ZScript named arguments

Note: This feature is for ZScript only.

ZScript supports the ability to add in named arguments. This is useful for leaving other arguments blank in functions and also clearly defining, what argument is for what.

(New from 4.13.0) In addition, with named arguments, the order of the arguments can be changed as desired, as long as all required arguments are provided.

In order to use a named argument, provide its name in the function, followed by : and the value for the argument.

4.13.0 onward

As of GZDoom 4.13.0, named arguments provide extra features:

• Required parameters cannot be skipped, but you can provide their names
• Using named arguments allows passing arguments to functions in any order

For these new features to work, ZScript version must be set to 4.13.0 or later.

version "4.13.0" // as usual, this only needs to be defined once in the root zscript file

// elsewhere in the code:

// Skips xofs, yofs, yvel, and angle parameters. Arguments are
// provided in arbitrary order, with flags being defined
// before offsets and velocity:
A_SpawnItemEx(missile: 'Rocket', flags: SXF_NOCHECKPOSITION|SXF_TRANSFERPITCH|SXF_SETTARGET, zofs: 32, xvel: cos(pitch) * 20, zvel: -sin(pitch) * 20);

Pre-4.13.0

In earlier versions of ZScript certain restrictions are present:

• Required parameters cannot be skipped, and their names cannot be used.
• All arguments must be provided in the same order as they're defined in the function

// Skips xofs, yofs, yvel, and angle parameters. These are also in chronological order:
A_SpawnItemEx('Rocket', zofs: 32, xvel: cos(pitch) * 20, zvel: -sin(pitch) * 20, flags: SXF_NOCHECKPOSITION|SXF_TRANSFERPITCH|SXF_SETTARGET);