forth.forth

   1 \ This program is free software: you can redistribute it and/or modify
   2 \ it under the terms of the GNU General Public License as published by
   3 \ the Free Software Foundation, either version 3 of the License, or
   4 \ (at your option) any later version.
   5 \
   6 \ This program is distributed in the hope that it will be useful,
   7 \ but WITHOUT ANY WARRANTY; without even the implied warranty of
   8 \ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   9 \ GNU General Public License for more details.
  10 \
  11 \ You should have received a copy of the GNU General Public License
  12 \ along with this program.  If not, see <http://www.gnu.org/licenses/>.
  13
  14 \ word EXECUTE 12 define
  15 16500 execute WORD 16500 29 execute
  16 word DEFINE 29 29 execute
  17 word RINIT 3 define
  18 word NOOP 13 define
  19 word MODE 14336 define
  20 word EXECUTE-WORD 16680 define
  21 word EXECUTE-NUM 16720 define
  22 word INTERPRET 16400 define
  23 word KEY 5 define
  24 word WORD-START 20 define
  25 word WORD-PUT 19 define
  26 word WORD-END 23 define
  27 word STRING-START 39 define
  28 word STRING-PUT 40 define
  29 word STRING-END 41 define
  30 word NUMBER 22 define
  31 word FIND 21 define
  32 word FIND-DOES 44 define
  33 word DEFINE-DOES 45 define
  34 word QUIT 16384 define
  35 word BYE 25 define
  36 word WORDS 27 define
  37 word CHANNEL-IN 35 define
  38 word CHANNEL-OUT 48 define
  39 word CHANNEL-OPEN 51 define
  40 word CHANNEL-AWAIT 50 define
  41 word !HERE 36 define
  42 word HERE 28 define
  43
  44 word STACKTRACE 46 define
  45 word FETCH 47 define
  46
  47 word ; 1 define
  48 word JZ: 14 define
  49 word JNZ: 15 define
  50 word J-1: 24 define
  51 word JMP: 18 define
  52 word , 33 define
  53 word + 7 define
  54 word - 34 define
  55 word =? 37 define
  56 word WS? 17 define
  57 word . 9 define
  58 word .S 38 define
  59 word @ 10 define
  60 word @8u 53 define
  61 word @+ 42 define
  62 word ! 11 define
  63 word !+ 43 define
  64 word LIT 2 define
  65 word DUP 6 define
  66 word 2DUP 30 define
  67 word DROP 16 define
  68 word 2DROP 32 define
  69 word SWAP 26 define
  70 word ROT 31 define
  71 word -ROT 54 define
  72
  73 \ ' "TICK" returns address of word's execution semantics
  74 word ' here define
  75 word word find , word find find , word ; find ,
  76
  77 \ : "COLON" sets execution semantics
  78 word : here define
  79 word : here define-does
  80 ' word , ' here , ' define , ' ; ,
  81
  82 \ :> "DOES" sets compilation semantics
  83 word :> here define-does
  84 : :> ' word , ' here , ' define-does , ' ; ,
  85
  86 \ ::> "COLON DOES" sets execution and compilation semantics
  87 word ::> here define-does
  88 word ::> here define
  89 ' word , ' 2dup , ' here , ' define-does , ' here , ' define , ' ; ,
  90
  91 \ write the execution semantics of a word to memory
  92 : MEMORIZE-WORD ' dup , ' JNZ: , here 12 + , ' 2drop , ' ; ,
  93 ' 2dup , ' find , ' dup , ' JZ: , here 16 + , ' , , ' 2drop , ' ; ,
  94 ' drop , ' lit , ' lit , ' , , ' execute-num , ' , , ' ; ,
  95
  96 \ change interpreter semantics to "memorize-word"
  97 ::> MEMORIZING ' lit , ' memorize-word , ' lit , ' mode , ' ! , ' ; ,
  98
  99 \ memorize the compiler
 100 \memorizing
 101 \: executing lit execute-word lit mode ! ;
 102 \: FINISH-" drop string-end ;
 103 \: BSLASH-" drop key string-put JMP: \here \8 \+ \,
 104 \: " string-start \: KLOOP key 92 =? JNZ: bslash-" 34 =? JNZ: finish-" string-put JMP: KLOOP
 105 \: DO"    \:> " " swap lit lit , , lit lit , , ;
 106 \: DOIF   \:> IF lit JZ: , here dup , ;
 107 \: DOELSE \:> ELSE lit JMP: , here dup , here -rot ! ;
 108 \: DOTHEN \:> THEN here swap ! ;
 109 \: COMPILE-WORD dup
 110 \doif 2dup find-does dup
 111   \doif rot 2drop execute ;
 112   \dothen drop 2dup find dup
 113   \doif , 2drop ;
 114   \dothen drop lit lit , execute-num , ;
 115 \dothen 2drop \do" Compilation Error: null word" .s bye
 116 \: compiling lit compile-word lit mode ! ;
 117
 118 \ compile the rest of the compiler
 119 \compiling
 120
 121 \ ; "RET" compilation semantics: ends a function and returns to executing mode
 122 :> ; lit \' ; \, , lit \' ; \, , executing \' ; \,
 123
 124 \ ;; "SEMIRET" compilation semantics: simply writes a return instruction
 125 :> ;; lit \' ; \, , ;
 126
 127 \ <: "OVERLOAD COLON" extend previous execution semantics of word
 128 ::> <: \compiling word 2dup find dup if here swap , define else drop here define
 129 then compiling ;
 130
 131 \ <:> "OVERLOAD COLON DOES" extend previous compilation semantics of word
 132 ::> <:> \compiling word 2dup find-does dup if here swap , define-does else drop
 133 here define-does then compiling ;
 134
 135 \ execution semantics of COLON, DOES, and COLON DOES now extended to
 136 \ automatically switch to compilation mode
 137 <: : compiling ;
 138 <: :> compiling ;
 139 <: ::> compiling ;
 140
 141 \ Multi-line comments
 142 ::> ( key 41 =? swap -1 =? swap drop + if ;; then JMP: \' ( \, ;
 143
 144 (
 145   End of bootstrap process
 146   beyond this point, all hope is lost
 147 )
 148
 149 \ Set the number conversion base
 150 : BASE 14348 ! ;
 151 : BASE10 10 base ;
 152
 153 \ TICK compilation semantics
 154 :> ' lit lit , word find , ;
 155 \ "TICK DOES" (get compilation semantics execution token)
 156 : '> word find-does ;
 157 :> '> word find-does , ;
 158
 159 \ Include a remote file
 160 : REQUIRE" ' quit channel-open dup \' " \, fetch channel-await ;
 161
 162 \ Let's try it
 163 REQUIRE" { \"url\": \"forth/test-watfor.forth\" }"
 164
 165 \ Print intro string
 166 " watForth-32 Interactive CLI:
 167 " .s