X-Git-Url: https://thelambdalab.xyz/gitweb/index.cgi?p=forth.jl.git;a=blobdiff_plain;f=src%2Flib.4th;h=87e1839de0ff2e29504aa39f4ef9ffff348e6793;hp=5ff3e22ad9fe5ff238617c8d20b9a89084959791;hb=acee38d57f2ee38911c4ed46bab9b7a864686c24;hpb=26f24e50ac8fe3beeaf465378ce7ee989e101b61 diff --git a/src/lib.4th b/src/lib.4th index 5ff3e22..87e1839 100644 --- a/src/lib.4th +++ b/src/lib.4th @@ -1,440 +1,45 @@ -: / /MOD SWAP DROP ; -: MOD /MOD DROP ; -: */ -ROT * SWAP / ; - -: NEGATE 0 SWAP - ; - -: TRUE -1 ; -: FALSE 0 ; -: NOT 0= ; - -: CELLS ; \ Allow for slightly more portable code - -: 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 ; - -: CR '\n' emit ; -: SPACE BL emit ; - -: [COMPILE] IMMEDIATE - WORD \ get the next word - FIND \ find it in the dictionary - >CFA \ get its codeword - , \ and compile that -; - -: RECURSE IMMEDIATE - LATEST @ \ LATEST points to the word being compiled at the moment - >CFA \ get the codeword - , \ compile it -; - -: DEBUGON TRUE DEBUG ! ; -: DEBUGOFF FALSE DEBUG ! ; - -\ CONTROL STRUCTURES ---------------------------------------------------------------------- - -: IF IMMEDIATE - ' 0BRANCH , \ compile 0BRANCH - 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 - 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 - 0 , \ compile a dummy offset - SWAP \ now back-fill the original (IF) offset - DUP \ same as for THEN word above - HERE @ SWAP - - SWAP ! -; - -: BEGIN IMMEDIATE - HERE @ \ save location on the stack -; - -: UNTIL IMMEDIATE - ' 0BRANCH , \ compile 0BRANCH - 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 - , \ compile the offset here -; - -: WHILE IMMEDIATE - ' 0BRANCH , \ compile 0BRANCH - 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 - DUP - HERE @ SWAP - \ calculate the offset2 - SWAP ! \ and back-fill it in the original location -; - -: UNLESS IMMEDIATE - ' 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 , - HERE @ -; - -: ?DO IMMEDIATE - ' 2DUP , ' - , [COMPILE] IF - ' >R , ' >R , - ' LIT , HERE @ 0 , ' >R , - HERE @ -; - -: I RSP@ 3 - @ ; - -: J RSP@ 6 - @ ; - -: ?LEAVE IMMEDIATE - ' 0BRANCH , 13 , - ' R> , ' RDROP , ' RDROP , - ' LIT , HERE @ 7 + , ' DUP , ' -ROT , ' - , ' SWAP , ' ! , - ' BRANCH , - 0 , -; - -: LEAVE IMMEDIATE - ' LIT , -1 , - [COMPILE] ?LEAVE -; - -: +LOOP IMMEDIATE - ' DUP , \ Store copy of increment - - ' 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<= , - [COMPILE] ELSE - ' 0> , - [COMPILE] THEN - - \ Branch back to begining of loop kernel - ' 0BRANCH , HERE @ - , - - \ Clean up - ' 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) - [COMPILE] THEN -; - -: LOOP IMMEDIATE - ' LIT , 1 , - [COMPILE] +LOOP -; - -\ COMMENTS ---------------------------------------------------------------------- - -: ( IMMEDIATE - 1 \ allowed nested parens by keeping track of depth - BEGIN - KEY \ read next character - DUP '(' = IF \ open paren? - DROP \ drop the open paren - 1+ \ depth increases - ELSE - ')' = IF \ close paren? - 1- \ depth decreases - THEN - THEN - DUP 0= UNTIL \ continue until we reach matching close paren, depth 0 - DROP \ drop the depth counter -; - -( Some more complicated stack examples, showing the stack notation. ) -: NIP ( x y -- y ) SWAP DROP ; -: TUCK ( x y -- y x y ) DUP -ROT ; -: PICK ( x_u ... x_1 x_0 u -- x_u ... x_1 x_0 x_u ) - 1+ ( add one because of 'u' on the stack ) - PSP@ SWAP - ( add to the stack pointer ) - @ ( and fetch ) -; -: ROLL ( x_u x_u-1... x_0 u -- x_u-1 ... x_0 x_u ) - 1+ DUP PICK SWAP ( x_u x_u-1 ... x_0 x_u u+1 ) - PSP@ 1- SWAP - PSP@ 2- SWAP - DO - i 1+ @ i ! - LOOP - SWAP DROP -; - -( With the looping constructs, we can now write SPACES, which writes n spaces to stdout. ) -: SPACES ( n -- ) - DUP 0> IF - 0 DO SPACE LOOP - ELSE - DROP - THEN -; - -( Standard words for manipulating BASE. ) -: DECIMAL ( -- ) 10 BASE ! ; -: HEX ( -- ) 16 BASE ! ; - -( Compute absolute value. ) -: ABS ( n -- |n| ) - dup 0< if - negate - then -; - -: MAX ( n m -- max ) - 2dup - 0< if - swap drop - else - drop - then -; - -: MIN ( n m -- max ) - 2dup - 0> if - swap drop - else - drop - then -; - -( PRINTING NUMBERS ---------------------------------------------------------------------- ) - -( This is the underlying recursive definition of U. ) -: U. ( u -- ) - BASE @ /MOD ( width rem quot ) - ?DUP IF ( if quotient <> 0 then ) - RECURSE ( print the quotient ) - THEN - - ( print the remainder ) - DUP 10 < IF - '0' ( decimal digits 0..9 ) - ELSE - 10 - ( hex and beyond digits A..Z ) - 'A' - THEN - + - EMIT -; - -( This word returns the width (in characters) of an unsigned number in the current base ) -: UWIDTH ( u -- width ) - BASE @ / ( rem quot ) - ?DUP IF ( if quotient <> 0 then ) - RECURSE 1+ ( return 1+recursive call ) - ELSE - 1 ( return 1 ) - THEN -; - -: U.R ( u width -- ) - SWAP ( width u ) - DUP ( width u u ) - UWIDTH ( width u uwidth ) - ROT ( u uwidth width ) - SWAP - ( u width-uwidth ) - ( At this point if the requested width is narrower, we'll have a negative number on the stack. - Otherwise the number on the stack is the number of spaces to print. But SPACES won't print - a negative number of spaces anyway, so it's now safe to call SPACES ... ) - SPACES - ( ... and then call the underlying implementation of U. ) - U. -; - -: .R ( n width -- ) - SWAP ( width n ) - DUP 0< IF - NEGATE ( width u ) - 1 ( save a flag to remember that it was negative | width n 1 ) - -ROT ( 1 width u ) - SWAP ( 1 u width ) - 1- ( 1 u width-1 ) - ELSE - 0 ( width u 0 ) - -ROT ( 0 width u ) - SWAP ( 0 u width ) - THEN - SWAP ( flag width u ) - DUP ( flag width u u ) - UWIDTH ( flag width u uwidth ) - ROT ( flag u uwidth width ) - SWAP - ( flag u width-uwidth ) - - SPACES ( flag u ) - SWAP ( u flag ) - - IF ( was it negative? print the - character ) - '-' EMIT - THEN - - U. -; - -: . 0 .R SPACE ; - -: .S ( -- ) - '<' EMIT DEPTH U. '>' EMIT SPACE - PSP0 @ 1+ - BEGIN - DUP PSP@ 2 - <= - WHILE - DUP @ . - 1+ - REPEAT - DROP -; - -: U. U. SPACE ; - -( ? fetches the integer at an address and prints it. ) -: ? ( addr -- ) @ . ; - -( c a b WITHIN returns true if a <= c and c < b ) -: WITHIN - -ROT ( b c a ) - OVER ( b c a c ) - <= IF - > IF ( b c -- ) - TRUE - ELSE - FALSE - THEN - ELSE - 2DROP ( b c -- ) - FALSE - THEN -; - - -( 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 -- ) - - DUP 0<= IF - EXIT - THEN - - -ROT OVER - ( length src (dest-src) ) - -ROT DUP ROT + SWAP ( (dest-src) (src+length) src ) - - DO - I @ ( (dest-src) i@ ) - OVER I + ( (dest-src) i@ (dest-src+i) ) - ! ( (dest-src) ) - LOOP - - DROP -; - -( C, appends a byte to the current compiled word. ) -: C, - HERE @ C! - 1 HERE +! -; - -: S" IMMEDIATE ( -- addr len ) - STATE @ IF ( compiling? ) - ' 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 '"' <> - 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 ) - 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 - BEGIN - KEY - DUP '"' <> - WHILE - OVER C! ( save next character ) - 1+ ( increment address ) - REPEAT - DROP ( drop the final " character ) - 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 -; - -CR CR ." --- Welcome to TimForth! ---" CR CR +: \ IMMEDIATE + #IB @ >IN ! +; \ We can now comment! + +\ Compile core definitions +\ (These files must be compiled in order!) + +include lib_1_basic.4th +include lib_2_control.4th +include lib_3_input.4th +include lib_4_comments.4th +include lib_5_printnum.4th +include lib_6_strings.4th +include lib_7_variables.4th +include lib_8_vocab.4th +include lib_9_decompiler.4th +include lib_10_misc.4th +include lib_11_extensions.4th + +: LICENSE + CR + ." This program is free software: you can redistribute it and/or modify" CR + ." it under the terms of the GNU General Public License as published by" CR + ." the Free Software Foundation, either version 3 of the License, or" CR + ." (at your option) any later version." CR + ." " CR + ." This program is distributed in the hope that it will be useful," CR + ." but WITHOUT ANY WARRANTY; without even the implied warranty of" CR + ." MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the" CR + ." GNU General Public License for more details." CR + ." " CR + ." You should have received a copy of the GNU General Public License" CR + ." along with this program. If not, see http://www.gnu.org/licenses/." CR +; + +: WELCOME + SKIP-WELCOME @ INVERT IF + ." Welcome to forth.jl!" CR CR + + ." Copyright (C) 2016 Tim Vaughan" CR + ." This program comes with ABSOLUTELY NO WARRANY; for details type 'license'" CR + ." Type 'bye' or press Ctrl+D to exit." CR CR + THEN +; +welcome