Reference guide

This document applies to version 1.3 beta.

Words

Constants:

false true

Math:

1- 1+ + - * / mod negate abs max min ln exp sqrt cos sin trunc round
random randomize

Logic:

>= > <> = <= < not or and

I/O:

. cr ( ) refill include emit space spaces char

Facility extension:

	ms

Stack:

drop dup swap 2dup over

Definitions and variables:

@ ! variable constant value to : ;

Comments:

/* */ \

Control structures:

{ } [ ] iffalse iftrue times repeat until while interpret

Interactive use:

.s words see forget depth bye

Internals

• F-Lower doesn’t have a return stack; it piggybacks on the host language.
• Conversely, it has a word stack so it can handle variables and such.
• Words are stored uniformly; execution tokens are simply callback procedures.
• Similarly, the def_* procedures are just factories that set the right fields.

Compilation state is replaced with a uniform buffering system that also works outside colon definitions, and powers control structures too.