mary

This is a script compiler for Harvest Moon: Friends of Mineral Town and Harvest Moon: More Friends of Mineral Town for the GBA. The end goal is for it to be able to recompile decompiled vanilla scripts into the exact same bytecode.

This is a very rough and minimal version that I wrote over the weekend. I think it works, but I haven't had the chance to test or document much of it yet.

If you are looking for my old attempt at writing this in C++, see StanHash/mary_old.

Usage

mary INPUT > OUTPUT

The input is a file written in a custom script syntax. The output is a fragment of C that defines the data objects for the scripts defined in the source file.

Build

Install Rust development tools if you haven't already. (cargo, rustc, etc.)

cargo build --release

You will find the mary executable into the target/release directory.

Example script

// Script 1 of MFoMT

func 0x106 Func106()
func 0x117 Func117(a)
proc 0x105 Func105(a, b, c)
proc 0x01F Func01F()
proc 0x022 Func022(a)
proc 0x021 Func021()
proc 0x011 Func011(a, b, c)

const CONST_36 = 0x36
const MESSAGE = "\xFF%is \r\nprengant!\x05"

script 1 EventScript_1
{
    var var_0 = Func106()
    var var_1 = CONST_36 + var_0

    if Func117(var_0)
    {
        Func105(0, 1, var_0)
    }
    else
    {
        Func105(0, 2, var_0)
    }

    Func01F()
    Func022(MESSAGE)
    Func021()
    Func011(var_1, 1, 0)
}

Script constructs

// line comment

/*
multiline
comment
*/

Toplevel constructs

func ID NAME(PARAM, ...) // defines a native function.
proc ID NAME(PARAM, ...) // procs are functions that do not return a value.

const NAME = VALUE // defines a constant. Constants must be evaluatable at compile-time

script ID NAME { ... } // defines a script

Script body constructs

// define a constant, same rules as toplevel constants
const NAME = VALUE, ...

// define a variable
var NAME, ...
var NAME = VALUE, ...

// assign to a variable
NAME = VALUE

// call a function or procedure
NAME(ARG, ...)

// conditional. Braces are mandatory
if EXPR { ... }
if EXPR { ... } else { ... }

// for loop. Braces are mandatory
for var i = 0; i < 10; i++ { ... }

// do-while loop. Braces are mandatory
do { ... } while EXPR

// switch statement
switch EXPR
{
    case VALUE { ... }
    ...
    default { ... } // optional
}