stak

a forth-y livecoding audio doodad

heavily inspired by sporth, with an aim to be like ProxySpace

it is a tiny stack-based language similar to forth

# howdy there :)
freq: 0.3 sin bi2norm 880 *

wave: freq saw

noise: 1000 1 buffer fill_noise

x: (wave) (1 noise play 0.5 *) + out

key terminology:

• value: a basic unit used by operations:

  • a number
  • a pointer to something

• stack: a stack of values

• atom: a basic operation:

  • a string (push a string)
  • a number (push a number)
  • a pointer to a variable (append all values from that variable's stack onto the current)
  • a function (see below)

• procedure: a list of atoms, and an process type (how often it should be processed)

• function: these are complicated atoms that can perform a variety of tasks

  • may have an "init" function, which is called when the atom is created
  • may have a "deinit" function, which is called when the atom is destroyed
  • may have a "process" function, which is called when the atom is processed
  • may have some dynamic data, which can be allocated/freed by the init/deinit functions and used by the process function
  • for example:
    • add: no init, no deinit, no data, process(a,b) = a + b
    • buffer: init will allocate a buffer, deinit will free the buffer, data stores the buffer_t struct, process(len,chans) = resizes buffer to len and chan
    • sin: init will allocate an oscilator, no deinit (data is automatically freed), data stores the oscil_t struct, process(freq) = increments oscilator by the given frequency

• variable: these are defined by "name: body", and consist of a stack and a procedure that is applied to that stack

• out: this is a function that pops values to the audio output

• in: similarly, this pushes the audio input to the stack

• comments: they start with a # and take up the whole line, or until another #

• brackets/parenthesis/tabs/newline: these are completely ignored, use them to split up your code however you see fit

interacting

this section needs work :)

currently, type "r" to reload example.st, "q" to quit, enter to print current state. otherwise, input is evaluated.

build requirements

• ansi c compiler
• make
• jack