couple of helpers for parsing expressions in parens

2 files changed, 330 insertions, 0 deletions

diff --git a/apps/desugar b/apps/desugar
index 7fb466f7..7c223612 100755
--- a/apps/desugar
+++ b/apps/desugar
Binary files differdiff --git a/apps/desugar.subx b/apps/desugar.subx
index bcdf806d..c4dc6ed8 100644
--- a/apps/desugar.subx
+++ b/apps/desugar.subx
@@ -792,6 +792,336 @@ test-emit-indirect-mode-2:
     5d/pop-to-EBP
     c3/return
 
+# update line->read to end of string literal surrounded by double quotes
+# line->read must start out at a double-quote
+skip-until-close-paren:  # line : (address stream)
+    # . 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
+    # ECX = line
+    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .                         1/r32/ECX   8/disp8         .                 # copy *(EBP+8) to ECX
+    # EAX = skip-until-close-paren-in-slice(&line->data[line->read], &line->data[line->write])
+    # . . push &line->data[line->write]
+    8b/copy                         1/mod/*+disp8   1/rm32/ECX    .           .                         2/r32/EDX   8/disp8         .                 # copy *(ECX+8) to EDX
+    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    1/base/ECX  2/index/EDX   .           2/r32/EDX   0xc/disp8       .                 # copy ECX+EDX+12 to EDX
+    52/push-EDX
+    # . . push &line->data[line->read]
+    8b/copy                         1/mod/*+disp8   1/rm32/ECX    .           .                         2/r32/EDX   4/disp8         .                 # copy *(ECX+4) to EDX
+    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    1/base/ECX  2/index/EDX   .           2/r32/EDX   0xc/disp8       .                 # copy ECX+EDX+12 to EDX
+    52/push-EDX
+    # . . call
+    e8/call  skip-until-close-paren-in-slice/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # line->read = EAX - line->data
+    29/subtract                     3/mod/direct    0/rm32/EAX    .           .             .           1/r32/ECX   .               .                 # subtract ECX from EAX
+    2d/subtract-from-EAX  0xc/imm32
+    89/copy                         1/mod/*+disp8   1/rm32/ECX    .           .                         0/r32/EAX   4/disp8         .                 # copy EAX to *(ECX+4)
+$skip-until-close-paren:end:
+    # . restore registers
+    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-until-close-paren:
+    # . prolog
+    55/push-EBP
+    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
+    # setup
+    # . clear-stream(_test-input-stream)
+    # . . push args
+    68/push  _test-input-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-input-stream, "*(abc) def")
+    # .                   indices:  0123 45
+    # . . push args
+    68/push  "*(abc) def"/imm32
+    68/push  _test-input-stream/imm32
+    # . . call
+    e8/call  write/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # precondition: line->read == 0
+    # . . push args
+    68/push  "F - test-skip-until-close-paren/precondition"/imm32
+    68/push  0/imm32
+    b8/copy-to-EAX  _test-input-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
+    # skip-until-close-paren(_test-input-stream)
+    # . . push args
+    68/push  _test-input-stream/imm32
+    # . . call
+    e8/call  skip-until-close-paren/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+    # check-ints-equal(line->read, 6, msg)
+    # . . push args
+    68/push  "F - test-skip-until-close-paren"/imm32
+    68/push  6/imm32
+    b8/copy-to-EAX  _test-input-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
+    # . epilog
+    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
+    5d/pop-to-EBP
+    c3/return
+
+test-skip-until-close-paren-ignores-spaces:
+    # . prolog
+    55/push-EBP
+    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
+    # setup
+    # . clear-stream(_test-input-stream)
+    # . . push args
+    68/push  _test-input-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-input-stream, "*(a b)/yz")
+    # . . push args
+    68/push  "*(a b)/yz"/imm32
+    68/push  _test-input-stream/imm32
+    # . . call
+    e8/call  write/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # precondition: line->read == 0
+    # . . push args
+    68/push  "F - test-skip-until-close-paren-ignores-spaces/precondition"/imm32
+    68/push  0/imm32
+    b8/copy-to-EAX  _test-input-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
+    # skip-until-close-paren(_test-input-stream)
+    # . . push args
+    68/push  _test-input-stream/imm32
+    # . . call
+    e8/call  skip-until-close-paren/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+    # check-ints-equal(line->read, 6, msg)
+    # . . push args
+    68/push  "F - test-skip-until-close-paren-ignores-spaces"/imm32
+    68/push  6/imm32
+    b8/copy-to-EAX  _test-input-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
+    # . epilog
+    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
+    5d/pop-to-EBP
+    c3/return
+
+test-skip-until-close-paren-works-from-mid-stream:
+    # . prolog
+    55/push-EBP
+    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
+    # setup
+    # . clear-stream(_test-input-stream)
+    # . . push args
+    68/push  _test-input-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-input-stream, "0 *(a b)/yz")
+    # . . push args
+    68/push  "0 *(a b)/yz"/imm32
+    68/push  _test-input-stream/imm32
+    # . . call
+    e8/call  write/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # precondition: _test-input-stream->read == 2
+    c7          0/subop/copy        1/mod/*+disp8   0/rm32/EAX    .           .             .           .           4/disp8         2/imm32           # copy to *(EAX+4)
+    # skip-until-close-paren(_test-input-stream)
+    # . . push args
+    68/push  _test-input-stream/imm32
+    # . . call
+    e8/call  skip-until-close-paren/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
+    # check-ints-equal(_test-input-stream->read, 8, msg)
+    # . . push args
+    68/push  "F - test-skip-until-close-paren-works-from-mid-stream"/imm32
+    68/push  8/imm32
+    b8/copy-to-EAX  _test-input-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
+    # . epilog
+    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
+    5d/pop-to-EBP
+    c3/return
+
+skip-until-close-paren-in-slice:  # curr : (address byte), end : (address byte) -> new_curr/EAX
+    # . prolog
+    55/push-EBP
+    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
+    # . save registers
+    51/push-ECX
+    52/push-EDX
+    # ECX = curr
+    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .                         1/r32/ECX   8/disp8         .                 # copy *(EBP+8) to ECX
+    # EDX = end
+    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .                         2/r32/EDX   0xc/disp8         .               # copy *(EBP+12) to EDX
+    # EAX = 0
+    31/xor                          3/mod/direct    0/rm32/EAX    .           .             .           0/r32/EAX   .               .                 # clear EAX
+    # skip initial dquote
+    41/increment-ECX
+$skip-until-close-paren-in-slice:loop:
+    # if (curr >= end) return curr
+    39/compare                      3/mod/direct    1/rm32/ECX    .           .             .           2/r32/EDX   .               .                 # compare ECX with EDX
+    73/jump-if-greater-unsigned-or-equal  $skip-until-close-paren-in-slice:return-curr/disp8
+    # AL = *curr
+    8a/copy-byte                    0/mod/indirect  1/rm32/ECX    .           .             .           0/r32/AL    .               .                 # copy byte at *ECX to AL
+$skip-until-close-paren-in-slice:check-close:
+    # if (EAX == ')') break
+    3d/compare-EAX-and  0x29/imm32/close-paren
+    74/jump-if-equal  $skip-until-close-paren-in-slice:break/disp8
+    # ++curr
+    41/increment-ECX
+    eb/jump  $skip-until-close-paren-in-slice:loop/disp8
+$skip-until-close-paren-in-slice:break:
+    # skip close-paren itself
+    41/increment-ECX
+$skip-until-close-paren-in-slice:return-curr:
+    # return curr
+    89/copy                         3/mod/direct    0/rm32/EAX    .           .             .           1/r32/ECX   .               .                 # copy ECX to EAX
+$skip-until-close-paren-in-slice:end:
+    # . restore registers
+    5a/pop-to-EDX
+    59/pop-to-ECX
+    # . epilog
+    89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
+    5d/pop-to-EBP
+    c3/return
+
+test-skip-until-close-paren-in-slice:
+    # . prolog
+    55/push-EBP
+    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
+    # setup: (EAX..ECX) = "*(abc) def"
+    b8/copy-to-EAX  "*(abc) def"/imm32
+    8b/copy                         0/mod/indirect  0/rm32/EAX    .           .             .           1/r32/ECX   .               .                 # copy *EAX to ECX
+    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    0/base/EAX  1/index/ECX   .           1/r32/ECX   4/disp8         .                 # copy EAX+ECX+4 to ECX
+    05/add-to-EAX  4/imm32
+    # EAX = skip-until-close-paren-in-slice(EAX, ECX)
+    # . . push args
+    51/push-ECX
+    50/push-EAX
+    # . . call
+    e8/call  skip-until-close-paren-in-slice/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # check-ints-equal(ECX-EAX, 4, msg)  # number of chars remaining after the string literal
+    # . . push args
+    68/push  "F - test-skip-until-close-paren-in-slice"/imm32
+    68/push  4/imm32
+    # . . push ECX-EAX
+    29/subtract                     3/mod/direct    1/rm32/ECX    .           .             .           0/r32/EAX   .               .                 # subtract EAX from ECX
+    51/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
+
+test-skip-until-close-paren-in-slice-ignores-spaces:
+    # . prolog
+    55/push-EBP
+    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
+    # setup: (EAX..ECX) = "*(a b)/yz"
+    b8/copy-to-EAX  "*(a b)/yz"/imm32
+    8b/copy                         0/mod/indirect  0/rm32/EAX    .           .             .           1/r32/ECX   .               .                 # copy *EAX to ECX
+    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    0/base/EAX  1/index/ECX   .           1/r32/ECX   4/disp8         .                 # copy EAX+ECX+4 to ECX
+    05/add-to-EAX  4/imm32
+    # EAX = skip-until-close-paren-in-slice(EAX, ECX)
+    # . . push args
+    51/push-ECX
+    50/push-EAX
+    # . . call
+    e8/call  skip-until-close-paren-in-slice/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # check-ints-equal(ECX-EAX, 3, msg)  # number of chars remaining after the string literal
+    # . . push args
+    68/push  "F - test-skip-until-close-paren-in-slice-ignores-spaces"/imm32
+    68/push  3/imm32
+    # . . push ECX-EAX
+    29/subtract                     3/mod/direct    1/rm32/ECX    .           .             .           0/r32/EAX   .               .                 # subtract EAX from ECX
+    51/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
+
+test-skip-until-close-paren-in-slice-stops-at-end:
+    # . prolog
+    55/push-EBP
+    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
+    # setup: (EAX..ECX) = "*(abc"  # unbalanced dquote
+    b8/copy-to-EAX  "*(abc"/imm32
+    8b/copy                         0/mod/indirect  0/rm32/EAX    .           .             .           1/r32/ECX   .               .                 # copy *EAX to ECX
+    8d/copy-address                 1/mod/*+disp8   4/rm32/sib    0/base/EAX  1/index/ECX   .           1/r32/ECX   4/disp8         .                 # copy EAX+ECX+4 to ECX
+    05/add-to-EAX  4/imm32
+    # EAX = skip-until-close-paren-in-slice(EAX, ECX)
+    # . . push args
+    51/push-ECX
+    50/push-EAX
+    # . . call
+    e8/call  skip-until-close-paren-in-slice/disp32
+    # . . discard args
+    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
+    # check-ints-equal(ECX-EAX, 0, msg)  # skipped to end of slice
+    # . . push args
+    68/push  "F - test-skip-until-close-paren-in-slice-stops-at-end"/imm32
+    68/push  0/imm32
+    # . . push ECX-EAX
+    29/subtract                     3/mod/direct    1/rm32/ECX    .           .             .           0/r32/EAX   .               .                 # subtract EAX from ECX
+    51/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
+
 == data
 Registers:  # (table string int)
   # a table is a stream