= new OK virtual machine assembly language - mk2asm (or just "MK 2")

Note: `MK` is pronounced "mark".

== Basic assembly opcodes:

- `ADD` 
- `AND`
- `XOR` 
- `SHF` 
- `CMP` 
- `SWP` 
- `STR` 
- `LOD` 
- `DUP` 
- `DRP` 
- `PSH` 
- `POP` 
- `JMP` 
- `INT`
- `NOP`

These can be optionally suffixed by a number from 1-4 to represent what size 
integers the word operates on (1, 2, 3, or 4 bytes).

== Hex literals:

`#` followed by (case-insensitive) hex digits. Must be either 2, 4, 6, or 8 digits.

== Halt keyword

The `HLT` keyword can be used like an instruction that stops execution of the
CPU- being represented in bytecode as a 0-byte, which terminates execution.

It cannot make use of any skip flags or number suffixes.

== comments

Comments are like in FORTH; any text between `(` and `)` gets ignored.

== Skip flag suffix

All instructions can optionally have a "?" suffix at the very end, with the
exception of `HLT`. An example:
`#ff?`
`ADD4?`

== labels

`.label` declares a label, and `@label` pushes that label's value to the stack.

Labels are accessible throughout the entirety of the file, even before they have
been declared.

== macros

New words can be defined with macros:

`%def INCREMENT 1 ADD %end`

Labels declared within the `%def` get mangled.

The following rules govern what characters can be used in user-defined words:

- They cannot start with `#`, `@`, `.`, or `%`
- They cannot contain `(` or `)`
- They cannot contain white space
- They cannot be an existing instruction

Macros are accessible at any point *after* their definition.

Macros cannot be defined within the bodies of other macros.