X-Git-Url: https://thelambdalab.xyz/gitweb/index.cgi?p=forth.jl.git;a=blobdiff_plain;f=src%2Flib.4th;h=955cadfe236e34a1c286d4e98c9f5659b5245676;hp=d806cb8753be907bea4bbad35ada96f26dfa123e;hb=d2b2b3e5b33f882c18c9e7cf8c6623f4e863c2dd;hpb=921518e9d5a109a02f02a70b8a8d117707b1df97 diff --git a/src/lib.4th b/src/lib.4th index d806cb8..955cadf 100644 --- a/src/lib.4th +++ b/src/lib.4th @@ -1,3 +1,10 @@ +: \ IMMEDIATE + KEY + 10 = 0BRANCH [ -5 , ] +; \ We can now comment! + +\ BASIC DEFINITIONS ---------------------------------------------------------------------- + : / /MOD SWAP DROP ; : MOD /MOD DROP ; : */ -ROT * SWAP / ; @@ -8,26 +15,28 @@ : 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 @ - ; : '\n' 10 ; : BL 32 ; -: LITERAL IMMEDIATE ' LIT , , ; +: 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 ; +: [CHAR] IMMEDIATE + CHAR + ['] LIT , , +; : CR '\n' emit ; : SPACE BL emit ; @@ -51,7 +60,7 @@ \ CONTROL STRUCTURES ---------------------------------------------------------------------- : IF IMMEDIATE - ' 0BRANCH , \ compile 0BRANCH + ['] 0BRANCH , \ compile 0BRANCH HERE @ \ save location of the offset on the stack 0 , \ compile a dummy offset ; @@ -63,7 +72,7 @@ ; : ELSE IMMEDIATE - ' BRANCH , \ definite branch to just over the false-part + ['] BRANCH , \ definite branch to just over the false-part HERE @ \ save location of the offset on the stack 0 , \ compile a dummy offset SWAP \ now back-fill the original (IF) offset @@ -77,25 +86,25 @@ ; : UNTIL IMMEDIATE - ' 0BRANCH , \ compile 0BRANCH + ['] 0BRANCH , \ compile 0BRANCH HERE @ - \ calculate the offset from the address saved on the stack , \ compile the offset here ; : AGAIN IMMEDIATE - ' BRANCH , \ compile BRANCH + ['] BRANCH , \ compile BRANCH HERE @ - \ calculate the offset back , \ compile the offset here ; : WHILE IMMEDIATE - ' 0BRANCH , \ compile 0BRANCH + ['] 0BRANCH , \ compile 0BRANCH HERE @ \ save location of the offset2 on the stack 0 , \ compile a dummy offset2 ; : REPEAT IMMEDIATE - ' BRANCH , \ compile BRANCH + ['] BRANCH , \ compile BRANCH SWAP \ get the original offset (from BEGIN) HERE @ - , \ and compile it after BRANCH DUP @@ -104,21 +113,21 @@ ; : UNLESS IMMEDIATE - ' NOT , \ compile NOT (to reverse the test) + ['] NOT , \ compile NOT (to reverse the test) [COMPILE] IF \ continue by calling the normal IF ; : DO IMMEDIATE - ' LIT , -1 , [COMPILE] IF - ' >R , ' >R , - ' LIT , HERE @ 0 , ' >R , + ['] LIT , -1 , [COMPILE] IF + ['] >R , ['] >R , + ['] LIT , HERE @ 0 , ['] >R , HERE @ ; : ?DO IMMEDIATE - ' 2DUP , ' - , [COMPILE] IF - ' >R , ' >R , - ' LIT , HERE @ 0 , ' >R , + ['] 2DUP , ['] - , [COMPILE] IF + ['] >R , ['] >R , + ['] LIT , HERE @ 0 , ['] >R , HERE @ ; @@ -127,61 +136,91 @@ : J RSP@ 6 - @ ; : ?LEAVE IMMEDIATE - ' 0BRANCH , 13 , - ' R> , ' RDROP , ' RDROP , - ' LIT , HERE @ 7 + , ' DUP , ' -ROT , ' - , ' SWAP , ' ! , - ' BRANCH , + ['] 0BRANCH , 13 , + ['] R> , ['] RDROP , ['] RDROP , + ['] LIT , HERE @ 7 + , ['] DUP , ['] -ROT , ['] - , ['] SWAP , ['] ! , + ['] BRANCH , 0 , ; : LEAVE IMMEDIATE - ' LIT , -1 , + ['] LIT , -1 , [COMPILE] ?LEAVE ; : +LOOP IMMEDIATE - ' DUP , \ Store copy of increment + ['] DUP , \ Store copy of increment - ' R> , ' SWAP , ' R> , ' SWAP , ' R> , ' SWAP , ' + , ' 2DUP , ' - , - ' SWAP , ' >R , ' SWAP , ' >R , ' SWAP , ' >R , + ['] R> , ['] SWAP , ['] R> , ['] SWAP , ['] R> , ['] SWAP , ['] + , ['] 2DUP , ['] - , + ['] SWAP , ['] >R , ['] SWAP , ['] >R , ['] SWAP , ['] >R , \ Condition differently depending on sign of increment - ' SWAP , ' 0>= , [COMPILE] IF - ' 0<= , + ['] SWAP , ['] 0>= , [COMPILE] IF + ['] 0<= , [COMPILE] ELSE - ' 0> , + ['] 0> , [COMPILE] THEN \ Branch back to begining of loop kernel - ' 0BRANCH , HERE @ - , + ['] 0BRANCH , HERE @ - , \ Clean up - ' RDROP , ' RDROP , ' RDROP , + ['] RDROP , ['] RDROP , ['] RDROP , \ Record address of loop end for any LEAVEs to use HERE @ SWAP ! [COMPILE] ELSE - ' 2DROP , \ Clean up if loop was entirely skipped (?DO) + ['] 2DROP , \ Clean up if loop was entirely skipped (?DO) [COMPILE] THEN ; : LOOP IMMEDIATE - ' LIT , 1 , + ['] LIT , 1 , [COMPILE] +LOOP ; + +\ CASE ------------------------------------------------------------------------ + +: CASE IMMEDIATE + 0 \ push 0 to mark the bottom of the stack +; + +: OF IMMEDIATE + ['] OVER , \ compile OVER + ['] = , \ compile = + [COMPILE] IF \ compile IF + ['] DROP , \ compile DROP +; + +: ENDOF IMMEDIATE + [COMPILE] ELSE \ ENDOF is the same as ELSE +; + +: ENDCASE IMMEDIATE + ['] DROP , \ compile DROP + + \ keep compiling THEN until we get to our zero marker + BEGIN + ?DUP + WHILE + [COMPILE] THEN + REPEAT +; + + \ COMMENTS ---------------------------------------------------------------------- : ( IMMEDIATE 1 \ allowed nested parens by keeping track of depth BEGIN KEY \ read next character - DUP '(' = IF \ open paren? + 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 @@ -253,10 +292,10 @@ ( 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 @@ -309,7 +348,7 @@ SWAP ( u flag ) IF ( was it negative? print the - character ) - '-' EMIT + [CHAR] - EMIT THEN U. @@ -318,7 +357,7 @@ : . 0 .R SPACE ; : .S ( -- ) - '<' EMIT DEPTH U. '>' EMIT SPACE + [CHAR] < EMIT DEPTH U. [CHAR] > EMIT SPACE PSP0 @ 1+ BEGIN DUP PSP@ 2 - <= @@ -353,11 +392,6 @@ ( 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 -- ) @@ -386,13 +420,13 @@ : S" IMMEDIATE ( -- addr len ) STATE @ IF ( compiling? ) - ' LITSTRING , ( compile LITSTRING ) + ['] LITSTRING , ( compile LITSTRING ) 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 '"' <> + DUP [CHAR] " <> WHILE C, ( copy character ) REPEAT @@ -406,7 +440,7 @@ KEY DROP BEGIN KEY - DUP '"' <> + DUP [CHAR] " <> WHILE OVER C! ( save next character ) 1+ ( increment address ) @@ -419,33 +453,90 @@ ; : ." 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. ) + ['] TELL , ( compile the final TELL ) ; +: .( + KEY DROP + BEGIN + KEY + DUP [CHAR] ) = IF + DROP ( drop the double quote character ) + EXIT ( return from this function ) + THEN + EMIT + AGAIN +; + + ( CONSTANTS AND VARIABLES ------------------------------------------------------ ) : CONSTANT - WORD ( get the name (the name follows CONSTANT) ) - CREATE ( make the dictionary entry ) + 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 ) + ['] LIT , ( append the codeword LIT ) + , ( append the value on the top of the stack ) + ['] EXIT , ( append the codeword EXIT ) +; + +: ALLOT ( n -- ) + HERE +! ( adds n to HERE, after this the old value of HERE is still on the stack ) +; + +: VARIABLE + CREATE + 1 CELLS ALLOT ( allocate 1 cell of memory, push the pointer to this memory ) +; + + +: 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 ) +; + +: 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 ) + STATE @ IF ( compiling? ) + ['] LIT , ( compile LIT ) + , ( compile the address of the value ) + ['] ! , ( compile ! ) + ELSE ( immediate mode ) + ! ( update it straightaway ) + THEN +; + +( 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 ) + STATE @ IF ( compiling? ) + ['] LIT , ( compile LIT ) + , ( compile the address of the value ) + ['] +! , ( compile +! ) + ELSE ( immediate mode ) + +! ( update it straightaway ) + 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 ------------------------------------------------------ ) @@ -460,7 +551,13 @@ WHILE SWAP 1+ ( addr len -- len addr+1 ) DUP @ ( len addr -- len addr char | get the next character) - EMIT ( len addr char -- len addr | and print it) + DUP 32 >= OVER 127 <= AND IF + EMIT ( len addr char -- len addr | and print it) + ELSE + BASE @ SWAP HEX + ." \x" 0 .R + BASE ! + THEN SWAP 1- ( len addr -- addr len-1 | subtract one from length ) REPEAT 2DROP ( len addr -- ) @@ -491,6 +588,7 @@ CR ; + ( FORGET ---------------------------------------------------------------------- ) : FORGET @@ -503,34 +601,6 @@ \ TODO! -( CASE ------------------------------------------------------------------------ ) - -: CASE IMMEDIATE - 0 ( push 0 to mark the bottom of the stack ) -; - -: OF IMMEDIATE - ' OVER , ( compile OVER ) - ' = , ( compile = ) - [COMPILE] IF ( compile IF ) - ' DROP , ( compile DROP ) -; - -: ENDOF IMMEDIATE - [COMPILE] ELSE ( ENDOF is the same as ELSE ) -; - -: ENDCASE IMMEDIATE - ' DROP , ( compile DROP ) - - ( keep compiling THEN until we get to our zero marker ) - BEGIN - ?DUP - WHILE - [COMPILE] THEN - REPEAT -; - ( DECOMPILER ------------------------------------------------------------------ ) @@ -569,10 +639,33 @@ DROP ( at this point, the stack is: start-of-word end-of-word ) SWAP ( end-of-word start-of-word ) + DUP >CFA @ CASE + DOCOL OF + \ Colon definition + [CHAR] : EMIT SPACE DUP ID. SPACE + DUP ?IMMEDIATE IF ." IMMEDIATE " THEN CR + ENDOF + DOVAR OF + \ Variable definition + ." Variable " DUP ID. CR + 2DROP EXIT + ENDOF + DOCON OF + \ Constant definition + ." Constant " DUP ID. CR + 2DROP EXIT + ENDOF + + \ Unknown codeword + ." Primitive or word with unrecognized codeword." CR + DROP 2DROP EXIT + ENDCASE + ( begin the definition with : NAME [IMMEDIATE] ) - ':' EMIT SPACE DUP ID. SPACE - DUP ?IMMEDIATE IF ." IMMEDIATE " THEN - CR 8 SPACES + ( [CHAR] : 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 ) @@ -580,43 +673,41 @@ BEGIN ( end start ) 2DUP > WHILE - DUP @ CFA> ID. SPACE - 1+ -( DUP @ ( end start codeword ) + DUP @ ( end start codeword ) CASE - ' LIT OF ( is it LIT ? ) + ['] LIT OF ( is it LIT ? ) 1+ DUP @ ( get next word which is the integer constant ) . ( and print it ) ENDOF - ' LITSTRING OF ( is it LITSTRING ? ) - [ CHAR S ] LITERAL EMIT '"' EMIT SPACE ( print S" ) + ['] LITSTRING OF ( is it LITSTRING ? ) + [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 ) + [CHAR] " EMIT SPACE ( finish the string with a final quote ) + ( end start+1+len, aligned ) - 1- ( because we're about to add 1 below ) + 1- ( because we're about to add 4 below ) ENDOF - ' 0BRANCH OF ( is it 0BRANCH ? ) + ['] 0BRANCH OF ( is it 0BRANCH ? ) ." 0BRANCH ( " 1+ DUP @ ( print the offset ) . ." ) " ENDOF - ' BRANCH OF ( is it BRANCH ? ) + ['] BRANCH OF ( is it BRANCH ? ) ." BRANCH ( " 1+ DUP @ ( print the offset ) . ." ) " ENDOF - ' ' OF ( is it ' (TICK) ? ) - [ CHAR ' ] LITERAL EMIT SPACE + ['] ['] OF ( is it ['] ? ) + ." ['] " 1+ DUP @ ( get the next codeword ) CFA> ( and force it to be printed as a dictionary entry ) ID. SPACE ENDOF - ' EXIT OF ( is it EXIT? ) + ['] EXIT OF ( is it EXIT? ) ( We expect the last word to be EXIT, and if it is then we don't print it because EXIT is normally implied by ;. EXIT can also appear in the middle of words, and then it needs to be printed. ) @@ -633,17 +724,15 @@ ENDCASE 1+ ( end start+1 ) -) REPEAT - ';' EMIT CR + [CHAR] ; EMIT CR 2DROP ( restore stack ) ; -( WELCOME MESSAGE ------------------------------------------------------------- ) - -CR CR ." --- TimForth initialized --- " - +( MEMORY ------------------------------------------------------------------ ) +: UNUSED ( -- cells ) + MEMSIZE HERE @ - ;