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String Characters & PB_COMPILER_UNICODE (Ascii/Unicode)
Posted: Wed Sep 27, 2006 9:07 pm
by Xombie
Code updated For 5.20+
Here's something that I just recently noticed and started using. Probably obvious to other people but... well... I'm slow.
Anyway, in the past if I was writing a routine to scan through a string and needed it to be compatible with ascii and unicode, I'd do some compiler-if statements for incrementing the string pointer, getting the character index, etc...
However, you can use bit-shifting to be more lazy
Code: Select all
Structure CHAR
c.c
EndStructure
;-
Procedure.l FindDash(Text.s)
;
Define.l HoldIndex
;
Define.CHAR *HoldChar = @Text
;
While *HoldChar\c <> '-' And *HoldChar\c
;
*HoldChar + (1 << #PB_COMPILER_UNICODE)
;
Wend
;
HoldIndex = ((*HoldChar - @Text) >> #PB_COMPILER_UNICODE) + 1
;
ProcedureReturn HoldIndex
;
EndProcedure
;-
Debug FindDash("Please - test this string.")
;-
End
;-
Like that. Try it under both unicode & non-unicode to see what I mean.
..: Edit :.. Fixed a misplaced addition
Posted: Wed Sep 27, 2006 11:42 pm
by srod
There's nowt wrong with being lazy on occasion!
A neat trick; although SizeOf(CHARACTER) would probably function aswell - maybe not as fast though.
Posted: Thu Sep 28, 2006 3:54 am
by Rescator
Here is a nice "helper" for unicode and ascii.
Code: Select all
CompilerIf #PB_Compiler_Unicode
#Char=2
CompilerElse
#Char=1
CompilerEndIf
Debug #Char
Re: String Characters & PB_COMPILER_UNICODE (Ascii/Unico
Posted: Thu Sep 28, 2006 8:26 am
by horst
@Xombie:
No need to define a structure. With *pointer.character you can use *pointer\c
The character handling by pointer becomes interesting, when you use the pointer in your procedures where several character operations are necessary. Then you can use macros such as:
Code: Select all
Macro StepChar(pointer)
pointer + SizeOf(pointer#\c)
EndMacro
Macro SkipSpace(pointer)
While pointer#\c = ' ' : StepChar(pointer) : Wend
EndMacro
Macro GotoChar(pointer,char)
While pointer#\c
If pointer#\c = char : Break : Endif
StepChar(pointer)
Wend
EndMacro
Example:
Code: Select all
string$ = "1234567890"
*string.character = @string$
GoChar(*string,'7')
*string +1
Debug Chr(*string\c)
Posted: Thu Sep 28, 2006 8:17 pm
by Fred
SizeOf(Character) is definitely the way to go, instead of the 1 << #PB_Compiler_Unicode trick (nice one BTW
)
Posted: Thu Sep 28, 2006 9:42 pm
by Xombie
Thanks, fred
I know about SizeOf() for the char type and I think it'd work fine for incrementing and in order searches but what about getting a character at a specific index without actually looping through the string? That's why I originally figured on the #PB_Compiler_Unicode. It's either 0 for ascii or 1 for unicode. With the '1' you can bit shift left or right to divide or multiply by 2 to get the proper position in a unicode string. And for ascii, bitshifting left or right by 0 does nothing so it has no effect and the byte is the index.
Also, the nicely different colored #PB_Compiler_Unicode (at least in Japbe) lets you know that you're messing with ascii/unicode and you can use it multiple times in a line as needed.
Just my two cents
At the very least it's much less cumbersome than what I was doing with the compiler-if-else-endif.
Posted: Thu Sep 28, 2006 10:06 pm
by Fred
Just use: pos*SizeOf(Character), as if SizeOf() is 1, nothing will be done (PB will remove this useless multiply) and if SizeOf() is 2 it will go to the right place
.