Huw's Stack Machine

A basic stack machine implemented in Rust.

Instructions

int = integer number float = float number

Stack contains a list of integers. We run an instruction to interact with the stack. So for example push 1 will add 1 to stack list. pop will remove the top (value: 1) from the stack.

Instruction	Description
addi	Pop two off stack, add the two and push new value onto stack. Two numbers must be integer type.
subi	Pop two off stack, subtract the two and new value push onto stack. Two numbers must be integer type
muli	Pop two off stack, multiply the two and new value push onto stack. Two numbers must be integer type
divi	Pop two off stack, divide the two and push new value onto stack. Two numbers must be integer type
addf	Pop two off stack, add the two and push new value onto stack. Output will be float type.
subf	Pop two off stack, subtract the two and new value push onto stack. Output will be float type.
mulf	Pop two off stack, multiply the two and new value push onto stack. Output will be float type.
divf	Pop two off stack, divide the two and push new value onto stack. Output will be float type.
pushi <INT>	Push int onto stack.
pushf <FLOAT>	Push int onto stack.
pop	Pop int off stack.
inputi	Read user input as int.
inputf	Read user input as float.
print	Print top of stack.
printl	Print top of stack.
printa	Print top of stack as an ASCII character.
label <LABEL>	Used as locations for jumps.
j <LABEL>	Jump to label.
je <LABEL>	Jump to label if equal.
jn <LABEL>	Jump to label if not equal.
jg <LABEL>	Jump to label if greater than.
jge <LABEL>	Jump to label if greater than or equal to.
jl <LABEL>	Jump to label if less than.
jle <LABEL>	Jump to label if less than or equal to.
toi	Convert top of stack to integer.
tof	Convert top of stack to float.
dup	Duplicates top of stack.

Process of jump

1. Compare two top items on stack
2. Pop top of stack
3. Jump to label if comparison is true, otherwise, we carry onto next line.

Example

pushInt 0
label main
printLine
pushInt 1
addi
push 10
jl main

The example above prints a list of numbers from 0 to 9.

Usage

cargo build
cargo run FILENAME