X-Git-Url: https://thelambdalab.xyz/gitweb/index.cgi?p=forth.jl.git;a=blobdiff_plain;f=src%2Flib.4th;h=955cadfe236e34a1c286d4e98c9f5659b5245676;hp=22b7884d02899004b9ed4883984dfd5989df9f8c;hb=d2b2b3e5b33f882c18c9e7cf8c6623f4e863c2dd;hpb=2a0eccda84f6f59b9f88b9d4901f17c6c7b7814a diff --git a/src/lib.4th b/src/lib.4th index 22b7884..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 / ; @@ -8,7 +15,16 @@ : 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 @ - ; @@ -17,17 +33,10 @@ : 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 ; @@ -171,17 +180,47 @@ [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 -- ) @@ -392,7 +426,7 @@ 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 ) @@ -419,52 +453,45 @@ ; : ." 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 ) ; -: ALLOT ( n -- addr ) - HERE @ SWAP ( here n ) +: 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 ) - WORD CREATE ( 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 CREATE ( make the dictionary entry (the name follows VALUE) ) + WORD HEADER ( make the dictionary entry (the name follows VALUE) ) DOCOL , ( append DOCOL ) ['] LIT , ( append the codeword LIT ) , ( append the initial value ) @@ -500,6 +527,17 @@ 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 ------------------------------------------------------ ) @@ -513,7 +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 -- ) @@ -544,6 +588,7 @@ CR ; + ( FORGET ---------------------------------------------------------------------- ) : FORGET @@ -556,34 +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 ------------------------------------------------------------------ ) @@ -622,9 +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 + ( [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 ) @@ -640,11 +681,11 @@ . ( 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 ) + [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 @@ -661,7 +702,7 @@ ." ) " ENDOF ['] ['] OF ( is it ['] ? ) - [ CHAR ' ] LITERAL EMIT SPACE + ." ['] " 1+ DUP @ ( get the next codeword ) CFA> ( and force it to be printed as a dictionary entry ) ID. SPACE @@ -685,14 +726,13 @@ 1+ ( end start+1 ) REPEAT - ';' EMIT CR + [CHAR] ; EMIT CR 2DROP ( restore stack ) ; -( WELCOME MESSAGE ------------------------------------------------------------- ) - -CR CR ." --- TimForth initialized --- " - +( MEMORY ------------------------------------------------------------------ ) +: UNUSED ( -- cells ) + MEMSIZE HERE @ - ;