hxal

Haxe Audio Language. A haxe-based DSL for real-time audio applications built using haxe's macro system. Part of grig.

EARLY STAGE OF DEVELOPMENT. Ignore if you are expecting something you can use right away. Other parts of grig can be used now (grig.midi, grig.audio) but not this.

Design Goals

• Look and behave like haxe
• Lightweight and simple
• Facilitates two different compilation pathways:
  • Straightforward compilation as haxe code with minimal modification by the macro aside from swapping hxal types for grig types
  • Transpilation straight to non-garbage-colleged targets. Planned:
    • soul
    • rust
    • c/c++
• Allows declaration of variables, assignments, arithmetic but prevents allocations and frees, ensuring that the code is suitable for realtime even on gc targets.
• Meant to be easy to port legacy c++ code to, rather than being a radically different paradigm like faust
• Err on the side of simple and works, rather than being clever
• Designed to build atop other's work, in keeping with the general philosophy of haxe.
• All errors should be caught by VSCode and others' error checking. This is just haxe code, after all!
• Per frame and per midi event interface, which easily transforms to soul and, with hxal adding loops, to all the other environments

Dual Code Paths

graph TD;
    code[hxal code]-->ast[hxal AST]
    ast-->haxe[haxe code with grig]
    ast-->codegen[hxal code generator]
    codegen-->soul
    codegen-->rust
    codegen-->cpp[C/C++]
    codegen-->dotdot[...]
    cpp-.->standalone(standalone)
    cpp-.->vst(vst)
    cpp-.->lv2(lv2)
    cpp-.->plain(source code)
    cpp-.->dotdotdot(...)
    haxe-->std[normal haxe compilation path]

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Overview

To create a node that does processing - it can be an instrument or an effect - by creating a class that extends grig.hxal.Node. This will automatically bring in the macros that check the code and, as needed, use it to generate code.

import grig.hxal.Node;

class SineSynth extends Node
{
}

hxal extensively uses compiler metadata for supplying information to different plugin formats. You may add any number of names, along with the ISO 639-1 language code for the translation and a version to the class:

@name("Sine Synth", 'en')
@name("サインシンセサイザー", 'jp')
@version("0.0.1")
class SineSynth extends Node

In a Node class, you can have variables and functions, with some limitations. Currently, access modifiers aren't supported for simplicity (it has no meaning in plugins or non-oo targets). But final keyword is (and encouraged!) All variables, whether class members or defined in functions must be one of the following types:

• Int
• UInt
• Int8
• UInt8
• Int16
• UInt16
• Int32
• UInt32
• Int64
• UInt64
• Float
• Float32
• Float64
• Sample
• Array<Type, Length> in variable declarations or Array<Type> in arguments
• Bool

Int and UInt alias to whatever is the fastest int type on the architecture, same with Float. Sample is whichever format is used for audio samples, which doesn't necessarily map to another type on the list.

Class member variables can be marked as parameters using metadata:

@parameter
@name("OSC1 Frequency", 'en')
var frequency1:Float;

As with the class itself, multiple name, language code pairs are supported for translations.

@parameter @name("OSC1 Frequency", 'en') var frequency1:Float;