Difference between revisions of "Category:LSL User-Defined Functions"

User-Defined Functions

This category contains custom pre-defined function contributions from the LSL community to extend the abilities of LSL. To add a wiki page to this category, include a link to this page. You may use the Template:LSL_Function (with "mode" set to user) to create the page to be added here.

Go to the Functions page to view the built-in functions.

About User-Defined Functions

LSL allows user-defined functions which will help keep scripts compact and readable, and allow code reuse. The LSL Style Guide suggests that user-defined functions should be placed before the default state definition and after user-defined variables.

The definitions are as follows:

<return_type> function_name([<parameter1_type> parameter1[, <parameter2_type> parameter2[, ...]]])
{
  function_statements;

  ...

  return value_of_return_type;
}

• User-defined functions must be defined before any states in the script or a syntax error will be generated on compilation.
• return_type and parameterN_type may be any LSL variable type.
  • The return_type may also be omitted for a void type function. Such a function is not required to use the return statement at all, and if one is used it will have no parameter.
• There are no known limits on the maximum number and size of parameters, beyond normal script memory limits.
  • If the function requires no parameters, the entire parameter list can be omitted.
• Parameters are passed by value, as with built-in functions. They behave like local variables and writing into them has no effect on what the function was called with.
  • Entering a user-defined function starts a new scope. Only global variables and the function parameters are visible; any local variables from where the function was called from are not directly available.
• If multiple return values are desired, they can be packed into a list, a vector or a rotation, depending on what you need to return.

Examples

// example with void return type:

let_prim_say_something_and_include_owner_info(string message)
{
    key ownerKey = llGetOwner();
    string ownerName = llKey2Name(ownerKey);

    llSay(PUBLIC_CHANNEL, "/me (owned by " + ownerName + "): " + message);
}

default
{
    state_entry()
    {
        let_prim_say_something_and_include_owner_info("Hello world!");
    }
}

// example with integer return type (actually it's a boolean)

integer is_sun_up()
{
    vector sunDirection = llGetSunDirection();

    if (sunDirection.z < 0.0)
        return FALSE;

    // else
        return TRUE;
}

default
{
    state_entry()
    {
        if (is_sun_up())
            llSay(PUBLIC_CHANNEL, "Good day!");
        else
            llSay(PUBLIC_CHANNEL, "Good night!");
    }
}

Below is a list of functions on this wiki that have been included in this category: