dwm.1


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.TH DWM 1 dwm-0.6
.SH NAME
dwm \- dynamic window manager
.SH SYNOPSIS
.B dwm
.RB [ \-v ]
.SH DESCRIPTION
.B dwm
is a dynamic window manager for X11. It manages windows in tiling and floating
modes. Either mode can be applied dynamically, depending on the application in
use and the task performed.
.P
In tiling mode windows are managed in a master and stacking column. The master
column contains the window which needs most attention at a time, whereas the
stacking column contains all other windows in a stack.  Dialog windows are
managed floating, however. In floating mode windows can be resized and moved
freely.
.P
Windows are grouped by tags. All windows with a specific tag can be viewed at a
time. But each window may contain more than one tag, which makes it visible in
several views.
.P
.B dwm
has a small status bar which reads the text displayed from standard
input, if written. It draws 1-pixel borders around windows to indicate the
focus state. Unfocused windows contain a small bar in front of the window
displaying the tags and the window title.
.SH OPTIONS
.TP
.B \-v
prints version information to standard output, then exits.
.SH USAGE
.TP
.B Mod1-Return
Zoom
.B window
to the 
.B master
column
.TP
.B Mod1-h
Focus previous
.B tag
.TP
.B Mod1-j
Focus next
.B window
.TP
.B Mod1-k
Focus previous
.B window
.TP
.B Mod1-l
Focus next
.B tag
.TP
.B Mod1-m
Maximize current
.B window
.TP
.B Mod1-[0..n]
Focus
.B nth tag
.TP
.B Mod1-space
Toggle between
.B tiled
and
.B floating
mode (affects
.BR "all windows" )
.TP
.B Mod1-Shift-[0..n]
Apply
.B nth tag
to current
.B window
.TP
.B Mod1-Shift-q
Quit
.B dwm
.TP
.B Mod1-Shift-Return
Start
.B terminal
.TP
.B Mod1-Control-[0..n]
Append
.B nth tag
to current
.B window
.TP
.B Mod1-Button1
Moves current
.B window
while dragging
.TP
.B Mod1-Button2
Lowers current
.B window
.TP
.B Mod1-Button3
Resizes current
.B window
while dragging
.SH CUSTOMIZATION
.B dwm
is customized by editing the file config.h of the source code.
This keeps it fast, secure and simple.
# new data structure: a slice is an open interval of addresses [start, end)
# that includes 'start' but not 'end'

== 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

#? Entry:  # run a single test, while debugging
#?     e8/call test-slice-starts-with-fails/disp32
#?     e8/call test-slice-starts-with-single-character/disp32
#?     # 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

slice-empty?:  # s : (address slice) -> EAX : boolean
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # . save registers
    51/push-ECX
    # ECX = s
    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           1/r32/ECX   8/disp8         .                 # copy *(EBP+8) to ECX
    # if (s->start == s->end) return true
    # . EAX = s->start
    8b/copy                         0/mod/indirect  1/rm32/ECX    .           .             .           0/r32/EAX   .               .                 # copy *ECX to EAX
    # . compare EAX with s->end
    39/compare                      1/mod/*+disp8   1/rm32/ECX    .           .             .           0/r32/EAX   4/disp8         .                 # compare EAX and *(ECX+4)
    b8/copy-to-EAX  1/imm32/true
    74/jump-if-equal  $slice-empty?:end/disp8
    b8/copy-to-EAX  0/imm32/false
$slice-empty?:end:
    # . restore registers
    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-slice-empty-true:
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # var slice/ECX = {34, 34}
    68/push  34/imm32/end
    68/push  34/imm32/start
    89/copy                         3/mod/direct    1/rm32/ECX    .           .             .           4/r32/ESP   .               .                 # copy ESP to ECX
    # slice-empty?(slice)
    # . . push args
    51/push-ECX
    # . . call
    e8/call  slice-empty?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # check-ints-equal(EAX, 1, msg)
    # . . push args
    68/push  "F - test-slice-empty-true"/imm32
    68/push  1/imm32
    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-slice-empty-false:
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # var slice/ECX = {34, 23}
    68/push  23/imm32/end
    68/push  34/imm32/start
    89/copy                         3/mod/direct    1/rm32/ECX    .           .             .           4/r32/ESP   .               .                 # copy ESP to ECX
    # slice-empty?(slice)
    # . . push args
    51/push-ECX
    # . . call
    e8/call  slice-empty?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # check-ints-equal(EAX, 0, msg)
    # . . push args
    68/push  "F - test-slice-empty-false"/imm32
    68/push  0/imm32
    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

slice-equal?:  # s : (address slice), p : (address string) -> EAX : boolean
    # pseudocode:
    #   currs = s->start
    #   maxs = s->end
    #   if (maxs - currs != p->length) return false
    #   currp = p->data
    #   while (currs < maxs)
    #     if (*currs != *currp) return false
    #     ++currs
    #     ++currp
    #   return true
    #
    # registers:
    #   currs: EDX
    #   maxs: ESI
    #   currp: EBX
    #   *currs: EAX
    #   *currp: ECX
    #
    # . 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
    53/push-EBX
    56/push-ESI
    # ESI = s
    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           6/r32/ESI   8/disp8         .                 # copy *(EBP+8) to ESI
    # currs/EDX = s->start
    8b/copy                         0/mod/indirect  6/rm32/ESI    .           .             .           2/r32/EDX   .               .                 # copy *ESI to EDX
    # maxs/ESI = s->end
    8b/copy                         1/mod/*+disp8   6/rm32/ESI    .           .             .           6/r32/ESI   4/disp8         .                 # copy *(ESI+4) to ESI
    # EBX = p
    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           3/r32/EBX   0xc/disp8       .                 # copy *(EBP+12) to EBX
    # EAX = maxs - currs
    89/copy                         3/mod/direct    0/rm32/EAX    .           .             .           6/r32/ESI   .               .                 # copy ESI to EAX
    29/subtract                     3/mod/direct    0/rm32/EAX    .           .             .           2/r32/EDX   .               .                 # subtract EDX from EAX
    # if (EAX != p->length) return false
    39/compare                      0/mod/indirect  3/rm32/EBX    .           .             .           0/r32/EAX   .               .                 # compare *EBX and EAX
    75/jump-if-not-equal  $slice-equal?:false/disp8
    # currp/EBX = p->data
    81          0/subop/add         3/mod/direct    3/rm32/EBX    .           .             .           .           .               4/imm32           # add to EBX
    # EAX = ECX = 0
    31/xor                          3/mod/direct    0/rm32/EAX    .           .             .           0/r32/EAX   .               .                 # clear EAX
    31/xor                          3/mod/direct    1/rm32/ECX    .           .             .           1/r32/ECX   .               .                 # clear ECX
$slice-equal?:loop:
    # if (currs >= maxs) return true
    39/compare                      3/mod/direct    2/rm32/EDX    .           .             .           6/r32/ESI   .               .                 # compare EDX and ESI
    7d/jump-if-greater-or-equal  $slice-equal?:true/disp8
    # AL = *currp
    8a/copy-byte                    0/mod/indirect  3/rm32/EBX    .           .             .           0/r32/AL    .               .                 # copy byte at *EBX to AL
    # CL = *currs
    8a/copy-byte                    0/mod/indirect  2/rm32/EDX    .           .             .           1/r32/CL    .               .                 # copy byte at *EDX to CL
    # if (EAX != ECX) return false
    39/compare                      3/mod/direct    0/rm32/EAX    .           .             .           1/r32/ECX   .               .                 # compare EAX and ECX
    75/jump-if-not-equal  $slice-equal?:false/disp8
    # ++currp
    43/increment-EBX
    # ++currs
    42/increment-EDX
    eb/jump $slice-equal?:loop/disp8
$slice-equal?:false:
    b8/copy-to-EAX  0/imm32
    eb/jump  $slice-equal?:end/disp8
$slice-equal?:true:
    b8/copy-to-EAX  1/imm32
$slice-equal?:end:
    # . restore registers
    5e/pop-to-ESI
    5b/pop-to-EBX
    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-slice-equal:
    # - slice-equal?(slice("Abc"), "Abc") == 1
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # var slice/ECX
    68/push  _test-slice-data-3/imm32/end
    68/push  _test-slice-data-0/imm32/start
    89/copy                         3/mod/direct    1/rm32/ECX    .           .             .           4/r32/ESP   .               .                 # copy ESP to ECX
    # EAX = slice-equal?(ECX, "Abc")
    # . . push args
    68/push  "Abc"/imm32
    51/push-ECX
    # . . call
    e8/call  slice-equal?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # check-ints-equal(EAX, 1, msg)
    # . . push args
    68/push  "F - test-slice-equal"/imm32
    68/push  1/imm32
    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-slice-equal-false:
    # - slice-equal?(slice("bcd"), "Abc") == 0
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # var slice/ECX
    68/push  _test-slice-data-4/imm32/end
    68/push  _test-slice-data-1/imm32/start
    89/copy                         3/mod/direct    1/rm32/ECX    .           .             .           4/r32/ESP   .               .                 # copy ESP to ECX
    # EAX = slice-equal?(ECX, "Abc")
    # . . push args
    68/push  "Abc"/imm32
    51/push-ECX
    # . . call
    e8/call  slice-equal?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # check-ints-equal(EAX, 0, msg)
    # . . push args
    68/push  "F - test-slice-equal-false"/imm32
    68/push  0/imm32
    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-slice-equal-too-long:
    # - slice-equal?(slice("Abcd"), "Abc") == 0
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # var slice/ECX
    68/push  _test-slice-data-4/imm32/end
    68/push  _test-slice-data-0/imm32/start
    89/copy                         3/mod/direct    1/rm32/ECX    .           .             .           4/r32/ESP   .               .                 # copy ESP to ECX
    # EAX = slice-equal?(ECX, "Abc")
    # . . push args
    68/push  "Abc"/imm32
    51/push-ECX
    # . . call
    e8/call  slice-equal?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # check-ints-equal(EAX, 0, msg)
    # . . push args
    68/push  "F - test-slice-equal-too-long"/imm32
    68/push  0/imm32
    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-slice-equal-too-short:
    # - slice-equal?(slice("A"), "Abc") == 0
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # var slice/ECX
    68/push  _test-slice-data-1/imm32/end
    68/push  _test-slice-data-0/imm32/start
    89/copy                         3/mod/direct    1/rm32/ECX    .           .             .           4/r32/ESP   .               .                 # copy ESP to ECX
    # EAX = slice-equal?(ECX, "Abc")
    # . . push args
    68/push  "Abc"/imm32
    51/push-ECX
    # . . call
    e8/call  slice-equal?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # check-ints-equal(EAX, 0, msg)
    # . . push args
    68/push  "F - test-slice-equal-too-short"/imm32
    68/push  0/imm32
    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-slice-equal-empty:
    # - slice-equal?(slice(""), "Abc") == 0
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # var slice/ECX
    68/push  _test-slice-data-0/imm32/end
    68/push  _test-slice-data-0/imm32/start
    89/copy                         3/mod/direct    1/rm32/ECX    .           .             .           4/r32/ESP   .               .                 # copy ESP to ECX
    # EAX = slice-equal?(ECX, "Abc")
    # . . push args
    68/push  "Abc"/imm32
    51/push-ECX
    # . . call
    e8/call  slice-equal?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # check-ints-equal(EAX, 0, msg)
    # . . push args
    68/push  "F - test-slice-equal-empty"/imm32
    68/push  0/imm32
    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-slice-equal-with-empty:
    # - slice-equal?(slice("Ab"), "") == 0
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # var slice/ECX
    68/push  _test-slice-data-2/imm32/end
    68/push  _test-slice-data-0/imm32/start
    89/copy                         3/mod/direct    1/rm32/ECX    .           .             .           4/r32/ESP   .               .                 # copy ESP to ECX
    # EAX = slice-equal?(ECX, "")
    # . . push args
    68/push  ""/imm32
    51/push-ECX
    # . . call
    e8/call  slice-equal?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # check-ints-equal(EAX, 0, msg)
    # . . push args
    68/push  "F - test-slice-equal-with-empty"/imm32
    68/push  0/imm32
    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-slice-equal-empty-with-empty:
    # - slice-equal?(slice(""), "") == 1
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # var slice/ECX
    68/push  _test-slice-data-0/imm32/end
    68/push  _test-slice-data-0/imm32/start
    89/copy                         3/mod/direct    1/rm32/ECX    .           .             .           4/r32/ESP   .               .                 # copy ESP to ECX
    # EAX = slice-equal?(ECX, "")
    # . . push args
    68/push  ""/imm32
    51/push-ECX
    # . . call
    e8/call  slice-equal?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # check-ints-equal(EAX, 1, msg)
    # . . push args
    68/push  "F - test-slice-equal-empty-with-empty"/imm32
    68/push  1/imm32
    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

slice-starts-with?:  # s : (address slice), head : (address string) -> EAX : boolean
    # pseudocode
    #   lenh = head->length
    #   if (lenh > s->end - s->start) return false
    #   i = 0
    #   currs = s->start
    #   currp = head->data
    #   while i < lenh
    #     if (*currs != *currh) return false
    #     ++i
    #     ++currs
    #     ++currh
    #   return true
    #
    # registers:
    #   currs: ESI
    #   currh: EDI
    #   *currs: EAX
    #   *currh: EBX
    #   i: ECX
    #   lenh: EDX
    #
    # . 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
    53/push-EBX
    56/push-ESI
    57/push-EDI
    # ESI = s
    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           6/r32/ESI   8/disp8         .                 # copy *(EBP+8) to ESI
    # ECX = s->end - s->start
    8b/copy                         1/mod/*+disp8   6/rm32/ESI    .           .             .           1/r32/ECX   4/disp8         .                 # copy *(ESI+4) to ECX
    2b/subtract                     0/mod/indirect  6/rm32/ESI    .           .             .           1/r32/ECX   .               .                 # subtract *ESI from ECX
    # EDI = head
    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           7/r32/EDI   0xc/disp8       .                 # copy *(EBP+12) to EDI
    # lenh/EDX = head->length
    8b/copy                         0/mod/indirect  7/rm32/EDI    .           .             .           2/r32/EDX   .               .                 # copy *EDI to EDX
    # if (lenh > s->end - s->start) return false
    39/compare                      3/mod/direct    2/rm32/EDX    .           .             .           1/r32/ECX   .               .                 # compare EDX with ECX
    7f/jump-if-greater  $slice-starts-with?:false/disp8
    # currs/ESI = s->start
    8b/subtract                     0/mod/indirect  6/rm32/ESI    .           .             .           6/r32/ESI   .               .                 # copy *ESI to ESI
    # currh/EDI = head->data
    81          0/subop/add         3/mod/direct    7/rm32/EDI    .           .             .           .           .               4/imm32           # add to EDI
    # i/ECX = 0
    31/xor                          3/mod/direct    1/rm32/ECX    .           .             .           1/r32/ECX   .               .                 # clear ECX
    # EAX = EBX = 0
    31/xor                          3/mod/direct    0/rm32/EAX    .           .             .           0/r32/EAX   .               .                 # clear EAX
    31/xor                          3/mod/direct    3/rm32/EBX    .           .             .           3/r32/EBX   .               .                 # clear EBX
$slice-starts-with?:loop:
    # if (i >= lenh) return true
    39/compare                      3/mod/direct    1/rm32/ECX    .           .             .           2/r32/EDX   .               .                 # compare ECX with EDX
    7d/jump-if-greater-or-equal  $slice-starts-with?:true/disp8
    # AL = *currs
    8a/copy-byte                    0/mod/indirect  6/rm32/ESI    .           .             .           0/r32/AL    .               .                 # copy byte at *ESI to AL
    # BL = *currh
    8a/copy-byte                    0/mod/indirect  7/rm32/EDI    .           .             .           3/r32/BL    .               .                 # copy byte at *EDI to BL
    # if (*currs != *currh) return false
    39/compare                      3/mod/direct    0/rm32/EAX    .           .             .           3/r32/EBX   .               .                 # compare EAX and EBX
    75/jump-if-not-equal  $slice-starts-with?:false/disp8
    # ++i
    41/increment-ECX
    # ++currs
    46/increment-ESI
    # ++currh
    47/increment-EDI
    eb/jump $slice-starts-with?:loop/disp8
$slice-starts-with?:true:
    b8/copy-to-EAX  1/imm32
    eb/jump  $slice-starts-with?:end/disp8
$slice-starts-with?:false:
    b8/copy-to-EAX  0/imm32
$slice-starts-with?:end:
    # . restore registers
    5f/pop-to-EDI
    5e/pop-to-ESI
    5b/pop-to-EBX
    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-slice-starts-with-single-character:
    # - slice-starts-with?(slice("Abc"), "A") == 1
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # var slice/ECX
    68/push  _test-slice-data-3/imm32/end
    68/push  _test-slice-data-0/imm32/start
    89/copy                         3/mod/direct    1/rm32/ECX    .           .             .           4/r32/ESP   .               .                 # copy ESP to ECX
    # EAX = slice-starts-with?(ECX, "A")
    # . . push args
    68/push  "A"/imm32
    51/push-ECX
    # . . call
    e8/call  slice-starts-with?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # check-ints-equal(EAX, 1, msg)
    # . . push args
    68/push  "F - test-slice-starts-with-single-character"/imm32
    68/push  1/imm32
    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-slice-starts-with-empty-string:
    # - slice-starts-with?(slice("Abc"), "") == 1
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # var slice/ECX
    68/push  _test-slice-data-3/imm32/end
    68/push  _test-slice-data-0/imm32/start
    89/copy                         3/mod/direct    1/rm32/ECX    .           .             .           4/r32/ESP   .               .                 # copy ESP to ECX
    # EAX = slice-starts-with?(ECX, "")
    # . . push args
    68/push  ""/imm32
    51/push-ECX
    # . . call
    e8/call  slice-starts-with?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # check-ints-equal(EAX, 1, msg)
    # . . push args
    68/push  "F - test-slice-starts-with-empty-string"/imm32
    68/push  1/imm32
    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-slice-starts-with-multiple-characters:
    # - slice-starts-with?(slice("Abc"), "Ab") == 1
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # var slice/ECX
    68/push  _test-slice-data-3/imm32/end
    68/push  _test-slice-data-0/imm32/start
    89/copy                         3/mod/direct    1/rm32/ECX    .           .             .           4/r32/ESP   .               .                 # copy ESP to ECX
    # EAX = slice-starts-with?(ECX, "Ab")
    # . . push args
    68/push  "Ab"/imm32
    51/push-ECX
    # . . call
    e8/call  slice-starts-with?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # check-ints-equal(EAX, 1, msg)
    # . . push args
    68/push  "F - test-slice-starts-with-multiple-characters"/imm32
    68/push  1/imm32
    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-slice-starts-with-entire-string:
    # - slice-starts-with?(slice("Abc"), "Abc") == 1
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # var slice/ECX
    68/push  _test-slice-data-3/imm32/end
    68/push  _test-slice-data-0/imm32/start
    89/copy                         3/mod/direct    1/rm32/ECX    .           .             .           4/r32/ESP   .               .                 # copy ESP to ECX
    # EAX = slice-starts-with?(ECX, "Abc")
    # . . push args
    68/push  "Abc"/imm32
    51/push-ECX
    # . . call
    e8/call  slice-starts-with?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # check-ints-equal(EAX, 1, msg)
    # . . push args
    68/push  "F - test-slice-starts-with-entire-string"/imm32
    68/push  1/imm32
    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-slice-starts-with-fails:
    # - slice-starts-with?(slice("Abc"), "Abd") == 1
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # var slice/ECX
    68/push  _test-slice-data-3/imm32/end
    68/push  _test-slice-data-0/imm32/start
    89/copy                         3/mod/direct    1/rm32/ECX    .           .             .           4/r32/ESP   .               .                 # copy ESP to ECX
    # EAX = slice-starts-with?(ECX, "Abd")
    # . . push args
    68/push  "Abd"/imm32
    51/push-ECX
    # . . call
    e8/call  slice-starts-with?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # check-ints-equal(EAX, 0, msg)
    # . . push args
    68/push  "F - test-slice-starts-with-fails"/imm32
    68/push  0/imm32
    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-slice-starts-with-fails-2:
    # - slice-starts-with?(slice("Abc"), "Ac") == 1
    # . prolog
    55/push-EBP
    89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
    # var slice/ECX
    68/push  _test-slice-data-3/imm32/end
    68/push  _test-slice-data-0/imm32/start
    89/copy                         3/mod/direct    1/rm32/ECX    .           .             .           4/r32/ESP   .               .                 # copy ESP to ECX
    # EAX = slice-starts-with?(ECX, "Ac")
    # . . push args
    68/push  "Ac"/imm32
    51/push-ECX
    # . . call
    e8/call  slice-starts-with?/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # check-ints-equal(EAX, 0, msg)
    # . . push args
    68/push  "F - test-slice-starts-with-fails-2"/imm32
    68/push  0/imm32
    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

write-slice:  # out : (address buffered-file), s : (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
    52/push-EDX
    53/push-EBX
    56/push-ESI
    57/push-EDI
    # ESI = s
    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           6/r32/ESI   0xc/disp8       .                 # copy *(EBP+12) to ESI
    # curr/ECX = s->start
    8b/copy                         0/mod/indirect  6/rm32/ESI    .           .             .           1/r32/ECX   .               .                 # copy *ESI to ECX
    # max/ESI = s->end
    8b/copy                         1/mod/*+disp8   6/rm32/ESI    .           .             .           6/r32/ESI   4/disp8         .                 # copy *(ESI+4) to ESI
    # EDI = f
    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .                         7/r32/EDI   8/disp8         .                 # copy *(EBP+8) to EDI
    # EDX = f->length
    8b/copy                         1/mod/*+disp8   7/rm32/EDI    .           .             .           2/r32/EDX   0xc/disp8       .                 # copy *(EDI+12) to EDX
    # EBX = f->write
    8b/copy                         1/mod/*+disp8   7/rm32/EDI    .           .             .           3/r32/EBX   4/disp8         .                 # copy *(EDI+4) to EBX
$write-slice:loop:
    # if (curr >= max) break
    39/compare                      3/mod/direct    1/rm32/ECX    .           .             .           6/r32/ESI   .               .                 # compare ECX with ESI
    7d/jump-if-greater-or-equal  $write-slice:loop-end/disp8
    # if (f->write >= f->length) flush and clear f's stream
    39/compare                      3/mod/direct    3/rm32/EBX    .           .             .           2/r32/EDX   .               .                 # compare EBX with EDX
    7c/jump-if-lesser  $write-slice:to-stream/disp8
    # . persist f->write
    89/copy                         1/mod/*+disp8   7/rm32/EDI    .           .             .           3/r32/EBX   4/disp8         .                 # copy EBX to *(EDI+4)
    # . flush(f)
    # . . push args
    57/push-EDI
    # . . call
    e8/call  flush/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # . clear-stream(stream = f+4)
    # . . push args
    8d/copy-address                 1/mod/*+disp8   7/rm32/EDI    .           .             .           0/r32/EAX   4/disp8         .                 # copy EDI+4 to EAX
    50/push-EAX
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # . f->write must now be 0; update its cache at EBX
    31/xor                          3/mod/direct    3/rm32/EBX    .           .             .           3/r32/EBX   .               .                 # clear EBX
$write-slice:to-stream:
    # f->data[f->write] = *in
    # . AL = *in
    31/xor                          3/mod/direct    0/rm32/EAX    .           .             .           0/r32/EAX   .               .                 # clear EAX
    8a/copy-byte                    0/mod/indirect  1/rm32/ECX    .           .             .           0/r32/AL    .               .                 # copy byte at *ECX to AL
    # . f->data[f->write] = AL
    88/copy-byte                    1/mod/*+disp8   4/rm32/sib    7/base/EDI  3/index/EBX   .           0/r32/AL    0x10/disp8      .                 # copy AL to *(EDI+EBX+16)
    # ++f->write
    43/increment-EBX
    # ++in
    41/increment-ECX
    eb/jump  $write-slice:loop/disp8
$write-slice:loop-end:
    # persist necessary variables from registers
    89/copy                         1/mod/*+disp8   7/rm32/EDI    .           .             .           3/r32/EBX   4/disp8         .                 # copy EBX to *(EDI+4)
$write-slice:end:
    # . restore registers
    5f/pop-to-EDI
    5e/pop-to-ESI
    5b/pop-to-EBX
    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-write-slice:
    # . 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
    # . clear-stream(_test-buffered-file+4)
    # . . push args
    b8/copy-to-EAX  _test-buffered-file/imm32
    05/add-to-EAX  4/imm32
    50/push-EAX
    # . . 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 = "Abc"
    68/push  _test-slice-data-3/imm32/end
    68/push  _test-slice-data-0/imm32/start
    89/copy                         3/mod/direct    1/rm32/ECX    .           .             .           4/r32/ESP   .               .                 # copy ESP to ECX
    # write-slice(_test-buffered-file, slice)
    # . . push args
    51/push-ECX
    68/push  _test-buffered-file/imm32
    # . . call
    e8/call  write-slice/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # flush(_test-buffered-file)
    # . . push args
    68/push  _test-buffered-file/imm32
    # . . call
    e8/call  flush/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # check-stream-equal(_test-stream, "Abc", msg)
    # . . push args
    68/push  "F - test-write-slice"/imm32
    68/push  "Abc"/imm32
    68/push  _test-stream/imm32
    # . . call
    e8/call  check-stream-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

# write an entire stream's contents to a buffered-file
# ways to do this:
#   - construct a 'maximal slice' and pass it to write-slice
#   - flush the buffered-file and pass the stream directly to its fd (disabling buffering)
# we'll go with the first way for now
write-stream-buffered:  # f : (address buffered-file), s : (address stream) -> <void>
    # . 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
    # ESI = s
    8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .             .           6/r32/ESI   0xc/disp8       .                 # copy *(EBP+12) to ESI
    # var slice/ECX = {s->data, s->data + s->write}
    # . push s->data + s->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
    50/push-EAX
    # . push s->data
    8d/copy-address                 1/mod/*+disp8   6/rm32/ESI    .           .             .           0/r32/EAX   0xc/disp8       .                 # copy ESI+12 to EAX
    50/push-EAX
    # . ECX = ESP
    89/copy                         3/mod/direct    1/rm32/ECX    .           .             .           4/r32/ESP   .               .                 # copy ESP to ECX
    # write-slice(f, slice)
    # . . push args
    51/push-ECX
    ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           8/disp8         .                 # push *(EBP+8)
    # . . call
    e8/call  write-slice/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
$write-stream-buffered:end:
    # . restore locals
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # . restore registers
    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-write-stream-buffered:
    # . 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
    # . clear-stream(_test-buffered-file+4)
    # . . push args
    b8/copy-to-EAX  _test-buffered-file/imm32
    05/add-to-EAX  4/imm32
    50/push-EAX
    # . . call
    e8/call  clear-stream/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # . clear-stream(_test-tmp-stream)
    # . . push args
    68/push  _test-tmp-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
    # initialize input
    # . write(_test-tmp-stream, "abcd")
    # . . push args
    68/push  "abcd"/imm32
    68/push  _test-tmp-stream/imm32
    # . . call
    e8/call  write/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # perform the write-stream-buffered
    # . write-stream-buffered(_test-buffered-file, _test-tmp-stream)
    # . . push args
    68/push  _test-tmp-stream/imm32
    68/push  _test-buffered-file/imm32
    # . . call
    e8/call  write-stream-buffered/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
    # check that the write happened as expected
    # . flush(_test-buffered-file)
    # . . push args
    68/push  _test-buffered-file/imm32
    # . . call
    e8/call  flush/disp32
    # . . discard args
    81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
    # . check-stream-equal(_test-stream, "abcd", msg)
    # . . push args
    68/push  "F - test-write-stream-buffered"/imm32
    68/push  "abcd"/imm32
    68/push  _test-stream/imm32
    # . . call
    e8/call  check-stream-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

_test-slice-data-0:
    41/A
_test-slice-data-1:
    62/b
_test-slice-data-2:
    63/c
_test-slice-data-3:
    64/d
_test-slice-data-4:

# . _. vim:nowrap:textwidth=0