pass a symbol
pass a symbol or PAS (lol) is an esolang where the whole idea is you can make your own commands. Although this should not be considered a metalang (I think), it is a category anyway.
How It Works
You start by putting a top binary number, then a symbol, and then another binary digit, like this:
0 E 1
This defines E, which will take input as a binary number and output another one. If it has input 0, it will output 1. BUT this does not mean that passing 1 gives 0. Since that's not defined, passing a 1 to E will give 1. To define a NOT gate with symbol E, it would be:
0 E 1 - 1 E 0
This defines a NOT gate, and a - separates these definitions. There is a special symbol that can replace a binary digit, which is i. This symbol will take user input as a binary digit (or digits). For example, like this:
i E 0
Adding a o at the end of a binary digit at the bottom of a definition will make it output itself. To make it output in Unicode, a $ is used instead:
0 E 1 # 0 E o
Also, # separates definitions from the calculation. To make an operator pass the result it makes to itself recursively, a ^ is used at the start of the first definition, and if there is a state that ends in * it will break out of recursion, which will make it pass the result to itself. If you want it for a spesific output it can replace the input of a function. If this is done ~ Will break the loop. Putting an X at input will make it halt itself. One last thing: there is a tape extending infinitely to the right. > and < move around the tape, ( is o but on the current cell, and ) is $ (these only work after the # or in the output of a definition). Putting a % at the end of the output in a definition will put that into the tape, and putting a * instead of a binary number in the # section will take the current tape cell.
examples
^ 0 E 0oX - 1 E 11o - 11 E 1o # i E
infinite loop:
^ 0 E 0 # 0 E
Double layer buffer:
0 ¬ 1 - 1 ¬ 0 # 0 ¬ ¬
logic gates
AND
01 A 0 - 10 A 0 - 00 A 0 - 11 A 1 # 11 A
OR
10 R 1 - 01 R 1 - 11 R 1 - 00 R 0 # 11 R
NOR
10 R 1 - 01 R 1 - 11 R 1 - 00 R 0 -
0 ¬ 1 - 1 ¬ 0 # 11 R ¬
NAND
01 A 0 - 10 A 0 - 00 A 0 - 11 A 1 - 0 ¬ 1 - 1 ¬ 0 # 11 A ¬
XOR
10 X 1 - 01 X 1 - 11 X 0 - 00 X 0 # 11 X
XNOR
10 X 1 - 01 X 1 - 11 X 0 - 00 X 0 - 0 ¬ 1 - 1 ¬ 0 # 11 X ¬
notes
- im not sure if this is even possible but isn't this both imperative and declarative?
- im pretty sure this is NOT turing complete