Page 1 of 1
Trim function
Posted: Tue May 21, 2024 5:39 pm
by Michael Vogel
Needed a trim function for multiple chars allowing case insensitive matches as well.
Here's the result, which could be easily tuned by using a predefined array to speedup the Ucase(Chr()) part...
Code: Select all
#CharMult= #PB_Compiler_Unicode
#CharByte= #CharMult+1
Procedure.s StrTrim(*s.Character,*trim.Character,DoCase=#True)
Protected *c.Character
Protected *l.Character
Protected *r.Character
Protected mode;char,chck
Debug "----------------------------------------------------"
Debug "Remove '"+PeekS(*trim)+"' with"+Left("out",1!DoCase*3)+" case:"
*l=*s
While *s\c
*c=*trim
If DoCase
While *c\c
If *s\c=*c\c
mode+1
Break
EndIf
*c+#CharByte
Wend
Else
While *c\c
If UCase(Chr(*s\c))=UCase(Chr(*c\c)); see text
mode+1
Break
EndIf
*c+#CharByte
Wend
EndIf
*s+#CharByte
Select mode
Case 0;
mode=4;
*r=*s
Case 1,3;
mode=2
*l=*s
Case 2,4;
mode=4;
*r=*s;
Case 5
mode=4;
EndSelect
Wend
If *r<*l; mode=2
ProcedureReturn ""
EndIf
ProcedureReturn PeekS(*l,(*r-*l)>>#CharMult)
EndProcedure
s.s="****Purebasic is pure****"
Debug s
Debug StrTrim(@s,@"*")
Debug StrTrim(@s,@"*pure")
Debug StrTrim(@s,@"*PURE")
Debug StrTrim(@s,@"*PURE",#Null)
Re: Trim function
Posted: Tue May 21, 2024 11:03 pm
by idle
Think there's still an edge case, it removed the "*P" or is that the intended result?
----------------------------------------------------
Remove '*PURE' with case:
urebasic is pure
----------------------------------------------------
Re: Trim function
Posted: Wed May 22, 2024 1:20 am
by Demivec
idle wrote: Tue May 21, 2024 11:03 pm
Think there's still an edge case, it removed the "*P" or is that the intended result?
----------------------------------------------------
Remove '*PURE' with case:
urebasic is pure
----------------------------------------------------
It's intentional. It trims any of the trim string's characters, in any order, from the beginning or end of the string. It stops when it encounters any character not in the trim string.
Re: Trim function
Posted: Wed May 22, 2024 1:49 am
by idle
Demivec wrote: Wed May 22, 2024 1:20 am
It's intentional. It trims any of the trim string's characters, in any order, from the beginning or end of the string. It stops when it encounters any character not in the trim string.
Makes sense with your explanation.
Re: Trim function
Posted: Wed May 22, 2024 3:52 am
by jassing
Interesting approach, I had a similar need, but I used regex, which appeared about 30% faster...
Code: Select all
DisableDebugger
xincludeFile "StrTrim.pbi"
#iter = 100000
s.s="****Purebasic is pure****"
Define.s s1,s2,s3,s4
EnableDebugger
debug s
Debug StrTrim(@s,@"*")
Debug StrTrim(@s,@"*pure")
Debug StrTrim(@s,@"*PURE")
Debug StrTrim(@s,@"*PURE",#Null)
DisableDebugger
st = ElapsedMilliseconds()
For x = 1 To #iter
s1=StrTrim(@s,@"*")
s2=StrTrim(@s,@"*pure")
s3=StrTrim(@s,@"*PURE")
s4=StrTrim(@s,@"*PURE",#Null)
Next
EnableDebugger
Debug "Strtrim() "+Str(ElapsedMilliseconds()-st)
Debug s
Debug s1
Debug s2
Debug s3
Debug s4
DisableDebugger
Procedure.s megaTrim( *string.Character, *filterChars.Character, bCaseSpecific=#True )
Protected Dim result.s(0)
Protected flags,newString.s,r;
If Not bCaseSpecific : flags = #PB_RegularExpression_NoCase : EndIf
r=CreateRegularExpression( #PB_Any, "[^"+PeekS(*filterChars)+"].*[^"+PeekS(*filterChars)+"]",flags )
If r
If ExtractRegularExpression( r, PeekS(*string), result() )
newString=result(0)
EndIf
FreeRegularExpression(r)
EndIf
ProcedureReturn newString
EndProcedure
Debug s
Debug megaTrim(@s,@"*")
Debug megaTrim(@s,@"*pure")
Debug megaTrim(@s,@"*PURE")
Debug megaTrim(@s,@"*PURE",#False)
DisableDebugger
st=ElapsedMilliseconds()
For x = 1 To #iter
s1=megaTrim(@s,@"*")
s2=megaTrim(@s,@"*pure")
s3=megaTrim(@s,@"*PURE")
s4=megaTrim(@s,@"*PURE",#False)
Next
EnableDebugger
Debug "maxTrim() "+Str(ElapsedMilliseconds()-st)
Debug s
Debug s1
Debug s2
Debug s3
Debug s4
Re: Trim function
Posted: Wed May 22, 2024 4:21 am
by AZJIO
jassing wrote: Wed May 22, 2024 3:52 am
Interesting approach, I had a similar need, but I used regex, which appeared about 30% faster...
string operations are slow
try comparing case sensitive
RTrimChar
Maybe it will be faster this way
Code: Select all
tmp$ = "*PURE"
tmp$ = LCase(tmp$) + UCase(tmp$)
s4=megaTrim(@s,@tmp$,#False)
Re: Trim function
Posted: Thu May 23, 2024 4:02 pm
by Piero
I know you will think I'm an idiot, but it amazes me to read good programmers discussing "30% faster" ways to trim multiple chars in 2024
Where are the """AI""" compilers?
Re: Trim function
Posted: Thu May 23, 2024 5:46 pm
by AZJIO
Piero wrote: Thu May 23, 2024 4:02 pm
Where are the """AI""" compilers?
AI invented to control the AI sect
Re: Trim function
Posted: Thu May 23, 2024 8:21 pm
by jassing
Piero wrote: Thu May 23, 2024 4:02 pm
I know you will think I'm an idiot, but it amazes me to read good programmers discussing "30% faster" ways to trim multiple chars in 2024
It wasn't so much a comment on how fast my version was, but the fact that regex was faster than a custom string-by-reference, which should be faster.
But... as for 30% faster, when you're working with millions of records in a database, 30% can be the difference between an hour or 20 minutes. For human interaction, 300ms vs 100ms isn't noticeable.
Re: Trim function
Posted: Sun May 26, 2024 8:30 pm
by Piero
AZJIO wrote: Thu May 23, 2024 5:46 pm
AI invented to control the AI sect
The big-database sect; when you are stupid and think you can win by cheating, like reading stuff written on your hand during an exam