X-Git-Url: https://thelambdalab.xyz/gitweb/index.cgi?a=blobdiff_plain;f=src%2Flib.4th;h=8da2fb1c65983365fcb421d5886c72974816c45f;hb=b18e42773e45b9d4819cf0e2d2c5965bd34dcb4f;hp=6b2d8aef17be80a6634fe2b2c201b9bc3bf8a012;hpb=bb362c83787c336261014bdb16f5cf0841c8b506;p=forth.jl.git diff --git a/src/lib.4th b/src/lib.4th index 6b2d8ae..8da2fb1 100644 --- a/src/lib.4th +++ b/src/lib.4th @@ -1,3 +1,9 @@ +: \ IMMEDIATE + #TIB @ >IN ! +; \ We can now comment! + +\ BASIC DEFINITIONS ---------------------------------------------------------------------- + : / /MOD SWAP DROP ; : MOD /MOD DROP ; : */ -ROT * SWAP / ; @@ -8,34 +14,38 @@ : FALSE 0 ; : NOT 0= ; -: CELLS ; \ Allow for slightly more portable code +\ Translate a number of cells into memory units +\ (in our case 1 cell = 1 memory unit) +: CELLS ; + +\ Since the smallest unit of memory in our system is 64 bits and since strings +\ are stored as arrays of 64 bit integers, the character store/fetch words are +\ just aliases of the standard store/fetch words. +: C! ! ; +: C@ @ ; +: C, , ; -: DEPTH PSP@ PSP0 @ - ; +: DEPTH PSP@ PSP0 - ; : '\n' 10 ; : BL 32 ; : LITERAL IMMEDIATE ['] LIT , , ; -: ':' [ CHAR : ] LITERAL ; -: ';' [ CHAR ; ] LITERAL ; -: '(' [ CHAR ( ] LITERAL ; -: ')' [ CHAR ) ] LITERAL ; -: '<' [ CHAR < ] LITERAL ; -: '>' [ CHAR > ] LITERAL ; -: '"' [ CHAR " ] LITERAL ; -: 'A' [ CHAR A ] LITERAL ; -: '0' [ CHAR 0 ] LITERAL ; -: '-' [ CHAR - ] LITERAL ; -: '.' [ CHAR . ] LITERAL ; +: ' BL WORD FIND DROP ; + +: CHAR BL WORD 1+ @ ; +: [CHAR] IMMEDIATE + CHAR + ['] LIT , , +; : CR '\n' emit ; : SPACE BL emit ; : [COMPILE] IMMEDIATE - WORD \ get the next word - FIND \ find it in the dictionary - >CFA \ get its codeword + BL WORD \ get the next word + FIND DROP \ find it in the dictionary , \ and compile that ; @@ -45,61 +55,58 @@ , \ compile it ; -: DEBUGON TRUE DEBUG ! ; -: DEBUGOFF FALSE DEBUG ! ; - \ CONTROL STRUCTURES ---------------------------------------------------------------------- : IF IMMEDIATE ['] 0BRANCH , \ compile 0BRANCH - HERE @ \ save location of the offset on the stack + HERE \ save location of the offset on the stack 0 , \ compile a dummy offset ; : THEN IMMEDIATE DUP - HERE @ SWAP - \ calculate the offset from the address saved on the stack + HERE SWAP - \ calculate the offset from the address saved on the stack SWAP ! \ store the offset in the back-filled location ; : ELSE IMMEDIATE ['] BRANCH , \ definite branch to just over the false-part - HERE @ \ save location of the offset on the stack + HERE \ save location of the offset on the stack 0 , \ compile a dummy offset SWAP \ now back-fill the original (IF) offset DUP \ same as for THEN word above - HERE @ SWAP - + HERE SWAP - SWAP ! ; : BEGIN IMMEDIATE - HERE @ \ save location on the stack + HERE \ save location on the stack ; : UNTIL IMMEDIATE ['] 0BRANCH , \ compile 0BRANCH - HERE @ - \ calculate the offset from the address saved on the stack + HERE - \ calculate the offset from the address saved on the stack , \ compile the offset here ; : AGAIN IMMEDIATE ['] BRANCH , \ compile BRANCH - HERE @ - \ calculate the offset back + HERE - \ calculate the offset back , \ compile the offset here ; : WHILE IMMEDIATE ['] 0BRANCH , \ compile 0BRANCH - HERE @ \ save location of the offset2 on the stack + HERE \ save location of the offset2 on the stack 0 , \ compile a dummy offset2 ; : REPEAT IMMEDIATE ['] BRANCH , \ compile BRANCH SWAP \ get the original offset (from BEGIN) - HERE @ - , \ and compile it after BRANCH + HERE - , \ and compile it after BRANCH DUP - HERE @ SWAP - \ calculate the offset2 + HERE SWAP - \ calculate the offset2 SWAP ! \ and back-fill it in the original location ; @@ -111,15 +118,15 @@ : DO IMMEDIATE ['] LIT , -1 , [COMPILE] IF ['] >R , ['] >R , - ['] LIT , HERE @ 0 , ['] >R , - HERE @ + ['] LIT , HERE 0 , ['] >R , + HERE ; : ?DO IMMEDIATE ['] 2DUP , ['] - , [COMPILE] IF ['] >R , ['] >R , - ['] LIT , HERE @ 0 , ['] >R , - HERE @ + ['] LIT , HERE 0 , ['] >R , + HERE ; : I RSP@ 3 - @ ; @@ -129,7 +136,7 @@ : ?LEAVE IMMEDIATE ['] 0BRANCH , 13 , ['] R> , ['] RDROP , ['] RDROP , - ['] LIT , HERE @ 7 + , ['] DUP , ['] -ROT , ['] - , ['] SWAP , ['] ! , + ['] LIT , HERE 7 + , ['] DUP , ['] -ROT , ['] - , ['] SWAP , ['] ! , ['] BRANCH , 0 , ; @@ -140,6 +147,7 @@ ; : +LOOP IMMEDIATE + ['] DUP , \ Store copy of increment ['] R> , ['] SWAP , ['] R> , ['] SWAP , ['] R> , ['] SWAP , ['] + , ['] 2DUP , ['] - , @@ -153,13 +161,13 @@ [COMPILE] THEN \ Branch back to begining of loop kernel - ['] 0BRANCH , HERE @ - , + ['] 0BRANCH , HERE - , \ Clean up ['] RDROP , ['] RDROP , ['] RDROP , \ Record address of loop end for any LEAVEs to use - HERE @ SWAP ! + HERE SWAP ! [COMPILE] ELSE ['] 2DROP , \ Clean up if loop was entirely skipped (?DO) @@ -206,12 +214,16 @@ : ( IMMEDIATE 1 \ allowed nested parens by keeping track of depth BEGIN - KEY \ read next character - DUP '(' = IF \ open paren? + >IN @ #TIB @ >= IF \ End of TIB? + QUERY \ Get next line + THEN + + TIB >IN @ + @ 1 >IN +! + DUP [CHAR] ( = IF \ open paren? DROP \ drop the open paren 1+ \ depth increases ELSE - ')' = IF \ close paren? + [CHAR] ) = IF \ close paren? 1- \ depth decreases THEN THEN @@ -283,10 +295,10 @@ ( print the remainder ) DUP 10 < IF - '0' ( decimal digits 0..9 ) + [CHAR] 0 ( decimal digits 0..9 ) ELSE 10 - ( hex and beyond digits A..Z ) - 'A' + [CHAR] A THEN + EMIT @@ -339,7 +351,7 @@ SWAP ( u flag ) IF ( was it negative? print the - character ) - '-' EMIT + [CHAR] - EMIT THEN U. @@ -348,8 +360,8 @@ : . 0 .R SPACE ; : .S ( -- ) - '<' EMIT DEPTH U. '>' EMIT SPACE - PSP0 @ 1+ + [CHAR] < EMIT DEPTH U. [CHAR] > EMIT SPACE + PSP0 1+ BEGIN DUP PSP@ 2 - <= WHILE @@ -383,11 +395,6 @@ ( STRINGS ---------------------------------------------------------------------- ) -( Since the smallest unit of memory in our system is 64 bits and since strings - are stored as arrays of 64 bit integers, the character store/fetch words are - just aliases of the standard store/fetch words. ) -: C! ! ; -: C@ @ ; ( Block copy, however, is important and novel: ) : CMOVE ( src dest length -- ) @@ -410,102 +417,106 @@ ( C, appends a byte to the current compiled word. ) : C, - HERE @ C! - 1 HERE +! + HERE C! + 1 H +! ; : S" IMMEDIATE ( -- addr len ) STATE @ IF ( compiling? ) ['] LITSTRING , ( compile LITSTRING ) - HERE @ ( save the address of the length word on the stack ) + HERE ( save the address of the length word on the stack ) 0 , ( dummy length - we don't know what it is yet ) - KEY DROP + BEGIN - KEY ( get next character of the string ) - DUP '"' <> + >IN @ #TIB @ >= IF \ End of TIB? + QUERY \ Get next line + THEN + + TIB >IN @ + @ 1 >IN +! \ Get char from TIB + + DUP [CHAR] " <> WHILE C, ( copy character ) REPEAT DROP ( drop the double quote character at the end ) DUP ( get the saved address of the length word ) - HERE @ SWAP - ( calculate the length ) + HERE SWAP - ( calculate the length ) 1- ( subtract 1 (because we measured from the start of the length word) ) SWAP ! ( and back-fill the length location ) ELSE ( immediate mode ) - HERE @ ( get the start address of the temporary space ) - KEY DROP + HERE ( get the start address of the temporary space ) + BEGIN - KEY - DUP '"' <> + >IN @ #TIB @ >= IF \ End of TIB? + QUERY \ Get next line + THEN + + TIB >IN @ + @ 1 >IN +! \ Get char from TIB + + DUP [CHAR] " <> WHILE OVER C! ( save next character ) 1+ ( increment address ) REPEAT DROP ( drop the final " character ) - HERE @ - ( calculate the length ) - HERE @ ( push the start address ) + HERE - ( calculate the length ) + HERE ( push the start address ) SWAP ( addr len ) THEN ; : ." IMMEDIATE ( -- ) - STATE @ IF ( compiling? ) - [COMPILE] S" ( read the string, and compile LITSTRING, etc. ) - ['] TELL , ( compile the final TELL ) - ELSE - ( In immediate mode, just read characters and print them until we get - to the ending double quote. ) - KEY DROP - BEGIN - KEY - DUP '"' = IF - DROP ( drop the double quote character ) - EXIT ( return from this function ) - THEN - EMIT - AGAIN - THEN + [COMPILE] S" ( read the string, and compile LITSTRING, etc. ) + ['] TYPE , ( compile the final TYPE ) ; +: .( + BEGIN + >IN @ #TIB @ >= IF \ End of TIB? + QUERY \ Get next line + THEN + + TIB >IN @ + @ 1 >IN +! \ Get char from TIB + + DUP [CHAR] ) = IF + DROP ( drop the double quote character ) + EXIT ( return from this function ) + THEN + EMIT + AGAIN +; + +( Converts address of counted string into address of + start of string and length of string. ) +: COUNT ( addr1 -- addr2 n ) + DUP 1+ SWAP @ ; + ( CONSTANTS AND VARIABLES ------------------------------------------------------ ) : CONSTANT - WORD HEADER ( make dictionary entry (the name follows CONSTANT) ) - DOCOL , ( append DOCOL (the codeword field of this word) ) - ['] LIT , ( append the codeword LIT ) - , ( append the value on the top of the stack ) - ['] EXIT , ( append the codeword EXIT ) + CREATE , +DOES> @ ; -: ALLOT ( n -- addr ) - HERE @ SWAP ( here n ) - HERE +! ( adds n to HERE, after this the old value of HERE is still on the stack ) +: ALLOT ( n -- ) + H +! ( adds n to H, after this the old value of H is still on the stack ) ; : VARIABLE + CREATE 1 CELLS ALLOT ( allocate 1 cell of memory, push the pointer to this memory ) - WORD HEADER ( make the dictionary entry (the name follows VARIABLE) ) - DOCOL , ( append DOCOL (the codeword field of this word) ) - ['] LIT , ( append the codeword LIT ) - , ( append the pointer to the new memory ) - ['] EXIT , ( append the codeword EXIT ) ; - : VALUE ( n -- ) - WORD HEADER ( make the dictionary entry (the name follows VALUE) ) - DOCOL , ( append DOCOL ) - ['] LIT , ( append the codeword LIT ) - , ( append the initial value ) - ['] EXIT , ( append the codeword EXIT ) + CREATE , +DOES> @ ; : TO IMMEDIATE ( n -- ) - WORD ( get the name of the value ) - FIND ( look it up in the dictionary ) - >DFA ( get a pointer to the first data field (the 'LIT') ) - 1+ ( increment to point at the value ) + BL WORD ( get the name of the value ) + FIND DROP ( look it up in the dictionary ) + >BODY ( get a pointer to the first data field (the 'LIT') ) STATE @ IF ( compiling? ) ['] LIT , ( compile LIT ) , ( compile the address of the value ) @@ -517,10 +528,9 @@ ( x +TO VAL adds x to VAL ) : +TO IMMEDIATE - WORD ( get the name of the value ) - FIND ( look it up in the dictionary ) - >DFA ( get a pointer to the first data field (the 'LIT') ) - 1+ ( increment to point at the value ) + BL WORD ( get the name of the value ) + FIND DROP ( look it up in the dictionary ) + >BODY ( get a pointer to the first data field (the 'LIT') ) STATE @ IF ( compiling? ) ['] LIT , ( compile LIT ) , ( compile the address of the value ) @@ -530,11 +540,21 @@ THEN ; +( Fill u ints, starting at a, with the value b ) +: FILL ( a u b -- ) + -ROT OVER + SWAP ?DO + DUP I ! + LOOP + DROP +; + +: ERASE ( a u -- ) + 0 FILL +; ( PRINTING THE DICTIONARY ------------------------------------------------------ ) -: ID. - 1+ ( skip over the link pointer ) +: .NAME DUP @ ( get the flags/length byte ) F_LENMASK AND ( mask out the flags - just want the length ) @@ -567,12 +587,13 @@ ; : WORDS + CR LATEST @ ( start at LATEST dictionary entry ) BEGIN ?DUP ( while link pointer is not null ) WHILE DUP ?HIDDEN NOT IF ( ignore hidden words ) - DUP ID. ( but if not hidden, print the word ) + DUP 1+ .NAME ( but if not hidden, print the word ) SPACE THEN @ ( dereference the link pointer - go to previous word ) @@ -580,15 +601,6 @@ CR ; - -( FORGET ---------------------------------------------------------------------- ) - -: FORGET - WORD FIND ( find the word, gets the dictionary entry address ) - DUP @ LATEST ! ( set LATEST to point to the previous word ) - HERE ! ( and store HERE with the dictionary address ) -; - ( DUMP ------------------------------------------------------------------------ ) \ TODO! @@ -596,28 +608,30 @@ ( DECOMPILER ------------------------------------------------------------------ ) -: CFA> - LATEST @ ( start at LATEST dictionary entry ) +: >NAME BEGIN - ?DUP ( while link pointer is not null ) - WHILE - 2DUP SWAP ( cfa curr curr cfa ) - < IF ( current dictionary entry < cfa? ) - NIP ( leave curr dictionary entry on the stack ) - EXIT - THEN - @ ( follow link pointer back ) - REPEAT - DROP ( restore stack ) - 0 ( sorry, nothing found ) + 1- DUP @ + NFA_MARK AND + NFA_MARK = UNTIL ; +: >LFA >NAME 1- ; + : SEE - WORD FIND ( find the dictionary entry to decompile ) + BL WORD FIND ( find the dictionary entry to decompile ) + + CR + + 0= IF + ." Word '" COUNT TYPE ." ' not found in dictionary." + EXIT + THEN + + >LFA ( Now we search again, looking for the next word in the dictionary. This gives us the length of the word that we will be decompiling. (Well, mostly it does). ) - HERE @ ( address of the end of the last compiled word ) + HERE ( address of the end of the last compiled word ) LATEST @ ( word last curr ) BEGIN 2 PICK ( word last curr word ) @@ -634,17 +648,17 @@ DUP >CFA @ CASE DOCOL OF \ Colon definition - ':' EMIT SPACE DUP ID. SPACE + [CHAR] : EMIT SPACE DUP 1+ .NAME SPACE DUP ?IMMEDIATE IF ." IMMEDIATE " THEN CR ENDOF DOVAR OF \ Variable definition - ." Variable " DUP ID. CR + ." Variable " DUP 1+ .NAME CR 2DROP EXIT ENDOF DOCON OF \ Constant definition - ." Constant " DUP ID. CR + ." Constant " DUP 1+ .NAME CR 2DROP EXIT ENDOF @@ -653,13 +667,9 @@ DROP 2DROP EXIT ENDCASE - ( begin the definition with : NAME [IMMEDIATE] ) - ( ':' EMIT SPACE DUP ID. SPACE - DUP ?IMMEDIATE IF ." IMMEDIATE " THEN CR 4 ) - 4 SPACES - >DFA ( get the data address, ie. points after DOCOL | end-of-word start-of-data ) + >CFA >BODY ( get the data address, ie. points after DOCOL | end-of-word start-of-data ) ( now we start decompiling until we hit the end of the word ) BEGIN ( end start ) @@ -673,11 +683,11 @@ . ( and print it ) ENDOF ['] LITSTRING OF ( is it LITSTRING ? ) - [ CHAR S ] LITERAL EMIT '"' EMIT SPACE ( print S" ) + [CHAR] S EMIT [CHAR] " EMIT SPACE ( print S" ) 1+ DUP @ ( get the length word ) SWAP 1+ SWAP ( end start+1 length ) - 2DUP TELL ( print the string ) - '"' EMIT SPACE ( finish the string with a final quote ) + 2DUP TYPE ( print the string ) + [CHAR] " EMIT SPACE ( finish the string with a final quote ) + ( end start+1+len, aligned ) 1- ( because we're about to add 4 below ) ENDOF @@ -696,8 +706,8 @@ ['] ['] OF ( is it ['] ? ) ." ['] " 1+ DUP @ ( get the next codeword ) - CFA> ( and force it to be printed as a dictionary entry ) - ID. SPACE + >NAME ( and force it to be printed as a dictionary entry ) + .NAME SPACE ENDOF ['] EXIT OF ( is it EXIT? ) ( We expect the last word to be EXIT, and if it is then we don't print it @@ -711,15 +721,33 @@ ENDOF ( default case: ) DUP ( in the default case we always need to DUP before using ) - CFA> ( look up the codeword to get the dictionary entry ) - ID. SPACE ( and print it ) + >NAME ( look up the codeword to get the dictionary entry ) + .NAME SPACE ( and print it ) ENDCASE 1+ ( end start+1 ) REPEAT - ';' EMIT CR + [CHAR] ; EMIT CR 2DROP ( restore stack ) ; + +( FORGET and HIDE ------------------------------------------------------------ ) + +: FORGET + BL WORD FIND >LFA ( find the word, gets the dictionary entry address ) + DUP @ LATEST ! ( set LATEST to point to the previous word ) + H ! ( and store H with the dictionary address ) +; + +: HIDE + BL WORD FIND DROP >NAME + DUP @ F_HIDDEN OR SWAP ! +; + +( MEMORY ------------------------------------------------------------------ ) + +: UNUSED ( -- cells ) + MEMSIZE HERE - ;