:   ;   [   ]   ;i   ;EXIT   IMMED?   IMMEDIATE   :NONAME   STATE

:

The word : is the most used creation word in FORTH.

It defines a word <nom> called "colon" word in the form:

: NAME  nomex1 nomex2 ... nomexn ;
NAME  \ execute NAME

Subsequent execution of NOM performs the execution sequence words compiled in his "colon" definition.

After : NOM, the interpreter enters compile mode. All non-immediate words are compiled in the definition, the numbers are compiled in literal form. Only immediate words or placed in square brackets (words [ and ]) are executed during compilation to help control it.

A "colon" definition remains invalid, ie not inscribed in the current vocabulary, as long as the interpreter did not execute ; (semi-colon).

;

Immediate execution word usually ending the compilation of a "colon" definition:

: NAME
    nomex1 nomex2 ... nomexn ;

[ ( ---)

Enter interpretation state. [ is an immediate word.

: [ 
    0 state ! 
    ; immediate

] ( ---)

Return to compilation. ] is an immediate word.

With FlashForth, the words [ and ] allow you to use assembly code, subject to first compiling an assembler. Example:

\ Load constant $1234 to top of stack  
: a-number ( -- 1234 )
    dup                  \ Make space for new TOS value
    [ R24 $34 ldi, ]
    [ R25 $12 ldi, ]
;

: ] 
    -1 state ! 
    ; immediate

;i

Specific Flash Forth

Immediate execution word completing the compilation of a "colon" definition but intended to be used through an interruption:

\ The interrupt routine
variable counter
: t3OverflowIsr ( ---)
    1 counter +!                    \ increment counter
;i

 ATTENTION : the word t3OverflowIsr should not be performed in interpretation, but only through an interruption.

EXIT ( ---)

Aborts the execution of a word and gives back to the calling word.

Typical use: : X ... test IF ... EXIT THEN ... ;

At run time, the word EXIT will have the same effect as the word ;

WARNING in FlashForth, do not run EXIT in a FOR..NEXT loop.

IMMED? ( addr -- n )

Leave a nonzero value if addr contains a immediate flag.

IMMEDIATE ( ---)

Make the most recent definition an immediate word.

sets the compile-only lexicon bit in the name field of the new word just compiled. When the interpreter encounters a word with this bit set, it will not execute this word, but spit out an error message. This bit prevents structure words to be executed accidentally outside of a compound word.

NONAME: ( --- cfa-addr)

Define headerless forth code. cfa-addr is the code execution of a definition.

Exemple

:noname s" Saterday" ;
:noname s" Friday" ;
:noname s" Thursday" ;
:noname s" Wednesday" ;
:noname s" Tuesday" ;
:noname s" Monday" ;
:noname s" Sunday" ;
 
create (ENday) ( --- addr)
	, , , , , , ,
 
:noname s" Samedi" ;
:noname s" Vendredi" ;
:noname s" Jeudi" ;
:noname s" Mercredi" ;
:noname s" Mardi" ;
:noname s" Lundi" ;
:noname s" Dimanche" ;
 
create (FRday) ( --- addr)
	, , , , , , ,
 
defer (day)
 
: ENdays 
    ['] (ENday) is (day) ;
 
: FRdays 
    ['] (FRday) is (day) ;
 
3 value dayLength
: .day	
    (day)
    swap cell *
    + @ execute
    dayLength ?dup if
        min
    then
    type
;
ENdays
0 .day \ display Sun 
1 .day \ display Mon 
2 .day \ display Tue 
FRdays  ok
0 .day \ display Dim 
1 .day \ display Lun 
2 .day \ display Mar 

POSTPONE ( comp: -- <name> )

Skip leading space delimiters. Parse name delimited by a space. Find name. Append the compilation semantics of name to the current definition.

STATE ( --- flag)

Compilation state. State can only be changed by [ and ]