Add functions as a first-class type

[python-processing-unit]

Feature proposal

Add support for functions as a first-class type in ASM-Lang. This would allow functions to be assigned to variables, stored in data structures, passed as arguments, and returned from other functions.

Motivation

• Increases language expressiveness and flexibility.
• Enables common functional programming patterns.
• Makes it easier to write concise, readable, and modular code.

Expected behavior

• Functions can be treated as values throughout the ASM-Lang interpreter.
• Syntax and semantics should be clearly documented and tested.
• Example usage and reference changes included in documentation.

[python-processing-unit]

Implemented in commit 1f3fad5.