Scythe is a programming language that compiles to REAPER's JSFX, the language used for writing audio effects and instruments that you can instantly hear and tweak in real time.

Scythe makes it easier to read and write code, especially for more complicated projects.
It adds many features to JSFX, including:

• C-like syntax
• Structs
• Block scope
• A simple type system, including integer, boolean, pointer, array, and struct types
• Better control flow, including return, break, and continue statements
• For loops
• Enforcing variable declaration before use
• Nested functions

Scythe provides access to all built-in JSFX functions, meaning it has full GFX support. It can also be used with libraries written in JSFX.

Here is a list of features that aren't supported (yet)

• Drop down sliders
• Named #strings
• Global memory (gmem[], global.*)
• JSFX preprocessor

An audio buffer with adjustable play speed, written in Scythe:

input speed [default: 1, min: -2, max: 2];

struct Sample
{
	float l;
	float r;
}

Sample* buffer;
float write;
float read;

@sample
{
	buffer[write] = Sample {
		.l = jsfx.spl0,
		.r = jsfx.spl1,
	};
	++write;

	jsfx.spl0 = buffer[read].l;
	jsfx.spl1 = buffer[read].r;
	read += speed.value;
}

Compiled JSFX output:

desc:readme example
slider1:speed=1<-2,2,0>speed

@init
buffer = 0;
write = 0;
read = 0;

@sample
buffer[(0 | write) * 2 + 0] = spl0;
buffer[(0 | write) * 2 + 1] = spl1;
write += 1;
spl0 = buffer[(0 | read) * 2 + 0];
spl1 = buffer[(0 | read) * 2 + 1];
read += speed;

REAPER is needed to run JSFX effects.

First, download the executable or compile it yourself.

To compile to a JSFX plugin, open a terminal in the executable's directory and run

scythe <source_file> [output_file]

where

• <source_file> is the path to your main .scy Scythe source file
• [output_file] (optional) is the path to where the generated .jsfx file should be saved. If omitted, it will generate the output in the current directory with a default name.

To use a JSFX plugin in REAPER, it must be placed in the REAPER/Effects/ directory. Once there, it will appear in the FX list.

Documentation can be found here.
Examples can be found here.

For syntax highlighting in Vim or Neovim, there is a mostly-working vimscript that uses Treesitter available here.

Requirements

• CMake
• Visual Studio with "Desktop development with C++"

1. git clone or download the repo
2. Open a terminal in the repo and run

mkdir build && cd build && cmake .. && cmake --build . --config Release

This will generate a scythe.exe executable somewhere in the newly created build folder, usually in build\Release.

Requirements

• CMake
• Make

1. git clone or download the repo
2. Open a terminal in the repo and run

mkdir build && cd build && cmake .. && cmake --build . --config Release

This will generate a scythe executable in the newly created build directory.