CF - a ColorForth and Tachyon inspired system

ColorForth influences on CF

• NOTE: cf is a work in progress. Please collaborate with me on it!
• cf is inspired by ColorForth, but it is NOT ColorForth.
• cf has 4 states: DEFINE, INTERPRET, COMPILE, and COMMENT.
• cf uses markers in the source to control its state.
• cf has a and b registers like ColorForth. It also has a t register.
• cf supports using either a byte in the whitespace or a word to change the state.

Whitespace characters and WORDS that change the state:

Byte	Word(s)	New State
$01	":"	DEFINE
$02	"]" or ")"	COMPILE
$03	"[" or "))"	INTERPRET
$04	"(" or "(("	COMMENT
	";"	INTERPRET

Notes:

• DEFINE changes the state to COMPILE after adding the word to the dictionary.
• ";" compiles EXIT and changes the state to INTERPRET.
• There is no difference between ( and ((, they make the code more readable.
• CF still supports IMMEDIATE words.
• Flow control words like IF/THEN would be marked as IMMEDIATE.
• They are defined in the source file.

(( A comment in INTERPRET mode ))
: hello ( A comment in COMPILE mode ) ." Hello World!" ;
hello

Tachyon's influence on cf

In cf, a program is a sequence of OPCODEs.
An OPCODE is a CELL-sized unsigned number (32 or 64 bits).
Primitives are assigned numbers sequentially from 0 to (bye).
If an OPCODE is less than or equal to (bye), it is a primitive.
If the top 3 bits are set, it is an unsigned literal with the top 3 bits masked off.
Else, it is the CODE slot of a word to execute.
CODE slots 0-24 are used by cf.
CODE slots 25-(bye) are free CELL-sized slots that can be used for any purpose.
HERE starts at (bye)+1.

Architecture

CF is really just a Forth VM, upon which any Forth system can be built.
To that end, cf provides a set of primitives and the inner/outer interpreters.
See cf.c for the list of primitives. The rest of the system is defined by the source code file.
CF takes a source file as its only argument.
If cf is executed without arguments, the default source file is 'boot.fth'.
CF provides a single chunk of memory (see cf.h, MEM_SZ) for data and code.
The CODE area starts at the beginning of the memory.

Embedding cf into a C program

CF can easily be embedded into a C program.
The cf VM is implemented in cf.c.
The configuration and API for cf are located in cf.h.
That is what system.c does, it creates a C program around the cf VM.

Building cf

Building cf is simple and fast since there are only 3 small source files.

Windows

• There is a cf.sln file for Visual Studio. 32-bit or 64-bit builds are supported.

Linux, OpenBSD, and FreeBSD

• There is a makefile, which uses the system C compiler (specified by the CC variable).
• Or you can easily build cf from the command line:
• Example:

# default, 64 bit:
make

# for 32 bit:
ARCH=32 make

# or manually:

$CC -m32 -O3 -o cf *.c
$CC -m64 -O3 -o cf *.c

Blocks

• Blocks are not native to cf.
• They are implemented in the default source file.

The Editor

• A block editor is implemented in the default source file.