Forth ===== This is a new implementation of Forth 2012 in C. Building & use -------------- Use cmake or `build.sh`. It probably needs GCC with `--std=gnu99`. You get a binary with the forth runtime. Run it to get a prompt. Use `-h` for help. Goals ----- - Comfy to use and extend - No dynamic allocation where possible - Compact and embeddable so it can be ported to ARM-CortexM or similar later - Implement the CORE and CORE-EXT word sets, for a start - Pass the [Forth2012 test suite](https://github.com/gerryjackson/forth2012-test-suite), at least for the word sets that are implemented - Maybe eventually have some terminal-based implementation of (a subset of) the Facility word set, like AT-XY and keyboard input - Try to keep added custom words and quirks at a minimum - Comment stuff, maybe Non-Goals --------- - I don't really care about implementing some of the word sets - Performance is not so critical for a hobby Forth like this - Probably won't accept merge requests, this is my Forth - I also don't care about someone telling me to add a license file Custom words ------------ - `.\"` - like `."` but allows escaping, this is essentially `S\" blah" TYPE`, but without allocation (unless compiled) - `??` - debug dump of the stacks - `reset` - everything should become like if you restarted the program - `debug ( flag -- )` - enable or disable verbose logging For debug, there is `see ( "word" -- )` that lets you inspect and disassemble dictionary entries. Implementation status --------------------- *(this section may be outdated)* Implemented (some may be wrong, like `FM/MOD`): ``` CORE: ! ' ( * */ */MOD + +! +LOOP , - . ." / /mod 0< 0= 1+ 1- 2! 2* 2/ 2@ 2DROP 2DUP 2OVER 2SWAP : ; < = > >IN >R ?DUP @ ABORT ABS ALIGN ALIGNED ALLOT AND BASE BEGIN BL C! C, C@ CELL CELL+ CELLS CHAR CHAR+ CHARS CONSTANT COUNT CR CREATE DECIMAL DEPTH DO DOES> DROP DUP ELSE EMIT ENVIRONMENT? EXECUTE EXIT FM/MOD FIND HERE I IF IMMEDIATE INVERT J LEAVE LITERAL LOOP LSHIFT M* MAX MIN MOD NEGATE OR OVER POSTPONE QUIT R> R@ RECURSE REPEAT ROT RSHIFT S>D S" SM/REM SOURCE SPACE STATE SWAP THEN TYPE U< UNTIL UM* UM/MOD UNLOOP VARIABLE WHILE WORD XOR [ ['] [CHAR] ] CORE-EXT: .( :NONAME 0<> 0> 2>R 2R> 2R@ <> ?DO AGAIN FALSE HEX NIP PAD PICK ROLL S\" TO TRUE TUCK U.R U> UNUSED VALUE \ Other sets: FORGET SEE BYE ``` Missing: basically, CASE-OF, pictured numbers, keyboard input, some weirder metaprogramming things, manipulating the input buffer. ``` CORE: # #> #S <# >BODY >NUMBER ABORT" ACCEPT EVALUATE FILL HOLD KEY MOVE SIGN SPACES U. CORE-EXT: .R ACTION-OF BUFFER: C" CASE COMPILE, DEFER DEFER! DEFER@ ENDCASE ENDOF ERASE HOLDS IS MARKER OF PARSE PARSE-NAME REFILL RESTORE-INPUT SAVE-INPUT SOURCE-ID WITHIN [COMPILE] ``` .