5058

3 files changed, 251 insertions, 245 deletions

diff --git a/subx/apps/pack b/subx/apps/pack
index 3f96f27d..e75a5447 100755
--- a/subx/apps/pack
+++ b/subx/apps/pack
Binary files differdiff --git a/subx/apps/pack.subx b/subx/apps/pack.subx
index 65b0f64c..583ee218 100644
--- a/subx/apps/pack.subx
+++ b/subx/apps/pack.subx
@@ -6240,251 +6240,6 @@ test-convert-instruction-handles-imm8-operand:
     5d/pop-to-EBP
     c3/return
 
-# (re)compute the bounds of the next word in the line
-# return empty string on reaching end of file
-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
-    50/push-EAX
-    51/push-ECX
-    56/push-ESI
-    57/push-EDI
-    # ESI = line
-    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   0xc/disp8       .                 # copy *(EBP+12) to EDI
-    # skip-chars-matching(line, ' ')
-    # . . push args
-    68/push  0x20/imm32/space
-    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
-$next-word:check0:
-    # if (line->read >= line->write) clear out and return
-    # . EAX = line->read
-    8b/copy                         1/mod/*+disp8   6/rm32/ESI    .           .             .           0/r32/EAX   4/disp8         .                 # copy *(ESI+4) to EAX
-    # . if (EAX < line->write) goto next check
-    3b/compare                      0/mod/indirect  6/rm32/ESI    .           .             .           0/r32/EAX   .               .                 # compare EAX with *ESI
-    7c/jump-if-lesser  $next-word:check1/disp8
-    # . return out = {0, 0}
-    c7          0/subop/copy        0/mod/direct    7/rm32/EDI    .           .             .           .           .               0/imm32           # copy to *EDI
-    c7          0/subop/copy        1/mod/*+disp8   7/rm32/EDI    .           .             .           .           4/disp8         0/imm32           # copy to *(EDI+4)
-    eb/jump  $next-word:end/disp8
-$next-word:check1:
-    # out->start = &line->data[line->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
-    # if (line->data[line->read] == '#') out->end = &line->data[line->write]), skip rest of stream and return
-    # . EAX = line->data[line->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
-    # . compare
-    3d/compare-EAX-and  0x23/imm32/pound
-    75/jump-if-not-equal  $next-word:not-comment/disp8
-    # . out->end = &line->data[line->write]
-    8b/copy                         0/mod/indirect  6/rm32/ESI    .           .             .           0/r32/EAX   .               .                 # copy *ESI to EAX
-    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    6/base/ESI  0/index/EAX   .           0/r32/EAX   0xc/disp8       .                 # copy ESI+EAX+12 to EAX
-    89/copy                         1/mod/*+disp8   7/rm32/EDI    .           .             .           0/r32/EAX   4/disp8         .                 # copy EAX to *(EDI+4)
-    # . line->read = line->write
-    89/copy                         1/mod/*+disp8   6/rm32/ESI    .           .             .           0/r32/EAX   4/disp8         .                 # copy EAX to *(ESI+4)
-    # . return
-    eb/jump  $next-word:end/disp8
-$next-word:not-comment:
-    # otherwise skip-chars-not-matching-whitespace(line)  # including trailing newline
-    # . . push args
-    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           8/disp8         .                 # push *(EBP+8)
-    # . . call
-    e8/call  skip-chars-not-matching-whitespace/disp32
-    # . . discard args
-    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
-    # out->end = &line->data[line->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)
-$next-word:end:
-    # . 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-word:
-    # . 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-word(_test-stream, slice)
-    # . . push args
-    51/push-ECX
-    68/push  _test-stream/imm32
-    # . . call
-    e8/call  next-word/disp32
-    # . . discard args
-    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/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-word: 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-word: 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-word-returns-whole-comment:
-    # . 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, "  # a")
-    # . . push args
-    68/push  "  # a"/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-word(_test-stream, slice)
-    # . . push args
-    51/push-ECX
-    68/push  _test-stream/imm32
-    # . . call
-    e8/call  next-word/disp32
-    # . . discard args
-    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/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-word-returns-whole-comment: 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, 5, msg)
-    # . check-ints-equal(slice->end - _test-stream, 17, msg)
-    # . . push args
-    68/push  "F - test-next-word-returns-whole-comment: end"/imm32
-    68/push  0x11/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-word-returns-empty-string-on-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-word(_test-stream, slice)
-    # . . push args
-    51/push-ECX
-    68/push  _test-stream/imm32
-    # . . call
-    e8/call  next-word/disp32
-    # . . discard args
-    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
-    # check-ints-equal(slice->end - slice->start, 0, msg)
-    # . . push args
-    68/push  "F - test-next-word-returns-empty-string-on-eof"/imm32
-    68/push  0/imm32
-    # . . push slice->end - slice->start
-    8b/copy                         1/mod/*+disp8   1/rm32/ECX    .           .             .           0/r32/EAX   4/disp8         .                 # copy *(ECX+4) to EAX
-    2b/subtract                     0/mod/indirect  1/rm32/ECX    .           .             .           0/r32/EAX   .               .                 # subtract *ECX 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
-
 has-metadata?:  # word : (address slice), s : (address string) -> EAX : boolean
     # pseudocode:
     #   var twig : &slice = next-token-from-slice(word->start, word->end, '/')  # skip name
diff --git a/subx/apps/subx-common.subx b/subx/apps/subx-common.subx
new file mode 100644
index 00000000..49d6c4b6
--- /dev/null
+++ b/subx/apps/subx-common.subx
@@ -0,0 +1,251 @@
+# some common helpers shared by phases of the SubX converter
+
+== 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
+
+# (re)compute the bounds of the next word in the line
+# return empty string on reaching end of file
+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
+    50/push-EAX
+    51/push-ECX
+    56/push-ESI
+    57/push-EDI
+    # ESI = line
+    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   0xc/disp8       .                 # copy *(EBP+12) to EDI
+    # skip-chars-matching(line, ' ')
+    # . . push args
+    68/push  0x20/imm32/space
+    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
+$next-word:check0:
+    # if (line->read >= line->write) clear out and return
+    # . EAX = line->read
+    8b/copy                         1/mod/*+disp8   6/rm32/ESI    .           .             .           0/r32/EAX   4/disp8         .                 # copy *(ESI+4) to EAX
+    # . if (EAX < line->write) goto next check
+    3b/compare                      0/mod/indirect  6/rm32/ESI    .           .             .           0/r32/EAX   .               .                 # compare EAX with *ESI
+    7c/jump-if-lesser  $next-word:check1/disp8
+    # . return out = {0, 0}
+    c7          0/subop/copy        0/mod/direct    7/rm32/EDI    .           .             .           .           .               0/imm32           # copy to *EDI
+    c7          0/subop/copy        1/mod/*+disp8   7/rm32/EDI    .           .             .           .           4/disp8         0/imm32           # copy to *(EDI+4)
+    eb/jump  $next-word:end/disp8
+$next-word:check1:
+    # out->start = &line->data[line->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
+    # if (line->data[line->read] == '#') out->end = &line->data[line->write]), skip rest of stream and return
+    # . EAX = line->data[line->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
+    # . compare
+    3d/compare-EAX-and  0x23/imm32/pound
+    75/jump-if-not-equal  $next-word:not-comment/disp8
+    # . out->end = &line->data[line->write]
+    8b/copy                         0/mod/indirect  6/rm32/ESI    .           .             .           0/r32/EAX   .               .                 # copy *ESI to EAX
+    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    6/base/ESI  0/index/EAX   .           0/r32/EAX   0xc/disp8       .                 # copy ESI+EAX+12 to EAX
+    89/copy                         1/mod/*+disp8   7/rm32/EDI    .           .             .           0/r32/EAX   4/disp8         .                 # copy EAX to *(EDI+4)
+    # . line->read = line->write
+    89/copy                         1/mod/*+disp8   6/rm32/ESI    .           .             .           0/r32/EAX   4/disp8         .                 # copy EAX to *(ESI+4)
+    # . return
+    eb/jump  $next-word:end/disp8
+$next-word:not-comment:
+    # otherwise skip-chars-not-matching-whitespace(line)  # including trailing newline
+    # . . push args
+    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           8/disp8         .                 # push *(EBP+8)
+    # . . call
+    e8/call  skip-chars-not-matching-whitespace/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+    # out->end = &line->data[line->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)
+$next-word:end:
+    # . 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-word:
+    # . 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-word(_test-stream, slice)
+    # . . push args
+    51/push-ECX
+    68/push  _test-stream/imm32
+    # . . call
+    e8/call  next-word/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/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-word: 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-word: 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-word-returns-whole-comment:
+    # . 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, "  # a")
+    # . . push args
+    68/push  "  # a"/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-word(_test-stream, slice)
+    # . . push args
+    51/push-ECX
+    68/push  _test-stream/imm32
+    # . . call
+    e8/call  next-word/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/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-word-returns-whole-comment: 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, 5, msg)
+    # . check-ints-equal(slice->end - _test-stream, 17, msg)
+    # . . push args
+    68/push  "F - test-next-word-returns-whole-comment: end"/imm32
+    68/push  0x11/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-word-returns-empty-string-on-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-word(_test-stream, slice)
+    # . . push args
+    51/push-ECX
+    68/push  _test-stream/imm32
+    # . . call
+    e8/call  next-word/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # check-ints-equal(slice->end - slice->start, 0, msg)
+    # . . push args
+    68/push  "F - test-next-word-returns-empty-string-on-eof"/imm32
+    68/push  0/imm32
+    # . . push slice->end - slice->start
+    8b/copy                         1/mod/*+disp8   1/rm32/ECX    .           .             .           0/r32/EAX   4/disp8         .                 # copy *(ECX+4) to EAX
+    2b/subtract                     0/mod/indirect  1/rm32/ECX    .           .             .           0/r32/EAX   .               .                 # subtract *ECX 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