<< Home | About Forth | About TurboForth | Download | Language Reference | Resources | Tutorials | YouTube >>
; _____ _ _ _ __ __ _ ; / ____| (_) (_) \ \ / / | | ; | | ___ _ __ ___ _ __ _| |_ _ __ __ _ \ \ /\ / /___ _ __ __| |___ ; | | / _ \| '_ ` _ \| '_ \| | | | '_ \ / _` | \ \/ \/ // _ \| '__/ _` / __| ; | |____| (_) | | | | | | |_) | | | | | | | (_| | \ /\ /| (_) | | | (_| \__ \ ; \_____|\___/|_| |_| |_| .__/|_|_|_|_| |_|\__, | \/ \/ \___/|_| \__,_|___/ ; | | __/ | ; |_| |___/ ; Compilation words... ; HEADER ( TIB:string -- ) ; creates a word (from the input source) in the dictionary and links the ; dictionary ; ********************************************************************* ; NOTE: FOR VERSIONS 1.2.1 ONWARDS: ; HEADER NOW DOES A "BL WORD" SEQUENCE INTERNALLY. ; NO NEED TO DO A "BL WORD HEADER" SEQUENCE IN CODE THAT USES HEADER. ; HEADER NOW DOES IT FOR YOU. ; ********************************************************************* headrh data byeh,6 text 'HEADER' header data docol data align ; ensure HERE is aligned data spword ; get a word from the input source data headr ; create and link new dictionary entry data exit headr data $+2 bl @bank1 data _headr ; see 1-09-Compilation.a99 ; MARKER ( -- ) ; creates a marker in the dictionary that, when executed, removes all words ; following the marker from the dictionary, and resets the compilation address ; to the first free address following the marker. ; Example: ; MARKER RESET \ create a marker called reset ; : test1 1 2 3 ; \ define some words ; : test2 4 5 6 ; ; : test3 7 8 9 ; ; RESET ; In the example above, upon execution of RESET, the words test1 test2 & test3 ; are removed from the dictionary, LATEST points to the link field of RESET and ; H points to the next cell after the end of the definition of RESET. ; FFAIHM & FFAILM are also updated. markrh data headrh,6 text 'MARKER' markr data docol data header data compile,docol data compile,domark data lates_,fetch,comma data ghere,lit,6,add,comma ; branch to code in FORGET to force update of FFAILM & FFAIHM... data compile,align data compile,exit data exit domark data $+2 mov *pc+,@latest mov *pc+,@here b *next ; CREATE -- M,79 ; A defining word executed in the form: ; CREATE; Creates a dictionary entry for . After ; available dictionary location is the first byte ofis created, the next 's parameter field. ; Whenis subsequently executed, the address of the first byte of ;'s parameter field is left on the stack. ; CREATE does not allocate space in's parameter field. creath data markrh,6 text 'CREATE' create data docol data header ; create and link dictionary entry data compile,crtime ; compile create's run-time to CREATEd CFA data exit ; the run-time behaviour of all words created with CREATE is to leave their PFA ; on the stack... Children of CREATE invoke the following code, called by the ; inner interpreter: crtime dect stack ; make room for PFA mov r6,*stack ; place PFA on stack b *next ; patches CFA of last created word with address of run-time code of parent. ; address contained in PATCH. Used by DOES> altcfa data $+2 mov @patch,r0 ; CFA of most recent definition mov pc,*r0 ; patch it with parent's code field mov *rstack+,pc ; in-line EXIT that "ends" the definition b *next ; into which altcfa is compiled ; DODOES ; dynamically compiles instructions (for run-time transition from child to ; parent for DOES> words) into the parent DOES> word. dodoes data docol data compile,>0644 ; compile: "dect stack" instruction data compile,>C506 ; compile: "mov r6,*stack" instruction data compile,>0645 ; compile: "dect rstack" instruction data compile,>C543 ; compile: "mov pc,*rstack" instruction data compile,>0203 ; compile: "li pc,xxx" instruction ; calculate & compile address of xxx for li instruction: data ghere,lit,4,add,comma data compile,>045C ; compile "b *next" instruction data exit ; DOES> -- addr C,I,83 "does" ; -- (compiling) ; Defines the execution-time action of a word created by a high-level defining ; word. ; Used in the form: ; :... ... DOES> ... ; ; and then ; ; where is CREATE or any user defined word which executes CREATE. ; ; Marks the termination of the defining part of the defining wordand ; then begins the definition of the execution-time action for words that will ; later be defined by. When ;is later executed, the address of 's parameter field is placed on the stack and then the sequence of words ; between DOES> and ; are executed. doesh data creath,immed+5 text 'DOES> ' does data docol,align,compile,altcfa,dodoes,exit ; CONSTANT 16b -- M,83 ; A defining word executed in the form: ; 16b CONSTANT; Creates a dictionary entry for so that when ; 16b will be left on the stack. consth data doesh,8 text 'CONSTANT' const data docol data header ; create and link dictionary entry data compile,docon ; compile reference to docon data comma ; compile in the value of constant as an ; argument to docon data exit ; children of constant run this code... docon dect stack ; make space on the data stack mov *r6,*stack ; push payload to the stack b *next ; VARIABLE -- M,79 ; A defining word executed in the form: ; VARIABLEis later executed, ; A dictionary entry for is created and two bytes are ALLOTted in its ; parameter field. ; This parameter field is to be used for contents of the variable. ; Whenis later executed, the address of its parameter field is placed ; on the stack. varh data consth,8 text 'VARIABLE' var data docol,create,lit0,comma,exit ; VALUE ( n -- ) ; A "value" is actually a variable, but with more friendly syntax. VALUEs work ; in conjunction with TO and +TO. (Perversely, they are implemented internally ; using constants!) ; A value can be initialised with a value at the time of creation: ; 10 VALUE TEN - creates a word that pushes 10 to the stack when executed. ; Note how the value was created and intialised at the same time. Using ; standard variables, we would have to do: ; VARIABLE TEN 10 TEN ! - two distinct steps. ; To get the value of the value, just execute it: ; 10 VALUE TEN TEN . 10 ok ; Values, once created can have their values changed with the TO command: ; 100 VALUE DELAY (creates a VALUE called delay with the value of 100) ; 55 TO DELAY (changes the value of DELAY to 55) ; Using standard variables, we would have to do: ; VARIABLE DELAY ; 100 DELAY ! ; 55 DELAY ! valueh data varh,5 text 'VALUE ' value data docol,const,exit ; no coolness here, it's just a constant, the coolness is in TO & +TO ; TO ( n -- ) ; Allows the value of an already created VALUE to be changed: ; 100 VALUE SETPOINT (create a SETPOINT value with the value of 100) ; 65 TO SETPOINT (change SETPOINTs value to 65) toh data valueh,immed+2 text 'TO' data docol,toutil,zbrnch,tohx ; runs if in compile state. In compile state, a number will be on the ; stack, so compile a reference to doto data compile,doto ; compile reference to "do to" data comma ; compile body address data exit ; runs in interpret state - write the value on the stack to the body ; address.... tohx data store,exit dotoh data toh,4 text '(TO)' doto data $+2 mov *pc+,r0 ; get in-line body address mov *stack+,*r0 ; move tos to values' body b *next ; +TO ( n -- ) ; Similar to TO above, but adds the value on the stack to the value. ; 100 VALUE SETPOINT (create a value called SETPOINT with the value 100) ; 25 +TO SETPOINT (changes SETPOINTs value to 125) addtoh data dotoh,immed+3 text '+TO ' data docol,ToUtil,zbrnch,addtox ; runs if in compile state. In compile state, a number will be on the ; stack, so compile a reference to dopto ("do plus-to") data compile,dopto ; compile reference to "do plus-to" data comma ; compile body address data exit ; runs in interpret state - write the value on the stack to the body ; address.... addtox data stadd,exit ptoh data addtoh,5 text '(+TO) ' dopto data $+2 mov *pc+,r0 ; get in-line body address a *stack+,*r0 ; pop and add tos to value in the values' body b *next ; common routine to get body and state. Used by TO and +TO save a few bytes by ; making it common, and no run time penalty since this bit of code executes at ; compile time. ; ( -- body state) ToUtil data docol,getword,tobody,state_,fetch,exit ; ALLOT w -- 79 ; Allocates w bytes in the dictionary. ; The address of the next available dictionary entry is updated accordingly. alloth data ptoh,5 text 'ALLOT ' allot data $+2 bl @bank1 data _allot ; see 1-09-Compilation.a99 ; LIT ( -- n ) ; places the literal number on the datastack lith data alloth,3 text 'LIT ' lit data _lit ; runs from 16-bit ram ; LITERAL -- 16b C,I,79 ; 16b -- (compiling) ; Typically used in the form: ; [ 16b ] LITERAL ; Compiles a system dependent operation so that when later executed, ; 16b will be left on the stack. literh data lith,immed+7 text 'LITERAL ' litral data docol data clc ; compile lit and value from stack data exit ; , 16b -- 79 "comma" ; ALLOT space for 16b then store 16b at HERE 2- . commah data literh,1 text ', ' comma data $+2 bl @bank1 data _comma ; see 1-09-Compilation.a99 ; C, (COMMA) ( value -- ) ; appends an 8 bit value, from the least significant byte of TOS to HERE. ; Here is incremented by ONE BYTE, not one WORD. ; For safety, use ALIGN to align HERE to a word boundary afterwards. ccommh data commah,2 text 'C,' ccomma data $+2 bl @bank1 data _comab ; see 1-09-Compilation.a99 ; ALIGN ( -- ) ; Aligns HERE to an even word boundary by rounding up if required ; Call it after using C! alignh data ccommh,5 text 'ALIGN ' align data $+2 bl @bank1 data _align ; see 1-09-Compilation.a99 ; [ -- I,79 "left-bracket" ; -- (compiling) ; Sets interpret state. ; The text from the input stream is subsequently interpreted. ; For typical usage see LITERAL . See: ] lbrakh data alignh,immed+1 text '[ ' lbrack data $+2 clr @_state ; set state to 0 b *next ; ] -- 79 "right-bracket" ; Sets compilation state. ; The text from the input stream is subsequently compiled. ; For typical usage see LITERAL . See: [ rbrakh data lbrakh,1 text '] ' rbrack data $+2 seto @_state ; set state to non zero b *next ; : -- sys M,79 "colon" ; A defining word executed in the form: ; :... ; ; Create a word definition for in the compilation vocabulary and set ; compilation state. ; The search order is changed so that the first vocabulary in the search order ; is changed so that the first vocabulary in the search order is replaced by the ; compilation vocabulary. ; The compilation vocabulary is unchanged. The text from the input stream is ; subsequently compiled. ;is called a "colon definition". ; The newly created word definition forcannot be found in the dictionary ; until the corresponding ; or ; ;CODE is successfully processed. ; An error condition exists if a word is not found and cannot be converted to a ; number or if, during compilation from mass storage, the input stream is ; exhausted before encountering ; or ;CODE. ; sys is balanced with its corresponding ; ; See: "compilation" "9.4 Compilation" colonh data rbrakh,1 text ': ' colon data docol ; reset error detection reference counts.... data lit,ifcnt,lit,sal-ifcnt,lit0,fill ; begin compilation... data in_,fetch ; save >IN data header ; create entry and link dictionary data lates_,fetch,hideme ; set *this* entry as hidden data in_,store ; restore >IN data spword,find ; see if word already exists. ; FIND won't find *this* instance! data lit,temp,store,drop ; store result in temp. used later by ; data compile,docol ; compile DOCOL data rbrack ; switch on compile mode data exit ; CODE: ( -- ) ; Defines a machine code word. codeh data colonh,5 text 'CODE: ' data docol data header data ghere,plus2,comma data litm1,lit,coding,store data exit ; ;CODE ( -- ) ; ends a machine code definition ecodeh data codeh,immed+5 text ';CODE ' ecode data docol data lit,>045c,comma,lit,coding,store0 data exit ; ; -- C,I,79 "semi-colon" ; sys -- (compiling) ; Stops compilation of a colon definition, allows theof this colon ; definition to be found in the dictionary, sets interpret state and compiles ; EXIT (or a system dependent word which performs an equivalent function). ; sys is balanced with its corresponding : . ; See: EXIT : "stack, return" "9.4 Compilation" semih data ecodeh,immed+1 text '; ' semi data docol data compile,exit ; compile EXIT data lates_,fetch,hideme ; un-hide the word ; flag to indicate no unbalanced errors detected... data lit0 ; check IF...THEN reference counts, error if count>0... data lit,ifcnt,fetch,zbrnch,doerr data isserr data toterm,iferr ; check DO...LOOP reference counts, error if count>0... doerr data lit,docnt,fetch,zbrnch,caserr data isserr data toterm,doertx ; check CASE...ENDCASE reference counts, error if count>0 caserr data lit,cascnt,fetch,zbrnch,oferr data isserr data toterm,castxt ; check OF...ENDOF reference counts, error if count>0 oferr data lit,ofcnt,fetch,zbrnch,begerr data isserr data toterm,oftxt ; check BEGIN/UNTIL/REPEAT reference counts, error if count>0 begerr data lit,begcnt,fetch,zbrnch,allfin data isserr data toterm,begtxt ; abort if one of the above error conditions exist allfin data zbrnch,semi2 ; test unbalanced error flag data ab0rt ; issue warning if this word is a re-definition... semi2 data lit,temp,fetch,zbrnch,semi3 ; skip if not a redefinition data rdferr ; else issue warning if enabled ; end of colon definition, reset compile state... semi3 data lbrack ; go into interpret mode data exit isserr data docol,cr,error,toterm,intxt,colnam,unbal data plus1 ; set unbalanced error detect to non-zero value data exit ;] ; HIDDEN ( dictionary_address -- ) ; toggles the hidden attribute on the dictionary entry ; normally you would hide a word after defining it with: LATEST @ HIDDEN hidh data semih,6 text 'HIDDEN' hideme data $+2 bl @bank1 data _hide ; IMMEDIATE -- 79 ; Marks the most recently created dictionary entry as a word which will be ; executed when encountered during compilation rather than compiled. immh data hidh,9 text 'IMMEDIATE ' imm data $+2 bl @bank1 data _imm ; ['] -- addr C,I,M,83 "bracket-tick" ; -- (compiling) ; Used in the form: ; [']; Compiles the compilation address addr of as a literal. ; When the colon definition is later executed addr is left on the stack. ; An error condition exists ifis not found in the currently active ; search order. See: LITERAL tickh data immh,immed+3 text '[''] ' tick data docol,getword,litral,exit ; ' -- addr M,83 "tick" ; Used in the form: ; '; addr is the compilation address of . ; An error condition exists ifis not found in the currently active ; search order. tick2h data tickh,1 text ''' ' tick2 data docol,getword,exit ; COMPILE -- C,83 ; Typically used in the form: ; :... COMPILE ... ; ; When is executed, the compilation address compiled for ; compiled and not executed. ;is is typically immediate and ; See: "compilation" compih data tick2h,7 text 'COMPILE ' compile data $+2 ; note: the following line of code MUST be executed from bank 0. ; It cannot execute in bank 1 because all the Forth CFAs are in bank 0. mov *pc+,r1 ; get cfa of next word in thread bl @bank1 ; do the rest in bank 1 data _compilis typically not immediate.