AutoHotkey Community

/*
Demo illustrating the use of Bit Flags
with a special thanks to Laszlo for sharing
his short and sweet little technique for the
retrieval of Bit Flags (which I've used here).

Variables used:
x = The variable we're going to set and reset the bits in
s = The variable containing the Bit to be Set or Reset
msg = Bit Status Report
var = temporary variable used by the set and reset functions
bit = temporary variable used by the set and reset functions
ds = Gui 1 Variable
dr = Gui 2 Variable

Hotkeys:
F8 = Set a Bit and Display the Bit Table
F9 = Reset a Bit and Display the Bit Table
F10 = Display the Bit Table
*/

x = 0
F8::
s = 0
s = Exit
Gui,1:Destroy
List1= Exit||0|1|2|3|4|5|6|7|8|9|10|11|12|13|14|15
Gui, 1: Font, Arial S11
Gui, 1: Add, Text, x9 y7 w112 h30 , Select Bit to Set
Gui, 1: Add, DropDownList, x32 y35 w50 h310 vds gF8D, %List1%
Gui, 1: Show, center h360 w112, Select
sendinput, !{up}
return

F8D:
Gui, 1: Submit
Gui,1:Destroy
s = %ds%
If s != Exit
   goto, F8C
Return

1GuiEscape:
1GuiClose:
exitapp

F8C:
if (s = "Exit")
   return
x := set(x,s)  ; Set the Bit
msg =
Loop, 16  ; Generate the Status Report
{
If A_Index < 11
  msg .= "Bit  " . A_Index -1 . " :  " .  x>>(A_Index-1) & 1 . "           ( " . 2**(A_Index - 1) . " )`n"
else
  msg .= "Bit " . A_Index -1 . " : " .  x>>(A_Index-1) & 1 . "           ( " . 2**(A_Index - 1) . " )`n"
}
msg := "Bit   Status   Weighted Value`n`n" . msg
MsgBox, 0, Current Bit Status,%msg%`nx = %x%
return

F9::
s = 0
s = Exit
Gui,2:Destroy
List1= Exit||0|1|2|3|4|5|6|7|8|9|10|11|12|13|14|15
Gui, 2: Font, Arial S11
Gui, 2: Add, Text, x6 y7 w112 h30 , Select Bit to Reset
Gui, 2: Add, DropDownList, x37 y35 w50 h310 vdr gF9D, %List1%
Gui, 2: Show, center h365 w122, Select
sendinput, !{up}
return

F9D:
Gui, 2: Submit
Gui,2:Destroy
s = %dr%
If s != Exit
   goto, F9C
Return

2GuiEscape:
2GuiClose:
exitapp

F9C:
if (s = "Exit")
   return
x := reset(x,s)  ; Reset the Bit
msg =
Loop, 16  ; Generate the Status Report
{
If A_Index < 11
  msg .= "Bit  " . A_Index -1 . " :  " .  x>>(A_Index-1) & 1 . "           ( " . 2**(A_Index - 1) . " )`n"
else
  msg .= "Bit " . A_Index -1 . " : " .  x>>(A_Index-1) & 1 . "           ( " . 2**(A_Index - 1) . " )`n"
}
msg := "Bit   Status   Weighted Value`n`n" . msg
MsgBox, 0, Current Bit Status,%msg%`nx = %x%
return

F10::  ; Display Bit Status
msg =
Loop, 16  ; Generate the Status Report
{
If A_Index < 11
  msg .= "Bit  " . A_Index -1 . " :  " .  x>>(A_Index-1) & 1 . "           ( " . 2**(A_Index - 1) . " )`n"
else
  msg .= "Bit " . A_Index -1 . " : " .  x>>(A_Index-1) & 1 . "           ( " . 2**(A_Index - 1) . " )`n"
}
msg := "Bit   Status   Weighted Value`n`n" . msg
MsgBox, 0, Current Bit Status,%msg%`nx = %x%
return

; Set a Bit (if it's not set) by adding the appropriate power of 2 to the variable
set(var,bit) {
return (var += ((var>>bit) & 1) = 0 ? 2**bit  : 0)
}

; Reset a Bit (if it's set) by subtracting the appropriate power of 2 from the variable
reset(var,bit) {
return (var -= ((var>>bit) & 1) = 1 ? 2**bit  : 0)
}

; fun with bits
; (w) by derRaphael 2010-03-07

d:=0, bits := 8

loop, % bits
{
   setFlag( d, a_index )
   msgbox,0,% "flagged Index: " a_index,  % d2b(d)
}   

loop, % bits
{
   delFlag( d, a_index )
   msgbox,0,% "removed flag on index: " a_index,  % d2b(d)
}   

loop, % bits
{
   if ! ( A_Index & 1 )
      setFlag( d, A_Index )
}

MsgBox,0, All even Flags Set, % d2b(d)

; toggle flags one by one
Loop, % bits
{
   tglFlag( d, a_index )
}

MsgBox,0, All Flags Inverted, % d2b(d)

; this toggles all flags instantly, but d becomes an inverted 32bit value
; which it has been before, too ;)
d := ~d
msgbox,0,% "literal value of d: " d, % "Binary representation: " d2b(d,32)

; functions

; sets a flag at a specified index
setFlag( byref d, flagIdx )
{
   d |= ( 2**(flagIdx-1) )
}

; deletes a flag at a specified index
delFlag( byref d, flagIdx )
{
   if ( isFlag( d, flagIdx ) )
      tglFlag( d, flagIdx )
}

; toggles a flag at a specified index
tglFlag( byref d, flagIdx )
{
   d ^= ( 2**(flagIdx-1) )
}

; returns true if flag is set at a specified index
isFlag( byRef d, flagIdx )
{
   return d && ( 2**(flagIdx-1) )
}

; converts a decimal to a binary representation showing all bits
d2b( dec, bits=8 )
{
   loop,% bits
   {
      out .= ( dec >> (bits-a_index) ) & 1
   }
   return out
}

a := 123456
b := 654321

msgbox % a "/" b
swap(a,b)
msgbox % a "/" b

; short and sweet, interesting cuz it avoids the need for temp vars
swap(byref a, byref b)
{
   a^=b, b^=a, a^=b
}

Swap(ByRef Left, ByRef Right) {
    Left := (Right "", Right := Left) ; value of list is leftmost expr, terms are executed from left to right
}