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Very fast split string to array function
Posted: Fri Sep 24, 2004 1:15 pm
by wilbert
Here's a small lib I wrote (it only contains 1 function) to split a string into an array. Just download the zip file and extract it into the PB UserLibraries folder. On my computer it splits a 64KB string within a few msec.
It works like this...
Code: Select all
Dim MyArray.s(0)
MyString.s = "This is the string to split."
MyArray() = SplitStringByChar(MyString, " .,", #True, MyArray())
If MyArray()
MyArrayLength = PeekL(MyArray()-8)
Debug MyArrayLength
EndIf
As you can see, it has 4 parameters.
- The first one is the string to split
- The second one the chars (max 8 chars) to split on
- The third one is #True or #False. If #True, empty strings are skipped on output
- The fourth one the array. This is required to free the array before creating the new one
https://w73.nl/pb/split.zip
Enjoy...
Posted: Fri Sep 24, 2004 1:30 pm
by Dare2
This is useful.
Many thanks.
Posted: Fri Sep 24, 2004 11:52 pm
by swan
Just the ticket. Thanx. Very useful.
SWAN ...
Posted: Sat Sep 25, 2004 3:47 pm
by wilbert
Thanks for the feedback
I updated the lib to include also a fast function to combine an array of strings into a single string. Make sure your stringbuffer is large enough to combine the array into a string (by default it is 64000 bytes).
Code: Select all
Dim MyArray.s(0)
MyString.s = "This is the string to split."
MyArray() = SplitStringByChar(MyString, " .,", #True, MyArray())
If MyArray()
MyArrayLength = PeekL(MyArray()-8)
MyRecombinedArray.s = CombineStringArray(MyArray(), "|")
Debug MyRecombinedArray
EndIf
Here's a little speed test
Code: Select all
; free the old string buffer
! pushd [_PB_StringBase]
! pushd 0
! pushd [_PB_MemoryBase]
! call _HeapFree@12
; allocate a new string buffer of 260KB
! pushd 266240
! pushd 8
! pushd [_PB_MemoryBase]
! call _HeapAlloc@12
! mov [_PB_StringBase],eax
; create an array with 16384 16 byte strings making a total size of 256KB
Dim a.s(16383)
Dim b.s(0)
For i=0 To 16383
a(i) = "1234567890ABCDEF"
Next
Delay(500)
; let's measure how long it takes to combine them into a string
timer0 = GetTickCount_()
s.s = CombineStringArray(a(),"")
; now let's measure how long it takes to split this string into another array
; we'll use two separators so the created array will have 32769 items
timer1 = GetTickCount_()
b() = SplitStringByChar(s, "4D", #False, b())
timer2 = GetTickCount_()
result.s = "Combining 16384 items into a 256KB string took "+Str(timer1-timer0)+" ms"+Chr(13)+Chr(10)+"Splitting this string with two separators into an array with 32769 items took "+Str(timer2-timer1)+" ms"
MessageRequester("Results",result.s,0)
If you have a fast computer the speed of this test may be hard to measure. Just to give you an idea I increased the values on my computer (athlon xp 1600+) a bit. Combining 262144 items into a 4 megabyte string took 60 ms and splitting this 4MB string with two separators in an array with 524289 items took 80 ms. 
Re: Very fast split string to array function
Posted: Sat Sep 25, 2004 9:51 pm
by NoahPhense
Very nice function. You should include your example with your zip.
- np
Posted: Sun Sep 26, 2004 8:22 am
by wilbert
I added them to my regular library with some documentation and a small example.
www.geboortegrond.nl/pb/wb_Lib.zip
Also I added a prefix to the functions to avoid possible problems with other libraries.
Posted: Sun Sep 26, 2004 1:21 pm
by NoahPhense
wilbert wrote:I added them to my regular library with some documentation and a small example.
www.geboortegrond.nl/pb/wb_Lib.zip
Also I added a prefix to the functions to avoid possible problems with other libraries.
Good help file, and nice naming conventions.
- np
Posted: Mon Sep 27, 2004 2:18 pm
by wilbert
NoahPhense wrote:Good help file, and nice naming conventions.
Thanks.
I was wondering what other array functions are considered to be useful.
Posted: Mon Sep 27, 2004 2:58 pm
by Dare2
Hi Wilbert.
That is a very nifty library.
Would it be too hard to get ubound(x) where x is the dimension in a multi-dimensioned array, eg, dim(x,y,z) - ubound(0), ubound(1), ubound(2)?
I recall discovering what appeared to be the total element size at a negative offset of the array address, but never discovering the dimension info.
Not very important, BTW. So if you have a rainy day ...
Again, props on that lib.
(OT: BTW, both you and J. Baker are KoolMovers, are you not?)
Posted: Mon Sep 27, 2004 4:07 pm
by wilbert
Dare2 wrote:Would it be too hard to get ubound(x) where x is the dimension in a multi-dimensioned array, eg, dim(x,y,z) - ubound(0), ubound(1), ubound(2)?
Unfortunately yes.
PB does store these values but as far as I know there's no way to determine if it is a multidimensional array. The functions I created assume a single dimensional array.
Another problem is that these dimensions are stored after the pointer to the array but I haven't found a way to pass this pointer to a function.
What you can do if you know the name of your array is this
Code: Select all
Global tmp1, tmp2, tmp3, tmp4
Dim myArray.l(40,5,6,7)
! mov eax,[a_myArray]
! pushd [eax-8]
! popd [v_tmp1]
! pushd [a_myArray + 4]
! popd [v_tmp2]
! pushd [a_myArray + 8]
! popd [v_tmp3]
! pushd [a_myArray + 12]
! popd [v_tmp4]
ubound1 = tmp1 / tmp2 - 1
ubound2 = tmp2 / tmp3 - 1
ubound3 = tmp3 / tmp4 - 1
ubound4 = tmp4 - 1
Debug ubound1
Debug ubound2
Debug ubound3
Debug ubound4
But that's not very convenient
About your BTW... yes, we are both KoolMovers
(great application)
Posted: Sat Oct 30, 2004 6:32 pm
by Shannara
Any way to update this library for PB 3.92? Right now it crashes when being used.
Posted: Sat Oct 30, 2004 6:37 pm
by wilbert
Can you tell me what functions make it crash or give an example ?
When I tried my examples in 3.92 they worked fine
Posted: Sat Oct 30, 2004 6:43 pm
by Shannara
Sorry
It was another piece of code, tried to come back and erase my post, only to find out that you already replied
please disreguard my post.
Posted: Tue Dec 21, 2004 10:30 pm
by dracflamloc
Awesome I've been wanting this =)
Does this only work with windows?
Posted: Wed Dec 22, 2004 11:52 am
by wilbert
dracflamloc wrote:Does this only work with windows?
Yes.
Since it's all x86 asm I think it shouldn't be difficult to make a linux version but my knowledge of linux is very little.