`fun` statement

The fun keyword is used to define & undefine reference::typeql/functions/index.adoc.

A function can be defined as follows:

define
fun <name>(<arguments>) -> <return>:
<body>
<return-statement>

A function can be undefined using:

undefine fun <name>;

A function’s signature and implementation can be re-defined as follows:

redefine
fun <name>(<arguments>) -> <return>:
<body>
<return-statement>

fun statement