nyl

An interpreted stack language.

Operators

Operator	Stack	Effect
ADD	a b -- a+b
DUP	a -- a a
MUL	a b -- a*b
SUB	a b -- a-b
DIV	a b -- a/b
OUT	a --	prints the unicode code point
EXIT	a --	exits with the exit code
DEF		starts a macro definition
END		ends a macro definition
EQU	a b --	if a == b, the next word is evaluated, otherwise it is skipped
JMP	| a --	jumps to the position on the return stack

Labels

A word starting with @ defines a label. A word starting with ! will jump execution to that label. A word starting with % will jump execution to that label and and push the current postion onto the return stack.

Macros

Macros are ways to define words that expand to a set of instructions.

For example:

DEF square DUP MUL END

6 square

During the macro expansion phase 6 square will be replaced with 6 DUP MUL.

TODO

Stack

• swp
• pop

Logic

• neq

Data

• heap (a bigger place for accessing data by address)