Hello,
I call a function recursively to find an item that exists *anywhere* down
the chain. Let's say I find it five layers deep. Now I've got what I need and
want to break out of that whole stack and continue execution at the point of
the initial call. Is that possible?
Thanks,
Bill 9 12766
Do you mean skip the whole call stack? If that's the case, then AFAIK, you
can't do that. You'll have to follow the call stack back to the point of the
initial call. I believe the reason for this is the for each call to the
recursive method, the current stack frame within the runtime stack has a
pointer only to the previous stack frame from which this call was initiated
and knows nothing about any stack frames before that. As soon as the current
call returns, it returns to the address of the previous stack frame from
which this call was made.
hope that helps..
Imran.
"Bill Borg" <Bi******@discussions.microsoft.com> wrote in message
news:5E**********************************@microsof t.com... Hello,
I call a function recursively to find an item that exists *anywhere* down the chain. Let's say I find it five layers deep. Now I've got what I need
and want to break out of that whole stack and continue execution at the point
of the initial call. Is that possible?
Thanks,
Bill
Bill,
Normally I have the function return a "found" indicator (a Boolean), when I
call it recursively if I find the item I exit the current item.
Something like
Public Function RecusiveFind(value As Object, theCurrentLevel) As
Boolean
For Each item In theCurrentLevel
If item = value Then Return True
If RecusiveFind(value, item.Children) Then Return True
' keep looking at the current level
Next
Return False
End Function
"Bill Borg" <Bi******@discussions.microsoft.com> wrote in message
news:5E**********************************@microsof t.com... Hello,
I call a function recursively to find an item that exists *anywhere* down the chain. Let's say I find it five layers deep. Now I've got what I need and want to break out of that whole stack and continue execution at the point of the initial call. Is that possible?
Thanks,
Bill
Hi Imran,
You can add a global variable. Set it equal to False. Once you hit your
finish point set it to True and Exit Function. Then in the function,
directly after where it calls itself check this variable. If it is True
then Exit Function which will move you right back up the stack and out.
I've never tried using a static variable. I have no idea if that would
work, hmmmm I'll have to try it. Good luck! Ken.
--
Ken Dopierala Jr.
For great ASP.Net web hosting try: http://www.webhost4life.com/default.asp?refid=Spinlight
If you sign up under me and have problems, email me.
"Imran Koradia" <no****@microsoft.com> wrote in message
news:Og*************@TK2MSFTNGP09.phx.gbl... Do you mean skip the whole call stack? If that's the case, then AFAIK, you can't do that. You'll have to follow the call stack back to the point of
the initial call. I believe the reason for this is the for each call to the recursive method, the current stack frame within the runtime stack has a pointer only to the previous stack frame from which this call was
initiated and knows nothing about any stack frames before that. As soon as the
current call returns, it returns to the address of the previous stack frame from which this call was made.
hope that helps.. Imran.
"Bill Borg" <Bi******@discussions.microsoft.com> wrote in message news:5E**********************************@microsof t.com... Hello,
I call a function recursively to find an item that exists *anywhere*
down the chain. Let's say I find it five layers deep. Now I've got what I
need and want to break out of that whole stack and continue execution at the
point of the initial call. Is that possible?
Thanks,
Bill
Why a global variable? Couldn't you just pass your boolean variable as one
of the parameters of the recursive function. In fact, isn't this how you
create a recursive function???
Greg
"Ken Dopierala Jr." <kd*********@wi.rr.com> wrote in message
news:%2****************@TK2MSFTNGP10.phx.gbl... Hi Imran,
You can add a global variable. Set it equal to False. Once you hit your finish point set it to True and Exit Function. Then in the function, directly after where it calls itself check this variable. If it is True then Exit Function which will move you right back up the stack and out. I've never tried using a static variable. I have no idea if that would work, hmmmm I'll have to try it. Good luck! Ken.
-- Ken Dopierala Jr. For great ASP.Net web hosting try: http://www.webhost4life.com/default.asp?refid=Spinlight If you sign up under me and have problems, email me.
"Imran Koradia" <no****@microsoft.com> wrote in message news:Og*************@TK2MSFTNGP09.phx.gbl... Do you mean skip the whole call stack? If that's the case, then AFAIK, you can't do that. You'll have to follow the call stack back to the point of the initial call. I believe the reason for this is the for each call to the recursive method, the current stack frame within the runtime stack has a pointer only to the previous stack frame from which this call was initiated and knows nothing about any stack frames before that. As soon as the current call returns, it returns to the address of the previous stack frame from which this call was made.
hope that helps.. Imran.
"Bill Borg" <Bi******@discussions.microsoft.com> wrote in message news:5E**********************************@microsof t.com... > Hello, > > I call a function recursively to find an item that exists *anywhere* down > the chain. Let's say I find it five layers deep. Now I've got what I need and > want to break out of that whole stack and continue execution at the point of > the initial call. Is that possible? > > Thanks, > > Bill
Right - I understand that. But you're still going to be checking that
variable for each recursive call that you made. Ofcourse, you can avoid the
code after the recursive call within the method. But you're still going to
pass through the entire call stack back to the initial call. There's no way
you can skip the call stack. Or am I missing something?
Imran.
"Ken Dopierala Jr." <kd*********@wi.rr.com> wrote in message
news:%2****************@TK2MSFTNGP10.phx.gbl... Hi Imran,
You can add a global variable. Set it equal to False. Once you hit your finish point set it to True and Exit Function. Then in the function, directly after where it calls itself check this variable. If it is True then Exit Function which will move you right back up the stack and out. I've never tried using a static variable. I have no idea if that would work, hmmmm I'll have to try it. Good luck! Ken.
-- Ken Dopierala Jr. For great ASP.Net web hosting try: http://www.webhost4life.com/default.asp?refid=Spinlight If you sign up under me and have problems, email me.
"Imran Koradia" <no****@microsoft.com> wrote in message news:Og*************@TK2MSFTNGP09.phx.gbl... Do you mean skip the whole call stack? If that's the case, then AFAIK,
you can't do that. You'll have to follow the call stack back to the point of the initial call. I believe the reason for this is the for each call to the recursive method, the current stack frame within the runtime stack has a pointer only to the previous stack frame from which this call was initiated and knows nothing about any stack frames before that. As soon as the current call returns, it returns to the address of the previous stack frame from which this call was made.
hope that helps.. Imran.
"Bill Borg" <Bi******@discussions.microsoft.com> wrote in message news:5E**********************************@microsof t.com... Hello,
I call a function recursively to find an item that exists *anywhere* down the chain. Let's say I find it five layers deep. Now I've got what I
need and want to break out of that whole stack and continue execution at the point of the initial call. Is that possible?
Thanks,
Bill
You could kill the whole stack by throwing an exception :-)
--
Jonathan Bailey.
"Imran Koradia" <no****@microsoft.com> wrote in message
news:eL***************@TK2MSFTNGP10.phx.gbl... Right - I understand that. But you're still going to be checking that variable for each recursive call that you made. Ofcourse, you can avoid
the code after the recursive call within the method. But you're still going to pass through the entire call stack back to the initial call. There's no
way you can skip the call stack. Or am I missing something?
Imran.
"Ken Dopierala Jr." <kd*********@wi.rr.com> wrote in message news:%2****************@TK2MSFTNGP10.phx.gbl... Hi Imran,
You can add a global variable. Set it equal to False. Once you hit
your finish point set it to True and Exit Function. Then in the function, directly after where it calls itself check this variable. If it is True then Exit Function which will move you right back up the stack and out. I've never tried using a static variable. I have no idea if that would work, hmmmm I'll have to try it. Good luck! Ken.
-- Ken Dopierala Jr. For great ASP.Net web hosting try: http://www.webhost4life.com/default.asp?refid=Spinlight If you sign up under me and have problems, email me.
"Imran Koradia" <no****@microsoft.com> wrote in message news:Og*************@TK2MSFTNGP09.phx.gbl... Do you mean skip the whole call stack? If that's the case, then AFAIK, you can't do that. You'll have to follow the call stack back to the point
of the initial call. I believe the reason for this is the for each call to
the recursive method, the current stack frame within the runtime stack has
a pointer only to the previous stack frame from which this call was
initiated and knows nothing about any stack frames before that. As soon as the current call returns, it returns to the address of the previous stack frame
from which this call was made.
hope that helps.. Imran.
"Bill Borg" <Bi******@discussions.microsoft.com> wrote in message news:5E**********************************@microsof t.com... > Hello, > > I call a function recursively to find an item that exists *anywhere* down > the chain. Let's say I find it five layers deep. Now I've got what I need and > want to break out of that whole stack and continue execution at the point of > the initial call. Is that possible? > > Thanks, > > Bill
Well - even when an exception is thrown, the runtime searches up the call
stack to look for an appropriate exception handler which means its still
going to be travelling up the call stack. However, I'm not sure how the
runtime handles exceptions for recursive procedures - is it even aware that
its a recursive call? If so, it could just check once whether the procedure
has an exception handler and if not, it could skip the entire stack sequence
for the recursion and jump right back to the initial calling method. But I
doubt that..I could be wrong though..
Imran.
<jb> wrote in message news:41***********************@news.easynet.co.uk. .. You could kill the whole stack by throwing an exception :-)
-- Jonathan Bailey.
"Imran Koradia" <no****@microsoft.com> wrote in message news:eL***************@TK2MSFTNGP10.phx.gbl... Right - I understand that. But you're still going to be checking that variable for each recursive call that you made. Ofcourse, you can avoid the code after the recursive call within the method. But you're still going
to pass through the entire call stack back to the initial call. There's no way you can skip the call stack. Or am I missing something?
Imran.
"Ken Dopierala Jr." <kd*********@wi.rr.com> wrote in message news:%2****************@TK2MSFTNGP10.phx.gbl... Hi Imran,
You can add a global variable. Set it equal to False. Once you hit your finish point set it to True and Exit Function. Then in the function, directly after where it calls itself check this variable. If it is
True then Exit Function which will move you right back up the stack and
out. I've never tried using a static variable. I have no idea if that
would work, hmmmm I'll have to try it. Good luck! Ken.
-- Ken Dopierala Jr. For great ASP.Net web hosting try: http://www.webhost4life.com/default.asp?refid=Spinlight If you sign up under me and have problems, email me.
"Imran Koradia" <no****@microsoft.com> wrote in message news:Og*************@TK2MSFTNGP09.phx.gbl... > Do you mean skip the whole call stack? If that's the case, then
AFAIK, you > can't do that. You'll have to follow the call stack back to the
point of the > initial call. I believe the reason for this is the for each call to the > recursive method, the current stack frame within the runtime stack
has a > pointer only to the previous stack frame from which this call was initiated > and knows nothing about any stack frames before that. As soon as the current > call returns, it returns to the address of the previous stack frame from > which this call was made. > > hope that helps.. > Imran. > > "Bill Borg" <Bi******@discussions.microsoft.com> wrote in message > news:5E**********************************@microsof t.com... > > Hello, > > > > I call a function recursively to find an item that exists
*anywhere* down > > the chain. Let's say I find it five layers deep. Now I've got what
I need > and > > want to break out of that whole stack and continue execution at
the point > of > > the initial call. Is that possible? > > > > Thanks, > > > > Bill > >
I was joking of course :-)
I cant find in the MS website where exceptions are defined but I expect vb
creates a try,catch block around any function which might throw one which
then passes it to the previous caller.
It just 'looks like' you are skipping up the stack in the source code.
--
Jonathan Bailey.
"Imran Koradia" <no****@microsoft.com> wrote in message
news:%2****************@tk2msftngp13.phx.gbl... Well - even when an exception is thrown, the runtime searches up the call stack to look for an appropriate exception handler which means its still going to be travelling up the call stack. However, I'm not sure how the runtime handles exceptions for recursive procedures - is it even aware
that its a recursive call? If so, it could just check once whether the
procedure has an exception handler and if not, it could skip the entire stack
sequence for the recursion and jump right back to the initial calling method. But I doubt that..I could be wrong though..
Imran.
<jb> wrote in message news:41***********************@news.easynet.co.uk. .. You could kill the whole stack by throwing an exception :-)
-- Jonathan Bailey.
"Imran Koradia" <no****@microsoft.com> wrote in message news:eL***************@TK2MSFTNGP10.phx.gbl... Right - I understand that. But you're still going to be checking that variable for each recursive call that you made. Ofcourse, you can
avoid the code after the recursive call within the method. But you're still
going to pass through the entire call stack back to the initial call. There's
no way you can skip the call stack. Or am I missing something?
Imran.
"Ken Dopierala Jr." <kd*********@wi.rr.com> wrote in message news:%2****************@TK2MSFTNGP10.phx.gbl... > Hi Imran, > > You can add a global variable. Set it equal to False. Once you hit your > finish point set it to True and Exit Function. Then in the
function, > directly after where it calls itself check this variable. If it is True > then Exit Function which will move you right back up the stack and out. > I've never tried using a static variable. I have no idea if that would > work, hmmmm I'll have to try it. Good luck! Ken. > > -- > Ken Dopierala Jr. > For great ASP.Net web hosting try: > http://www.webhost4life.com/default.asp?refid=Spinlight > If you sign up under me and have problems, email me. > > "Imran Koradia" <no****@microsoft.com> wrote in message > news:Og*************@TK2MSFTNGP09.phx.gbl... > > Do you mean skip the whole call stack? If that's the case, then AFAIK, you > > can't do that. You'll have to follow the call stack back to the point of > the > > initial call. I believe the reason for this is the for each call
to the > > recursive method, the current stack frame within the runtime stack has a > > pointer only to the previous stack frame from which this call was > initiated > > and knows nothing about any stack frames before that. As soon as
the > current > > call returns, it returns to the address of the previous stack
frame from > > which this call was made. > > > > hope that helps.. > > Imran. > > > > "Bill Borg" <Bi******@discussions.microsoft.com> wrote in message > > news:5E**********************************@microsof t.com... > > > Hello, > > > > > > I call a function recursively to find an item that exists *anywhere* > down > > > the chain. Let's say I find it five layers deep. Now I've got
what I > need > > and > > > want to break out of that whole stack and continue execution at the > point > > of > > > the initial call. Is that possible? > > > > > > Thanks, > > > > > > Bill > > > > > >
lol :)
yeah - I couldn't find anything either but considering how exception
handling works in java, I bet that's how it works.
Imran.
<jb> wrote in message news:41***********************@news.easynet.co.uk. .. I was joking of course :-) I cant find in the MS website where exceptions are defined but I expect vb creates a try,catch block around any function which might throw one which then passes it to the previous caller. It just 'looks like' you are skipping up the stack in the source code.
-- Jonathan Bailey.
"Imran Koradia" <no****@microsoft.com> wrote in message news:%2****************@tk2msftngp13.phx.gbl... Well - even when an exception is thrown, the runtime searches up the
call stack to look for an appropriate exception handler which means its still going to be travelling up the call stack. However, I'm not sure how the runtime handles exceptions for recursive procedures - is it even aware that its a recursive call? If so, it could just check once whether the procedure has an exception handler and if not, it could skip the entire stack sequence for the recursion and jump right back to the initial calling method. But
I doubt that..I could be wrong though..
Imran.
<jb> wrote in message
news:41***********************@news.easynet.co.uk. .. You could kill the whole stack by throwing an exception :-)
-- Jonathan Bailey.
"Imran Koradia" <no****@microsoft.com> wrote in message news:eL***************@TK2MSFTNGP10.phx.gbl... > Right - I understand that. But you're still going to be checking
that > variable for each recursive call that you made. Ofcourse, you can avoid the > code after the recursive call within the method. But you're still going to > pass through the entire call stack back to the initial call. There's no way > you can skip the call stack. Or am I missing something? > > Imran. > > "Ken Dopierala Jr." <kd*********@wi.rr.com> wrote in message > news:%2****************@TK2MSFTNGP10.phx.gbl... > > Hi Imran, > > > > You can add a global variable. Set it equal to False. Once you
hit your > > finish point set it to True and Exit Function. Then in the function, > > directly after where it calls itself check this variable. If it
is True > > then Exit Function which will move you right back up the stack and out. > > I've never tried using a static variable. I have no idea if that would > > work, hmmmm I'll have to try it. Good luck! Ken. > > > > -- > > Ken Dopierala Jr. > > For great ASP.Net web hosting try: > > http://www.webhost4life.com/default.asp?refid=Spinlight > > If you sign up under me and have problems, email me. > > > > "Imran Koradia" <no****@microsoft.com> wrote in message > > news:Og*************@TK2MSFTNGP09.phx.gbl... > > > Do you mean skip the whole call stack? If that's the case, then AFAIK, > you > > > can't do that. You'll have to follow the call stack back to the point of > > the > > > initial call. I believe the reason for this is the for each call to the > > > recursive method, the current stack frame within the runtime
stack has a > > > pointer only to the previous stack frame from which this call
was > > initiated > > > and knows nothing about any stack frames before that. As soon as
the > > current > > > call returns, it returns to the address of the previous stack frame from > > > which this call was made. > > > > > > hope that helps.. > > > Imran. > > > > > > "Bill Borg" <Bi******@discussions.microsoft.com> wrote in
message > > > news:5E**********************************@microsof t.com... > > > > Hello, > > > > > > > > I call a function recursively to find an item that exists *anywhere* > > down > > > > the chain. Let's say I find it five layers deep. Now I've got what I > > need > > > and > > > > want to break out of that whole stack and continue execution
at the > > point > > > of > > > > the initial call. Is that possible? > > > > > > > > Thanks, > > > > > > > > Bill > > > > > > > > > > > >
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