I think the main risk I've seen using variants and implicit conversion is in comparisons. When I was new to AutoIt3 I got some strange results in comparisons because I didn't realize that reading a value from an .ini file produced a string, no matter the value. Ini files often use 0 for False and 1 for True. It was easy when typing in code to make the error demonstrated by the top half of the code below(esp. since in .ini files strings are not quoted. Easy to see it as boolean instead of string.) That's why I came up with _IniBool() function. It seems trivial but with it you can actually use Boolean values in AutoIt variables and True or False will be written to the .ini using IniWrite. If the user changes it to 1 for true and 0 for false, it still functions as expected.
$val = "1"
If $val Then
MsgBox(0x1040,"test","$val is True" & " " & $val)
Else
MsgBox(0x1040,"test","$val is False" & " " & $val)
EndIf
$val = "0"
If $val Then
MsgBox(0x1040,"test","$val is True" & " " & $val)
Else
MsgBox(0x1040,"test","$val is False" & " " & $val)
EndIf
$val = "1"
If _IniBool($val) Then
MsgBox(0x1040,"test","$val is True" & " " & $val)
Else
MsgBox(0x1040,"test","$val is False" & " " & $val)
EndIf
$val = "0"
If _IniBool($val) Then
MsgBox(0x1040,"test","$val is True" & " " & $val)
Else
MsgBox(0x1040,"test","$val is False" & " " & $val)
EndIf
Func _IniBool($val)
If $val = "True" Or $val = "1" Then Return True
Return False
EndFunc ;==>_IniBool
For the AHK_L code in question this demonstrates that one can stick the result of SubStr() in another dedicated variable. But since there's no comparison it's just the creation of another variable for no real reason. I found out from Lexicos the author of AHK_L when you create a variable, even a local in a function, the storage is there for the life of the program run. He stressed the main danger of doing things like myObject := 0 to clear an object is if you have other references to the same object. In that case you can get side effects/unexpected behavior. For that reason I modified a small utility I wrote to create an object as a local inside a function, then return the result out to the global. Lexicos says that even though the local variables don't "disappear" when the function returns like compiled program stack variables, the storage is reused on the next function call. So basically, if I make sure I only see one reference to an object, I can safely clear its contents with myObject := 0. In which case the variable myObject is now a numeric. But then you can just assign the object returned from the function and its type is restored to Object.
Fun stuff. Here's a link to the discussion where I asked about just setting an object to 0 to clear the contents. The link is pretty much the climax of the topic.
http://www.autohotke...amp;start=15#p544146Here's ahk sticking the result of SubStr() in a different variable
mySerial := 1
myFactor := 2
myTemp := 0
^g:: ; Ctrl+G, change to whatever you want.
{
;mySerial := SubStr("000000" . mySerial, -5)
myTemp := SubStr("000000" . mySerial, -5)
SendInput, % myTemp
mySerial += myFactor
}
Return
It works. But in this case since I never compare myTemp or mySerial to anything, there's no purpose served.
I also do C#. It's a strongly typed scripting language as opposed to scripting such as AutoIt3 and AHK where they just use Variants for everything. One benefit of the "one size fits all" Variant is that it makes it easy to interface to system scripting stuff that's all IDispatch based.
In any case, I never held a job with "developer" or "programmer" as the job title. But I've been programming in various languages steadily since I first got hooked in 1986. I guess it just seemed pointless to me and a bit insulting to be offered tips on correct programming practice by someone who doesn't even understand the language in question. It would be like me lecturing someone by saying "I don't know a damn thing about Lisp but if I was doing it in Pascal I sure wouldn't do what you're doing there buddy!" heh heh
Generally I find it better to ask for working code than argue. If someone can demonstrate what they claim, and I can run i and see their point, the argument is over pretty quickly. Otherwise it tends to degenerate into who claims to have the highest IQ.
Recent Posts
