4913

7 files changed, 472 insertions, 2 deletions

diff --git a/subx/069next-token.subx b/subx/069next-token.subx
new file mode 100644
index 00000000..2ec1777f
--- /dev/null
+++ b/subx/069next-token.subx
@@ -0,0 +1,450 @@
+== code
+#   instruction                     effective address                                                   register    displacement    immediate
+# . op          subop               mod             rm32          base        index         scale       r32
+# . 1-3 bytes   3 bits              2 bits          3 bits        3 bits      3 bits        2 bits      2 bits      0/1/2/4 bytes   0/1/2/4 bytes
+
+# main:
+    e8/call  run-tests/disp32  # 'run-tests' is a function created automatically by SubX. It calls all functions that start with 'test-'.
+    # syscall(exit, Num-test-failures)
+    8b/copy                         0/mod/indirect  5/rm32/.disp32            .             .           3/r32/EBX   Num-test-failures/disp32          # copy *Num-test-failures to EBX
+    b8/copy-to-EAX  1/imm32/exit
+    cd/syscall  0x80/imm8
+
+# new data structure: a slice is an open interval of addresses [start, end) that includes 'start' but not 'end'
+
+# extract the next run of characters that are different from a given 'delimiter'
+# on eof return an empty interval
+next-token:  # in : (address stream), delimiter : byte, out : (address slice)
+    # . prolog
+    55/push-EBP
+    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
+    # . save registers
+    50/push-EAX
+    51/push-ECX
+    56/push-ESI
+    57/push-EDI
+    # ESI = in
+    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           6/r32/ESI   8/disp8         .                 # copy *(EBP+8) to ESI
+    # EDI = out
+    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           7/r32/EDI   0x10/disp8      .                 # copy *(EBP+16) to EDI
+    # skip-chars-matching(in, delimiter)
+    # . . push args
+    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           0xc/disp8       .                 # push *(EBP+12)
+    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           8/disp8         .                 # push *(EBP+8)
+    # . . call
+    e8/call  skip-chars-matching/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # out->start = &in->data[in->read]
+    8b/copy                         1/mod/*+disp8   6/rm32/ESI    .           .             .           1/r32/ECX   4/disp8         .                 # copy *(ESI+4) to ECX
+    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    6/base/ESI  1/index/ECX   .           0/r32/EAX   0xc/disp8       .                 # copy ESI+ECX+12 to EAX
+    89/copy                         0/mod/indirect  7/rm32/EDI    .           .             .           0/r32/EAX   .               .                 # copy EAX to *EDI
+    # skip-chars-not-matching(in, delimiter)
+    # . . push args
+    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           0xc/disp8       .                 # push *(EBP+12)
+    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           8/disp8         .                 # push *(EBP+8)
+    # . . call
+    e8/call  skip-chars-not-matching/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # out->end = &in->data[in->read]
+    8b/copy                         1/mod/*+disp8   6/rm32/ESI    .           .             .           1/r32/ECX   4/disp8         .                 # copy *(ESI+4) to ECX
+    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    6/base/ESI  1/index/ECX   .           0/r32/EAX   0xc/disp8       .                 # copy ESI+ECX+12 to EAX
+    89/copy                         1/mod/*+disp8   7/rm32/EDI    .           .             .           0/r32/EAX   4/disp8         .                 # copy EAX to *(EDI+4)
+    # . restore registers
+    5f/pop-to-EDI
+    5e/pop-to-ESI
+    59/pop-to-ECX
+    58/pop-to-EAX
+    # . epilog
+    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
+    5d/pop-to-EBP
+    c3/return
+
+test-next-token:
+    # . prolog
+    55/push-EBP
+    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
+    # setup
+    # . clear-stream(_test-stream)
+    # . . push args
+    68/push  _test-stream/imm32
+    # . . call
+    e8/call  clear-stream/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+    # var slice/ECX = {0, 0}
+    68/push  0/imm32/end
+    68/push  0/imm32/start
+    89/copy                         3/mod/direct    1/rm32/ECX    .           .             .           4/r32/ESP   .               .                 # copy ESP to ECX
+    # write(_test-stream, "  ab")
+    # . . push args
+    68/push  "  ab"/imm32
+    68/push  _test-stream/imm32
+    # . . call
+    e8/call  write/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # next-token(_test-stream, 0x20/space, slice)
+    # . . push args
+    51/push-ECX
+    68/push  0x20/imm32
+    68/push  _test-stream/imm32
+    # . . call
+    e8/call  next-token/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
+    # check-ints-equal(slice->start - _test-stream->data, 2, msg)
+    # . check-ints-equal(slice->start - _test-stream, 14, msg)
+    # . . push args
+    68/push  "F - test-next-token: start"/imm32
+    68/push  0xe/imm32
+    # . . push slice->start - _test-stream
+    8b/copy                         0/mod/indirect  1/rm32/ECX    .           .             .           0/r32/EAX   .               .                 # copy *ECX to EAX
+    81          5/subop/subtract    3/mod/direct    0/rm32/EAX    .           .             .           .           .               _test-stream/imm32 # subtract from EAX
+    50/push-EAX
+    # . . call
+    e8/call  check-ints-equal/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
+    # check-ints-equal(slice->end - _test-stream->data, 4, msg)
+    # . check-ints-equal(slice->end - _test-stream, 16, msg)
+    # . . push args
+    68/push  "F - test-next-token: end"/imm32
+    68/push  0x10/imm32
+    # . . push slice->end - _test-stream
+    8b/copy                         1/mod/*+disp8   1/rm32/ECX    .           .             .           0/r32/EAX   4/disp8         .                 # copy *(ECX+4) to EAX
+    81          5/subop/subtract    3/mod/direct    0/rm32/EAX    .           .             .           .           .               _test-stream/imm32 # subtract from EAX
+    50/push-EAX
+    # . . call
+    e8/call  check-ints-equal/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
+    # . epilog
+    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
+    5d/pop-to-EBP
+    c3/return
+
+test-next-token-eof:
+    # . prolog
+    55/push-EBP
+    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
+    # setup
+    # . clear-stream(_test-stream)
+    # . . push args
+    68/push  _test-stream/imm32
+    # . . call
+    e8/call  clear-stream/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+    # var slice/ECX = {0, 0}
+    68/push  0/imm32/end
+    68/push  0/imm32/start
+    89/copy                         3/mod/direct    1/rm32/ECX    .           .             .           4/r32/ESP   .               .                 # copy ESP to ECX
+    # write nothing to _test-stream
+    # next-token(_test-stream, 0x20/space, slice)
+    # . . push args
+    51/push-ECX
+    68/push  0x20/imm32
+    68/push  _test-stream/imm32
+    # . . call
+    e8/call  next-token/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
+    # check-ints-equal(slice->end, slice->start, msg)
+    # . . push args
+    68/push  "F - test-next-token-eof"/imm32
+    ff          6/subop/push        1/mod/*+disp8   1/rm32/ECX    .           .             .           .           4/disp8         .                 # push *(ECX+4)
+    ff          6/subop/push        0/mod/indirect  1/rm32/ECX    .           .             .           .           .               .                 # push *ECX
+    # . . call
+    e8/call  check-ints-equal/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
+    # . epilog
+    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
+    5d/pop-to-EBP
+    c3/return
+
+skip-chars-matching:  # in : (address stream), delimiter : byte
+    # . prolog
+    55/push-EBP
+    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
+    # . save registers
+    50/push-EAX
+    51/push-ECX
+    52/push-EDX
+    56/push-ESI
+    # ESI = in
+    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           6/r32/ESI   8/disp8         .                 # copy *(EBP+8) to ESI
+    # ECX = in->read
+    8b/copy                         1/mod/*+disp8   6/rm32/ESI    .           .             .           1/r32/ECX   4/disp8         .                 # copy *(ESI+4) to ECX
+    # EBX = in->write
+    8b/copy                         0/mod/indirect  6/rm32/ESI    .           .             .           3/r32/EBX   .               .                 # copy *ESI to EBX
+    # EDX = delimiter
+    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           2/r32/EDX   0xc/disp8       .                 # copy *(EBP+12) to EDX
+$skip-chars-matching:loop:
+    # if (in->read >= in->write) break
+    3b/compare                      3/mod/direct    3/rm32/EBX    .           .             .           1/r32/ECX   .               .                 # compare ECX with *EBX
+    7d/jump-if-greater-or-equal  $skip-chars-matching:end/disp8
+    # EAX = in->data[in->read]
+    31/xor                          3/mod/direct    0/rm32/EAX    .           .             .           0/r32/EAX   .               .                 # clear EAX
+    8a/copy-byte                    1/mod/*+disp8   4/rm32/sib    6/base/ESI  1/index/ECX   .           0/r32/AL    0xc/disp8       .                 # copy byte at *(ESI+ECX+12) to AL
+    # if (EAX != delimiter) break
+    39/compare                      3/mod/direct    0/rm32/EAX    .           .             .           2/r32/EDX   .               .                 # compare EAX and EDX
+    75/jump-if-not-equal  $skip-chars-matching:end/disp8
+    # ++in->read
+    41/inc-ECX
+    eb/jump  $skip-chars-matching:loop/disp8
+$skip-chars-matching:end:
+    # persist in->read
+    89/copy                         1/mod/*+disp8   6/rm32/ESI    .           .             .           1/r32/ECX   4/disp8         .                 # copy ECX to *(ESI+4)
+    # . restore registers
+    5e/pop-to-ESI
+    5a/pop-to-EDX
+    59/pop-to-ECX
+    58/pop-to-EAX
+    # . epilog
+    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
+    5d/pop-to-EBP
+    c3/return
+
+test-skip-chars-matching:
+    # setup
+    # . clear-stream(_test-stream)
+    # . . push args
+    68/push  _test-stream/imm32
+    # . . call
+    e8/call  clear-stream/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+    # write(_test-stream, "  ab")
+    # . . push args
+    68/push  "  ab"/imm32
+    68/push  _test-stream/imm32
+    # . . call
+    e8/call  write/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # skip-chars-matching(_test-stream, 0x20/space)
+    # . . push args
+    68/push  0x20/imm32
+    68/push  _test-stream/imm32
+    # . . call
+    e8/call  skip-chars-matching/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # check-ints-equal(_test-stream->read, 2, msg)
+    # . . push args
+    68/push  "F - test-skip-chars-matching"/imm32
+    68/push  2/imm32
+    # . . push *_test-stream->read
+    b8/copy-to-EAX  _test-stream/imm32
+    ff          6/subop/push        1/mod/*+disp8   0/rm32/EAX    .           .             .           .           4/disp8         .                 # push *(EAX+4)
+    # . . call
+    e8/call  check-ints-equal/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
+    # end
+    c3/return
+
+test-skip-chars-matching-none:
+    # setup
+    # . clear-stream(_test-stream)
+    # . . push args
+    68/push  _test-stream/imm32
+    # . . call
+    e8/call  clear-stream/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+    # write(_test-stream, "ab")
+    # . . push args
+    68/push  "ab"/imm32
+    68/push  _test-stream/imm32
+    # . . call
+    e8/call  write/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # skip-chars-matching(_test-stream, 0x20/space)
+    # . . push args
+    68/push  0x20/imm32
+    68/push  _test-stream/imm32
+    # . . call
+    e8/call  skip-chars-matching/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # check-ints-equal(_test-stream->read, 0, msg)
+    # . . push args
+    68/push  "F - test-skip-chars-matching-none"/imm32
+    68/push  0/imm32
+    # . . push *_test-stream->read
+    b8/copy-to-EAX  _test-stream/imm32
+    ff          6/subop/push        1/mod/*+disp8   0/rm32/EAX    .           .             .           .           4/disp8         .                 # push *(EAX+4)
+    # . . call
+    e8/call  check-ints-equal/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
+    # end
+    c3/return
+
+# minor fork of 'skip-chars-matching'
+skip-chars-not-matching:  # in : (address stream), delimiter : byte
+    # . prolog
+    55/push-EBP
+    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
+    # . save registers
+    50/push-EAX
+    51/push-ECX
+    52/push-EDX
+    56/push-ESI
+    # ESI = in
+    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           6/r32/ESI   8/disp8         .                 # copy *(EBP+8) to ESI
+    # ECX = in->read
+    8b/copy                         1/mod/*+disp8   6/rm32/ESI    .           .             .           1/r32/ECX   4/disp8         .                 # copy *(ESI+4) to ECX
+    # EBX = in->write
+    8b/copy                         0/mod/indirect  6/rm32/ESI    .           .             .           3/r32/EBX   .               .                 # copy *ESI to EBX
+    # EDX = delimiter
+    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           2/r32/EDX   0xc/disp8       .                 # copy *(EBP+12) to EDX
+$skip-chars-not-matching:loop:
+    # if (in->read >= in->write) break
+    3b/compare                      3/mod/direct    3/rm32/EBX    .           .             .           1/r32/ECX   .               .                 # compare ECX with *EBX
+    7d/jump-if-greater-or-equal  $skip-chars-not-matching:end/disp8
+    # EAX = in->data[in->read]
+    31/xor                          3/mod/direct    0/rm32/EAX    .           .             .           0/r32/EAX   .               .                 # clear EAX
+    8a/copy-byte                    1/mod/*+disp8   4/rm32/sib    6/base/ESI  1/index/ECX   .           0/r32/AL    0xc/disp8       .                 # copy byte at *(ESI+ECX+12) to AL
+    # if (EAX == delimiter) break
+    39/compare                      3/mod/direct    0/rm32/EAX    .           .             .           2/r32/EDX   .               .                 # compare EAX and EDX
+    74/jump-if-equal  $skip-chars-not-matching:end/disp8
+    # ++in->read
+    41/inc-ECX
+    eb/jump  $skip-chars-not-matching:loop/disp8
+$skip-chars-not-matching:end:
+    # persist in->read
+    89/copy                         1/mod/*+disp8   6/rm32/ESI    .           .             .           1/r32/ECX   4/disp8         .                 # copy ECX to *(ESI+4)
+    # . restore registers
+    5e/pop-to-ESI
+    5a/pop-to-EDX
+    59/pop-to-ECX
+    58/pop-to-EAX
+    # . epilog
+    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
+    5d/pop-to-EBP
+    c3/return
+
+test-skip-chars-not-matching:
+    # setup
+    # . clear-stream(_test-stream)
+    # . . push args
+    68/push  _test-stream/imm32
+    # . . call
+    e8/call  clear-stream/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+    # write(_test-stream, "ab ")
+    # . . push args
+    68/push  "ab "/imm32
+    68/push  _test-stream/imm32
+    # . . call
+    e8/call  write/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # skip-chars-not-matching(_test-stream, 0x20/space)
+    # . . push args
+    68/push  0x20/imm32
+    68/push  _test-stream/imm32
+    # . . call
+    e8/call  skip-chars-not-matching/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # check-ints-equal(_test-stream->read, 2, msg)
+    # . . push args
+    68/push  "F - test-skip-chars-not-matching"/imm32
+    68/push  2/imm32
+    # . . push *_test-stream->read
+    b8/copy-to-EAX  _test-stream/imm32
+    ff          6/subop/push        1/mod/*+disp8   0/rm32/EAX    .           .             .           .           4/disp8         .                 # push *(EAX+4)
+    # . . call
+    e8/call  check-ints-equal/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
+    # end
+    c3/return
+
+test-skip-chars-not-matching-none:
+    # setup
+    # . clear-stream(_test-stream)
+    # . . push args
+    68/push  _test-stream/imm32
+    # . . call
+    e8/call  clear-stream/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+    # write(_test-stream, " ab")
+    # . . push args
+    68/push  " ab"/imm32
+    68/push  _test-stream/imm32
+    # . . call
+    e8/call  write/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # skip-chars-not-matching(_test-stream, 0x20/space)
+    # . . push args
+    68/push  0x20/imm32
+    68/push  _test-stream/imm32
+    # . . call
+    e8/call  skip-chars-not-matching/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # check-ints-equal(_test-stream->read, 0, msg)
+    # . . push args
+    68/push  "F - test-skip-chars-not-matching-none"/imm32
+    68/push  0/imm32
+    # . . push *_test-stream->read
+    b8/copy-to-EAX  _test-stream/imm32
+    ff          6/subop/push        1/mod/*+disp8   0/rm32/EAX    .           .             .           .           4/disp8         .                 # push *(EAX+4)
+    # . . call
+    e8/call  check-ints-equal/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
+    # end
+    c3/return
+
+test-skip-chars-not-matching-all:
+    # setup
+    # . clear-stream(_test-stream)
+    # . . push args
+    68/push  _test-stream/imm32
+    # . . call
+    e8/call  clear-stream/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+    # write(_test-stream, "ab")
+    # . . push args
+    68/push  "ab"/imm32
+    68/push  _test-stream/imm32
+    # . . call
+    e8/call  write/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # skip-chars-not-matching(_test-stream, 0x20/space)
+    # . . push args
+    68/push  0x20/imm32
+    68/push  _test-stream/imm32
+    # . . call
+    e8/call  skip-chars-not-matching/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # check-ints-equal(_test-stream->read, 2, msg)
+    # . . push args
+    68/push  "F - test-skip-chars-not-matching-all"/imm32
+    68/push  2/imm32
+    # . . push *_test-stream->read
+    b8/copy-to-EAX  _test-stream/imm32
+    ff          6/subop/push        1/mod/*+disp8   0/rm32/EAX    .           .             .           .           4/disp8         .                 # push *(EAX+4)
+    # . . call
+    e8/call  check-ints-equal/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
+    # end
+    c3/return
+
+# . . vim:nowrap:textwidth=0
diff --git a/subx/apps/crenshaw2-1 b/subx/apps/crenshaw2-1
index 20ac912a..354683d2 100755
--- a/subx/apps/crenshaw2-1
+++ b/subx/apps/crenshaw2-1
Binary files differdiff --git a/subx/apps/crenshaw2-1b b/subx/apps/crenshaw2-1b
index 37145d9c..37576192 100755
--- a/subx/apps/crenshaw2-1b
+++ b/subx/apps/crenshaw2-1b
Binary files differdiff --git a/subx/apps/factorial b/subx/apps/factorial
index c05e588f..72217cdd 100755
--- a/subx/apps/factorial
+++ b/subx/apps/factorial
Binary files differdiff --git a/subx/apps/handle b/subx/apps/handle
index d6d0a7f5..ce489c0a 100755
--- a/subx/apps/handle
+++ b/subx/apps/handle
Binary files differdiff --git a/subx/apps/hex b/subx/apps/hex
index 932a3ceb..936ebdce 100755
--- a/subx/apps/hex
+++ b/subx/apps/hex
Binary files differdiff --git a/subx/apps/pack.subx b/subx/apps/pack.subx
index 1cf57867..bad21e0f 100644
--- a/subx/apps/pack.subx
+++ b/subx/apps/pack.subx
@@ -117,7 +117,7 @@ $main:end:
 #   word = name until '/', then 0 or more metadata separated by '/'
 #
 # we won't bother saving the internal structure of lines; reparsing should be cheap using two primitives:
-#   next-token(stream, delim char) -> slice (start, end pointer)
+#   next-token(stream, delim char) -> slice (start, end pointers)
 #   slice-equal?(slice, kernel string)
 
 # helpers:
@@ -136,7 +136,6 @@ $main:end:
 #   emit(out : &buffered-file, word : &slice)
 #   has-metadata?(word : &slice, s : &kernel-string) -> bool
 
-# the main entry point
 convert:  # in : (address buffered-file), out : (address buffered-file), err : (address buffered-file), ed : (address exit-descriptor) -> <void>
     # pseudocode:
     #   line = new-stream(512, 1)
@@ -157,6 +156,27 @@ convert:  # in : (address buffered-file), out : (address buffered-file), err : (
     5d/pop-to-EBP
     c3/return
 
+# (re)compute the bounds of the next word in the line
+next-word:  # line : (address stream byte), out : (address slice)
+    # . prolog
+    55/push-EBP
+    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
+    # . save registers
+    # skip-whitespace(line)
+    # . . push args
+    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           8/disp8         .                 # push *(EBP+8)
+    # . . call
+    e8/call  skip-whitespace/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+    # if line->data[line->read] == '#' return (&line->data[line->read], &line->data[line->write])
+    # return next-token(line, ' ')
+    # . restore registers
+    # . epilog
+    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
+    5d/pop-to-EBP
+    c3/return
+
 == data
 
 # . . vim:nowrap:textwidth=0