_{Official ZPE/YASS documentation}Directives

Directives are written using the @ syntax.

External documentation

Perhaps the most common directives are those associated with external documentation.

External documentation is appended to the functions at compile time when exporting to a library file. This means after the code is compiled, using the -h doc command on the compiled file and requesting the documentation by name will return the text that was allocated to that documentation:

@doc "MyFunction : This function returns true"
@author "Jamie Balfour"
@date "July 2020"
function MyFunction ()
  return true
end function
    

The description must be quoted after the @doc directive. This is available only as of version 1.4.1. Previous versions use a different system.

This kind of documentation can be very useful if you are distributing your compiled code or planning to add it as a library.

Accessing it again is done with the -h ZAC applied on a compiled script.

zpe -h doc -f file.zex -s $function_name

Prior to version 1.4.1

In older versions of ZPE, internal documentation can be exported using @ commands within multiline comments.

/*@doc My function:This function returns true*/
    

The colon in the middle splits the documentation into two halves, one for the name (on the left) and one for the description (on the right).

The standard library (stdLib) contains examples of these directives.

@directive

The @directive is a special compiler directive that tells the YASS compiler to do something. It could be a simple thing such as telling it to do something differently, or it could be to ignore something during compilation.

prevent_auto_include

The prevent_auto_include directive is used to prevent a compiled program having to include a file at the start which can potentially overwrite code within it.

@directive prevent_auto_include : true
    

requires_explicit_declaration

The requires_explicit_declaration directive was added in ZPE 1.12.9 (Piper Pine Marten, September 2024) and tells the compiler to throw an error when it comes across a variable that has been defined previously. To define a variable before use, you can use the string $x = "" syntax and then from there on you may just refer to $x.

@directive requires_explicit_declaration : true

string $x = ""
$x = "Hello world" //This will work
print($x)

$y = "Hello world" //This will not work
print($y)