StackSwap

StackSwap is an esolang by User:Fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff designed around function calls.

Syntax

A StackSwap program is a series of function definitions, which start with the function name, then a colon, and finally a list of function calls.

Semantics

StackSwap contains two stacks, one of which is selected to be the current stack, as well as an instruction pointer. When a function is called the function calling it is placed onto the current stack and control moves to the called function.

Built-in methods

• §: Swap the two control stacks. Note that this method returns to the function it was called from normally.
• out1: Send a 1 to the little-endian output buffer. When the buffer has eight bits, output that byte to stdout.
• out0: Send a 0 to the little-endian output buffer. When the buffer has eight bits, output that byte to stdout.
• read: Remove a bit from the front of the little-endian input buffer and execute § if it is a 1. If the buffer is empty, input a byte to the buffer.

Examples

Hello, World!

a: out1 out0 out0 out1 out0 out0 out0 out1 out1 out0 out0 out1 out0 out1 out1 out1 out0 out1 out1
b: out0 out0 out1 out1 out0 out1 out1 out0 out0 out1 out1 out0 out1 out1 out1 out1 out1 out0 out1
c: out1 out0 out0 out1 out0 out0 out0 out0 out0 out1 out0 out1 out0 out1 out1 out1 out1 out1 out0
d: out1 out1 out1 out1 out1 out1 out1 out0 out0 out1 out0 out1 out1 out0 out1 out1 out0 out0 out1
e: out1 out0 out0 out1 out0 out0 out1 out0 out0 out0 out0 out1 
main: a b c d e

Truth-machine

waste: read read read read read read read
next: read § a
zero: § next out0 out0 out1 out1 out0 out0 out0 out0
main: waste next one
one: out0 out0 out1 out1 out0 out0 out0 out1 one