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Diffstat (limited to 'apps/mulisp.subx')
| -rw-r--r-- | apps/mulisp.subx | 233 |
1 files changed, 0 insertions, 233 deletions
diff --git a/apps/mulisp.subx b/apps/mulisp.subx deleted file mode 100644 index b433fa17..00000000 --- a/apps/mulisp.subx +++ /dev/null @@ -1,233 +0,0 @@ -# Toy lisp interpreter. Incomplete. -# -# To run: -# $ ./translate_subx init.linux 0*.subx apps/mulisp.subx -# $ ./a.elf -# 42 -# => 42 -# ^D -# $ - -== code - -Entry: # run tests if necessary, a REPL if not - # . prologue - 89/<- %ebp 4/r32/esp - # initialize heap - (new-segment *Heap-size Heap) - { - # if (argc <= 1) break - 81 7/subop/compare *ebp 1/imm32 - 7e/jump-if-<= break/disp8 - # if (argv[1] != "test")) break - (kernel-string-equal? *(ebp+8) "test") # => eax - 3d/compare-eax-and 0/imm32/false - 74/jump-if-= break/disp8 - # - (run-tests) - # syscall(exit, *Num-test-failures) - 8b/-> *Num-test-failures 3/r32/ebx - eb/jump $main:end/disp8 - } - (repl Stdin Stdout) - # syscall(exit, 0) - bb/copy-to-ebx 0/imm32 -$main:end: - e8/call syscall_exit/disp32 - -# Data structures -# -# Lisp is dynamically typed. Values always carry around knowledge of their -# type. -# -# There's several types of types in the description below, so we need a -# glossary and notational convention to disambiguate: -# lisp type: what Lisp code can see. Looks how you type it at the prompt. -# nil num char string symbol pair array -# type tag: the numeric code for a lisp type. All caps. -# NIL NUM CHAR STRING SYMBOL PAIR ARRAY -# memory type: a type specifying memory layout at the SubX level. Starts -# with a '$'. -# $int $array $(addr _) -# -# Lisp values are represented in memory by the _cell_ data structure. A cell -# is 12 bytes long: -# tag: $int (4 bytes; we're not concerned about wasting space) -# data: 8 bytes whose contents and meaning depend on tag -# -# What values of the different Lisp types look like in memory: -# - nil: cell{ tag: 0/NIL, data: 0 0 } -# - num: cell{ tag: 1/NUM, data: $int 0 } -# data contains the number -# - char: cell{ tag: 2/CHAR, data: $int 0 } -# data contains the utf-8 code of the character (no compound glyphs, no -# modifiers, etc., etc.) -# - string: cell{ tag: 3/STRING, data: $(addr stream byte) -# data contains an (addr array byte) containing the string in utf-8 -# - symbol: cell{ tag: 4/SYMBOL, data: $(addr array byte) 0 } -# data contains an (addr array byte) containing the name of the symbol in utf-8 -# alternatively, data could contain an index into the table of interned symbols -# - pair: cell{ tag: 5/PAIR, data: $(addr cell) $(addr cell) } -# data contains pointers to car and cdr -# - array: cell{ tag: 6/ARRAY, data: $tag $(addr stream data) -# data contains a pointer to an array of 8-byte data fields and the common -# tag for them all - -repl: # in: (addr buffered-file), out: (addr buffered-file) - # . prologue - 55/push-ebp - 89/<- %ebp 4/r32/esp - # . save registers - 50/push-eax - { - (lisp-read Stdin) # => eax: (handle cell) - # if (eax == 0) break - 3d/compare-eax-and 0/imm32 - 74/jump-if-= break/disp8 - # - (lisp-eval %eax) # => eax: (handle cell) - (lisp-print Stdout %eax) - eb/jump loop/disp8 - } -$repl:end: - # . restore registers - 58/pop-to-eax - # . epilogue - 89/<- %esp 5/r32/ebp - 5d/pop-to-ebp - c3/return - -# numbers start with a digit and are always in hex -# characters start with a backslash -# pairs start with '(' -# arrays start with '[' -# symbols start with anything else but quote, backquote, unquote or splice -# only one s-expression per line -lisp-read: # in: (addr buffered-file) -> eax: (handle cell) - # . prologue - 55/push-ebp - 89/<- %ebp 4/r32/esp - # . save registers - 51/push-ecx - # var s/ecx: (stream byte 512) - 81 5/subop/subtract %esp 0x200/imm32 - 68/push 0x200/imm32/size - 68/push 0/imm32/read - 68/push 0/imm32/write - 89/<- %ecx 4/r32/esp - { - # read line into s - (clear-stream %ecx) - (read-line-buffered *(ebp+8) %ecx) - # if (s->write == 0) return null - { - 81 7/subop/compare *ecx 0/imm32 - 75/jump-if-!= break/disp8 - b8/copy-to-eax 0/imm32/eof - eb/jump $lisp-read:end/disp8 - } - # ... -#? eb/jump loop/disp8 - } - # return s - 89/<- %eax 1/r32/ecx -$lisp-read:end: - # . reclaim locals - 81 0/subop/add %esp 0x20c/imm32 - # . restore registers - 59/pop-to-ecx - # . epilogue - 89/<- %esp 5/r32/ebp - 5d/pop-to-ebp - c3/return - -# lisp-read: in: (addr buffered-file) -> (handle cell) -# token tmp = next-mulisp-token(in) -# if is-int(tmp) return cell(tmp) -# if is-string(tmp) return cell(tmp) -# if is-pair(tmp) ... -# if is-array(tmp) ... - -next-mulisp-token: # in: (addr buffered-file), line: (addr stream byte), result: (addr slice) - # pseudocode: - # if (line->read >= line->write) - # read-line-buffered(in, line) - # recurse - # if (line->data[line->read] == ' ') - # skip-chars-matching-whitespace(line) - # recurse - # if (line->data[line->read] == '#') - # read-line-buffered(in, line) - # recurse - # eax = line->data[line->read] - # if (eax == '"') - # result->start = &line->data[line->read] - # skip-string(in) - # result->end = &line->data[line->read] - # return - # if (is-digit(eax)) - # result->start = &line->data[line->read] - # skip-hex-int(in) - # result->end = &line->data[line->read] - # return - # if (eax in '(' ')' '[' ']') - # result->start = &line->data[line->read] - # ++line->read - # result->en = &line->data[line->read] - # return - # else - # result->start = &line->data[line->read] - # skip-lisp-word(line) - # result->en = &line->data[line->read] - # return - # - # . prologue - 55/push-ebp - 89/<- %ebp 4/r32/esp - # . save registers -$next-mulisp-token:end: - # . reclaim locals - # . restore registers - # . epilogue - 89/<- %esp 5/r32/ebp - 5d/pop-to-ebp - c3/return - -new-int-cell: # in: (addr slice) -> eax: (handle cell) - -new-string-cell: # in: (addr slice) -> eax: (handle cell) - -lisp-eval: # in: (addr cell) -> eax: (handle cell) - # . prologue - 55/push-ebp - 89/<- %ebp 4/r32/esp - # . save registers - 8b/-> *(ebp+8) 0/r32/eax -$lisp-eval:end: - # . restore registers - # . epilogue - 89/<- %esp 5/r32/ebp - 5d/pop-to-ebp - c3/return - -lisp-print: # out: (addr buffered-file), x: (addr cell) - # . prologue - 55/push-ebp - 89/<- %ebp 4/r32/esp - # . save registers - # write(x) - (write-buffered Stdout "=> ") - (write-stream-data Stdout *(ebp+0xc)) - (flush Stdout) -$lisp-print:end: - # . restore registers - # . epilogue - 89/<- %esp 5/r32/ebp - 5d/pop-to-ebp - c3/return - -== data - -Nil: - 0/imm32/tag - 0/imm32/data |