From 3d1c4216ede8c628558c9fe700fb2be1aa08b473 Mon Sep 17 00:00:00 2001 From: Kartik Agaram Date: Mon, 2 Nov 2020 21:24:53 -0800 Subject: 7162 --- html/apps/mulisp.subx.html | 295 --------------------------------------------- 1 file changed, 295 deletions(-) delete mode 100644 html/apps/mulisp.subx.html (limited to 'html/apps/mulisp.subx.html') diff --git a/html/apps/mulisp.subx.html b/html/apps/mulisp.subx.html deleted file mode 100644 index 62316dfb..00000000 --- a/html/apps/mulisp.subx.html +++ /dev/null @@ -1,295 +0,0 @@ - - - - -Mu - apps/mulisp.subx - - - - - - - - - - -https://github.com/akkartik/mu/blob/master/apps/mulisp.subx -
-  1 # Toy lisp interpreter. Incomplete.
-  2 #
-  3 # To run:
-  4 #   $ ./translate_subx init.linux 0*.subx apps/mulisp.subx
-  5 #   $ ./a.elf
-  6 #   42
-  7 #   => 42
-  8 #   ^D
-  9 #   $
- 10 
- 11 == code
- 12 
- 13 Entry:  # run tests if necessary, a REPL if not
- 14     # . prologue
- 15     89/<- %ebp 4/r32/esp
- 16     # initialize heap
- 17     (new-segment *Heap-size Heap)
- 18     {
- 19       # if (argc <= 1) break
- 20       81 7/subop/compare *ebp 1/imm32
- 21       7e/jump-if-<= break/disp8
- 22       # if (argv[1] != "test")) break
- 23       (kernel-string-equal? *(ebp+8) "test")  # => eax
- 24       3d/compare-eax-and 0/imm32/false
- 25       74/jump-if-= break/disp8
- 26       #
- 27       (run-tests)
- 28       # syscall(exit, *Num-test-failures)
- 29       8b/-> *Num-test-failures 3/r32/ebx
- 30       eb/jump $main:end/disp8
- 31     }
- 32     (repl Stdin Stdout)
- 33     # syscall(exit, 0)
- 34     bb/copy-to-ebx 0/imm32
- 35 $main:end:
- 36     e8/call  syscall_exit/disp32
- 37 
- 38 # Data structures
- 39 #
- 40 # Lisp is dynamically typed. Values always carry around knowledge of their
- 41 # type.
- 42 #
- 43 # There's several types of types in the description below, so we need a
- 44 # glossary and notational convention to disambiguate:
- 45 #   lisp type: what Lisp code can see. Looks how you type it at the prompt.
- 46 #     nil num char string symbol pair array
- 47 #   type tag: the numeric code for a lisp type. All caps.
- 48 #     NIL NUM CHAR STRING SYMBOL PAIR ARRAY
- 49 #   memory type: a type specifying memory layout at the SubX level. Starts
- 50 #   with a '$'.
- 51 #     $int $array $(addr _)
- 52 #
- 53 # Lisp values are represented in memory by the _cell_ data structure. A cell
- 54 # is 12 bytes long:
- 55 #   tag: $int (4 bytes; we're not concerned about wasting space)
- 56 #   data: 8 bytes whose contents and meaning depend on tag
- 57 #
- 58 # What values of the different Lisp types look like in memory:
- 59 #   - nil: cell{ tag: 0/NIL, data: 0 0 }
- 60 #   - num: cell{ tag: 1/NUM, data: $int 0 }
- 61 #     data contains the number
- 62 #   - char: cell{ tag: 2/CHAR, data: $int 0 }
- 63 #     data contains the utf-8 code of the character (no compound glyphs, no
- 64 #     modifiers, etc., etc.)
- 65 #   - string: cell{ tag: 3/STRING, data: $(addr stream byte)
- 66 #     data contains an (addr array byte) containing the string in utf-8
- 67 #   - symbol: cell{ tag: 4/SYMBOL, data: $(addr array byte) 0 }
- 68 #     data contains an (addr array byte) containing the name of the symbol in utf-8
- 69 #     alternatively, data could contain an index into the table of interned symbols
- 70 #   - pair: cell{ tag: 5/PAIR, data: $(addr cell) $(addr cell)  }
- 71 #     data contains pointers to car and cdr
- 72 #   - array: cell{ tag: 6/ARRAY, data: $tag $(addr stream data)
- 73 #     data contains a pointer to an array of 8-byte data fields and the common
- 74 #     tag for them all
- 75 
- 76 repl:  # in: (addr buffered-file), out: (addr buffered-file)
- 77     # . prologue
- 78     55/push-ebp
- 79     89/<- %ebp 4/r32/esp
- 80     # . save registers
- 81     50/push-eax
- 82     {
- 83       (lisp-read Stdin)  # => eax: (handle cell)
- 84       # if (eax == 0) break
- 85       3d/compare-eax-and 0/imm32
- 86       74/jump-if-= break/disp8
- 87       #
- 88       (lisp-eval %eax)  # => eax: (handle cell)
- 89       (lisp-print Stdout %eax)
- 90       eb/jump loop/disp8
- 91     }
- 92 $repl:end:
- 93     # . restore registers
- 94     58/pop-to-eax
- 95     # . epilogue
- 96     89/<- %esp 5/r32/ebp
- 97     5d/pop-to-ebp
- 98     c3/return
- 99 
-100 # numbers start with a digit and are always in hex
-101 # characters start with a backslash
-102 # pairs start with '('
-103 # arrays start with '['
-104 # symbols start with anything else but quote, backquote, unquote or splice
-105 # only one s-expression per line
-106 lisp-read:  # in: (addr buffered-file) -> eax: (handle cell)
-107     # . prologue
-108     55/push-ebp
-109     89/<- %ebp 4/r32/esp
-110     # . save registers
-111     51/push-ecx
-112     # var s/ecx: (stream byte 512)
-113     81 5/subop/subtract %esp 0x200/imm32
-114     68/push 0x200/imm32/size
-115     68/push 0/imm32/read
-116     68/push 0/imm32/write
-117     89/<- %ecx 4/r32/esp
-118     {
-119       # read line into s
-120       (clear-stream %ecx)
-121       (read-line-buffered *(ebp+8) %ecx)
-122       # if (s->write == 0) return null
-123       {
-124         81 7/subop/compare *ecx 0/imm32
-125         75/jump-if-!= break/disp8
-126         b8/copy-to-eax 0/imm32/eof
-127         eb/jump $lisp-read:end/disp8
-128       }
-129       # ...
-130 #?       eb/jump loop/disp8
-131     }
-132     # return s
-133     89/<- %eax 1/r32/ecx
-134 $lisp-read:end:
-135     # . reclaim locals
-136     81 0/subop/add %esp 0x20c/imm32
-137     # . restore registers
-138     59/pop-to-ecx
-139     # . epilogue
-140     89/<- %esp 5/r32/ebp
-141     5d/pop-to-ebp
-142     c3/return
-143 
-144 # lisp-read:  in: (addr buffered-file) -> (handle cell)
-145 #   token tmp = next-mulisp-token(in)
-146 #   if is-int(tmp) return cell(tmp)
-147 #   if is-string(tmp) return cell(tmp)
-148 #   if is-pair(tmp) ...
-149 #   if is-array(tmp) ...
-150 
-151 next-mulisp-token:  # in: (addr buffered-file), line: (addr stream byte), result: (addr slice)
-152     # pseudocode:
-153     #   if (line->read >= line->write)
-154     #     read-line-buffered(in, line)
-155     #     recurse
-156     #   if (line->data[line->read] == ' ')
-157     #     skip-chars-matching-whitespace(line)
-158     #     recurse
-159     #   if (line->data[line->read] == '#')
-160     #     read-line-buffered(in, line)
-161     #     recurse
-162     #   eax = line->data[line->read]
-163     #   if (eax == '"')
-164     #     result->start = &line->data[line->read]
-165     #     skip-string(in)
-166     #     result->end = &line->data[line->read]
-167     #     return
-168     #   if (is-digit(eax))
-169     #     result->start = &line->data[line->read]
-170     #     skip-hex-int(in)
-171     #     result->end = &line->data[line->read]
-172     #     return
-173     #   if (eax in '(' ')' '[' ']')
-174     #     result->start = &line->data[line->read]
-175     #     ++line->read
-176     #     result->en = &line->data[line->read]
-177     #     return
-178     #   else
-179     #     result->start = &line->data[line->read]
-180     #     skip-lisp-word(line)
-181     #     result->en = &line->data[line->read]
-182     #     return
-183     #
-184     # . prologue
-185     55/push-ebp
-186     89/<- %ebp 4/r32/esp
-187     # . save registers
-188 $next-mulisp-token:end:
-189     # . reclaim locals
-190     # . restore registers
-191     # . epilogue
-192     89/<- %esp 5/r32/ebp
-193     5d/pop-to-ebp
-194     c3/return
-195 
-196 new-int-cell:  # in: (addr slice) -> eax: (handle cell)
-197 
-198 new-string-cell:  # in: (addr slice) -> eax: (handle cell)
-199 
-200 lisp-eval:  # in: (addr cell) -> eax: (handle cell)
-201     # . prologue
-202     55/push-ebp
-203     89/<- %ebp 4/r32/esp
-204     # . save registers
-205     8b/-> *(ebp+8) 0/r32/eax
-206 $lisp-eval:end:
-207     # . restore registers
-208     # . epilogue
-209     89/<- %esp 5/r32/ebp
-210     5d/pop-to-ebp
-211     c3/return
-212 
-213 lisp-print:  # out: (addr buffered-file), x: (addr cell)
-214     # . prologue
-215     55/push-ebp
-216     89/<- %ebp 4/r32/esp
-217     # . save registers
-218     # write(x)
-219     (write-buffered Stdout "=> ")
-220     (write-stream-data Stdout *(ebp+0xc))
-221     (flush Stdout)
-222 $lisp-print:end:
-223     # . restore registers
-224     # . epilogue
-225     89/<- %esp 5/r32/ebp
-226     5d/pop-to-ebp
-227     c3/return
-228 
-229 == data
-230 
-231 Nil:
-232   0/imm32/tag
-233   0/imm32/data
-
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