8f4e
8f4e is a stack-oriented programming language designed for real-time audio synthesis, with a visual code editor built for live coding and experimentation.
I started it as a recreational programming project during the COVID-19 lockdown to perform generative music at algorave events.
Its primary target is the WebAssembly virtual machine, as I wanted an efficient yet portable tool for real-time audio signal generation and processing.
Stack-oriented programming
Stack-oriented programming means that instead of using registers, instructions take their operands from a stack and push their results back onto the same stack for the next instruction to consume.
I chose this programming paradigm because the WebAssembly virtual machine is itself a stack machine.
Staying native to this execution model avoids costly abstractions and makes it possible to write faster programs compared to typical WebAssembly-targeting languages.
... 021 push 2 022 push 3 023 ; Pushing values 2 and 3 024 ; onto the stack. 025 add 026 ; After executing the 027 ; add instruction, 028 ; the stack will contain 029 ; the value 5 030 push 10 031 mul 032 ; Now the stack will 033 ; contain the value 50 034 push 10 035 div 036 ; Now 5 again ...
Memory access and pointers
Unlike in most programming languages, memory addresses in 8f4e are determined by the compiler and inlined at compile time.
This allows direct memory access with pointers, without requiring an additional indirection layer such as a heap or garbage collector.
... 021 int result 022 push &result 023 ; The variable name 024 ; prefixed with & 025 ; gives its memory address. 026 push 42 027 store 028 ; The store instruction 029 ; takes two values: 030 ; a memory address 031 ; and the value to store. ...
Sequential memory layout
All memory items are laid out sequentially in memory, so variables declared one after another occupy adjacent memory locations.
They are aligned on a 32-bit grid, which means every memory item starts at an address that is a multiple of 4 bytes.
... 021 int a 42 022 023 float b 3.14 024 ; Memory address of b 025 ; is address of a + 4 026 027 int c -5 028 ; Memory address of c 029 ; is address of b + 4 ...
Live variable editing
8f4e supports real-time editing of variable values while a program is running, without recompilation.
This is made possible by the deterministic allocation strategy: because memory addresses are fixed at compile time, the compiler can provide the exact address of every memory item, allowing the editor to locate and update any variable directly.
... 021 int foo 10 022 ; You can change these 023 ; values in the editor 024 ; while the program is running. 025 float bar 3.14 026 ; The editor will trace 027 ; them back in the memory 028 ; and update their values 029 ; without restarting 030 ; or recompiling the program. ...
Modules and execution order
The code is organized into modules, each containing variable declarations and a sequence of commands.
The execution order of the code modules is determined by their dependencies. If a module's output is needed as input for others, it is executed first.
... 021 module foo 022 023 int a 10 024 int b 20 025 int result 026 027 push &result 028 push a 029 push b 030 add 031 store 032 033 moduleEnd ...
Public variables and pointer iteration
All variables in 8f4e are inherently public, with no option to modify visibility.
8f4e is not memory-safe, pointers can point to anything within the memory space of the program, but the visual wires help developers to find where their pointers are pointing.
... 021 int* pointer 022 023 push &pointer 024 push pointer 025 push 4 026 push add 027 store 028 ; pointer will iterate through 029 ; memory in 4-byte steps. ...
