PUSH

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PUSH
Designed by Expliked
Appeared in 2020
Memory system Stack-based
Computational class Unknown
Major implementations https://github.com/expliked/PUSH
File extension(s) *.txt


PUSH is an esoteric programming language created by User:Expliked in November 2020. It is a stack-based language.

Syntax

Keyword Meaning
PUSH: (integer); Pushes the given value to the stack.
ADD: (integer); Adds the given value to the last value of the stack.
SUBTRACT: (integer); Subtracts the given value to the last value of the stack.
PULL; Outputs the first value from the stack, then removes it.
INPUT; Prompts for user input. Each individual character will be stored in the stack.
DO; Starts a do-while loop. A do-while loop cannot be created inside another do-while loop.
WHILE; The end of a do-while loop. If the last value of the stack is 0, it will jump back to the DO; statement.
CLEAR; Clears the stack.
[ Denotes the start of a comment.
] Denotes the end of a comment.

Code structure

In PUSH, spaces, newlines, carriage returns, and tabs are ignored.

All keywords must have a ; after them.

Examples

Simple Hello, World! program:

PUSH: 72;
PUSH: 101;
PUSH: 108;
PUSH: 108;
PUSH: 111;
PUSH: 44;
PUSH: 32;
PUSH: 87;
PUSH: 111;
PUSH: 114;
PUSH: 108;
PUSH: 100;
PUSH: 33;
PUSH: 10;

[Output all characters:]
DO;
    PULL;
WHILE;

Breaking down "Hello, World!"

The PULL keyword will output the first value of the stack, then delete that value. It then shifts all values after it to the left. After we are done pushing all of our values to the stack, this is what it will appear as:

H   e    l    l    o    ,  " "  W    o    r    l    d   !   \n
72, 101, 108, 108, 111, 44, 32, 87, 111, 114, 108, 100, 33, 10

After the first PULL is used, the stack looks like this:

e    l    l    o    ,  " "  W   o    r    l    d    !   \n
101, 108, 108, 111, 44, 32, 87, 111, 114, 108, 100, 33, 10

If you repeat this process you will have eventually printed out all characters.

Instead of doing PULL after every PUSH, we can just use DO; PULL; WHILE;. This will output every character until there are no more left.

More examples

Cat program (expects at least one character of input):

INPUT;
DO;
    PULL;
WHILE;

99 Bottles of Beer:

https://pastebin.com/TQVxJT9v

External resources