Macro Support

[yael333]

Macro Support

Description

This pull request adds support for macros in the xx file format. Macros allow users to define reusable chunks of code and replace them with their expanded versions in a preprocessed way. While the implementation is complete to my daily use - there might be design choices that don't align with the project. Please change as see fit if at all ~!

┌─ Macros ───────────────────────────────────────────────────────────
│ xx now supports preprocessed macros~
│ They're in Lisp-esque syntax and have a certain pattern:
| (MACRO ARG1 ARG2 ... )
│ There's one single predefined macro and it is $DEF NAME BODY,
| it defines a macro and is our only interface with the macro system.
└───────────────────────────┐
( $DEF COM "4D 45 4F 57" )  | <-- Here we define macro magic COM
( $DEF SMB "FF534D42" )     |     Macros expand to xx syntax
( $DEF MBR "55 AA")         |     Ä<       Hail Lisp          >Ä
┌───────────────────────────┘
│ Let's invoke some macros!
└────────────────────────────────┐
(COM)  ; Expands to MEOW         |
                                 |
┌─ Macro Functions ──────────────┘
│ Defining simple macros is nice but there's much more to it.
│ You can define macro functions that operate on data,
| Code starts with py followed by minified python function <3
└─────────────────────────────────────────────────────-──────────────
( $DEF $INC py'λ x : int(x,) + 1' ) -- Macros need to return a function, easiest way is to define a lambda function.
                                    -- All parameters are text - cast type as you wish
                                    -- In order to simplify the syntax both \. and λ expand to lambda :D
( $INC 19 )  --> 20
( $INC 48 )  --> 111

Changes Made

• Added a new xxMacroProcessor class to handle macro processing (almost entirely self contained).
• Based on a CLI parameter (off by default) it processes macros on a document - happens before the tokenization of a file.
• Updated the example/macro.xx file to demonstrate the usage of macros.

Testing

I have tested the macro functionality with various xx files, including the provided example, to ensure proper expansion and compilation. Although some of the design choices provide some quirks showcased in the example, they're documented and not invoked by default