes code writing and
debugging easier.
As mentioned above, what a function does it private. This means
that data variables defined in a function are local to that
function, and therefore you do not have to worry about another
part of the script unintentionally modifying them.
A library of functions can thus be built. Later, you do not
have to re-write old code.
Functions are defined in the following format:
<funcname>(<arg1>, <arg2>, ..., <argN>)
{
<variable_def>
...
<variable_def>
<statement>
...
<statement>
}
<funcname> is the name of the function. It follows the same rules of
other identifiers in SALT. There can only be one function that uses
a given name, however.
<arg1> through <argN> are the declarations of the arguments
(parameters) that have been passed to the function by its caller
(sometimes, to accomplish its task, a function needs to have some
values passed to it). Each argument is defined in the form <type>
<name> where <type> is 'int' or 'str', and <name> is the name it
should be called by. At present, a function is not allowed to have
more than 12 values passed to it.
<variable_def> is a variable definition, as described in the above
section on that topic. Any number of variables may be declared at
this part of the function. All such variables will be local vari-
ables and available only to this function.
<statement> is an actual line of code. There may be as many lines of
statements in the function as needed. The format of a statement is
described below. First though, here is an example of a complete
function:
max ( int a, int b )
{
int result;
if (a > b)
result = a;
else
result = b;
return result;
}
This function returns the larger (maximum) of the two values passed
to it. It could have been written much more simply (without the use
of the variable), but was written this way so that all the function
elements would be there.
See Also:
structure
statements
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