Stacky is a stack based interpreted language that I made in a few hours as a stepping stone in my journey to interpreters. Stacky is a simple language, only compromising of 21 instructions with 18 of them requiring no operands at all and the stack being 64 kilobytes in size.
The instructions are as follows
| Instruction | Description |
| PUSH | Pushes the byte value provided into the stack |
| POP | Pops the last value pushed from the stack |
| POPP | Pops the last value pushed from the stack and prints out the integer |
| POPPC | Pops the last value pushed from the stack and prints out the ASCII character |
| INC | Pops the last value pushed from the stack, increments it, and pushes it back into the stack |
| DEC | Pops the last value pushed from the stack, decrements it, and pushes it back into the stack |
| ADD | Pops the last two values from the stack, adds them, and pushes the result into the stack |
| SUB | Pops the last two values from the stack, subtracts them, and pushes the result into the stack |
| MUL | Pops the last two values from the stack, multiplies them, and pushes the result into the stack |
| DIV | Pops the last two values from the stack, divides them, and pushes the quotient into the stack |
| MOD | Pops the last two values from the stack, divides them, and pushes the remainder into the stack |
| COPY | Pops the last value from the stack and pushes it two times into the stack |
| CCF | Clears the conditional flag |
| CMPE | Pops the last two values from the stack and compares them, if they are equal the conditional flag is set to true |
| CMPL | Pops the last two values from the stack and compares them, if the first value is smaller than the second the conditional flag is set to true |
| CMPG | Pops the last two values from the stack and compares them, if the first value is bigger than the second the conditional flag is set to true |
| JC | Jumps to the specified line if the conditional flag is set to true |
| JMP | Jumps to the specified line |
| RPUSH | Read a key character from the keyboard as input and pushes the value into the stack |
| NEWL | Prints a new line character |
| HAULT | Stops the program and sets the exit code equal to the value provided |