retroforth/doc/Cross-Reference.md

Forth to RETRO Cross Reference

This is a quick overview of some differences between RETRO and traditional Forth.

Category	Forth	RETRO
Definitions	: name ;	:name ;
Numbers	100 -12	#100 #-12
Characters (interpret)	CHAR A CHAR D	$A $D
Characters (compile)	[CHAR] A [CHAR] D	$A $D
Comments	( This is a comment )	(This_is_a_comment)
Pointers (interpret)	' Compiler	&Compiler
Pointers (compile)	`['] Compiler	&Compiler
Conditionals #1	IF 1 THEN	[ #1 ] if
Conditionals #2	NOT IF 1 THEN	[ #1 ] -if
Conditionals #3	IF 1 ELSE 2 THEN	[ #1 ] [ #2 ] choose
Counted Loops	10 0 DO LOOP	#10 [ ] times
Counted Loops w/Index	10 0 DO I LOOP	#10 [ I ] indexed-times
Unconditional Loops	BEGIN AGAIN	repeat again
Return Stack	10 >R ... R>	#10 push ... pop

RETRO conditionals and loops can be used outside of definitions, ANS ones can not.

Some forms are replaced by combinators.

FORTH
>R ... R>       [ ... ] dip
DUP >R ... R>   [ ... ] sip