A trivial but useful routine to return the Field offset of a string in a reference string.
RichardL
Code: Select all
Procedure FindField(String$,Search$,Sep$,CaseFlag=0)
; R1 (1747 mSec / 1 000 000
; Un-suitable for cases when Search$ may be a substring in a reference String field
; ASCII Only.
; Return the field number for 'Search$' in the longer string 'String$'
; employing separators 'Sep$'.
; Default is to case independent search. Set flag 'True' to match cases.
If FindString(Search$,Sep$)
MessageRequester("ERROR: FindField()","'Search$' cannot include 'Sep$'")
ProcedureReturn 0
EndIf
; Case independent match.
If CaseFlag = 0
String$ = UCase(String$)
Search$ = UCase(Search$)
EndIf
; Find match in string
p = FindString(String$,Search$)
; Find corresponding field number
If p
p = CountString(Left(String$,p),Sep$)
ProcedureReturn p + 1
Else
ProcedureReturn 0
EndIf
EndProcedure
Procedure R2FindField(String$,Search$,Sep$,CaseFlag=0)
; R2 (2527 mSec / 1 000 000)
; Fixes the defect in R1
; ASCII only.
; Return the field number for 'Search$' in the longer string 'String$'
; employing separators 'Sep$'.
; Default is to case independent search. Set CaseFlag 'True' to match cases.
Protected n
If FindString(Search$,Sep$)
MessageRequester("ERROR: FindField()","'Search$' cannot include 'Sep$'")
ProcedureReturn 0
EndIf
; Case independent match...
If CaseFlag = 0
String$ = UCase(String$)
Search$ = UCase(Search$)
EndIf
; Compare fields
For n = 1 To CountString(String$,Sep$) + 1
If StringField(String$,n,Sep$) = Search$
ProcedureReturn n
EndIf
Next
ProcedureReturn 0
EndProcedure
Procedure R3FindField(String$,Find$,Sep$,CaseFlag=0)
; R3 (1601 mSec / 1 000 000) - Single scan method. More code, but faster
; ASCII only.
; Return the field number for 'Search$' in the longer string 'String$'
; employing separators 'Sep$'.
; Default is to case independent search. Set CaseFlag 'True' to match cases.
Protected *FK = @Find$ ; String to find Ex: DICK
Protected SepC = PeekC(@Sep$) ; Separator Ex: |
Protected Result = 0
Protected FieldCount = 0
Protected LF = Len(Find$)
Protected MCount = 0
Protected *F = *FK-1
Protected *S = @String$ -1 ; Reference string Ex: Tom|Dick|Harry|
If FindString(Find$,Sep$)
MessageRequester("ERROR: FindField()","'Find$' cannot include 'Sep$'")
ProcedureReturn 0
EndIf
Repeat
; Advance pointers and get chars from Ref and Find strings
*F + 1 : F = PeekC(*F)
*S + 1 : C = PeekC(*S)
; End of BOTH fields, and they match!
If (C = SepC Or C = 0) And F = 0 And MCount=LF
Result = FieldCount + 1
Break
EndIf
; Reached end of Ref string so finish
If C = 0
Break
EndIf
; Reached end of REF field, prepare for next one
If C = SepC ; Ref field end
FieldCount + 1
*F = *FK-1 ; Re-start Find
MCount = 0
Continue
EndIf
; Reached end of FIND field, run over remaining REF chars
If F = 0
While PeekC(*S) <> SepC And PeekC(*S) <> 0 : *S+ 1 : Wend
*S - 1
*F = *FK-1 ; Re-start Find
MCount = 0
Continue
EndIf
; Compare field chars and count matching chars
If Not CaseFlag ; Case independent, so move 'a-z' to 'A-Z'
If C >= 'a' And C <= 'z' : C - 32 : EndIf
If F >= 'a' And F <= 'z' : F - 32 : EndIf
EndIf
If C = F
MCount + 1
Else
While PeekC(*S) <> SepC And PeekC(*S) <> 0 : *S+ 1 : Wend
*S - 1
*F = *FK-1
MCount = 0
EndIf
ForEver
ProcedureReturn Result
EndProcedure
TestCount = 100000
TS = ElapsedMilliseconds()
For n = 1 To TestCount
T = FindField("the|cat|sat|On the |mat","on the ","|",1) ; 0 1
T + FindField("the|cat|sat|on the |mat|","COW","|") ; 0 2
T + FindField("the|cat|sat|on the |mat|","LONGCOW","|") ; 0 3
T + FindField("the |cat|sat|on the |mat","the ","|") ; 1 4
T + FindField("cat","CAT","|") ; 1 5
T + FindField("the|CAT|sat|On the |mat","CAT","|") ; 2 6
T + FindField("the|CAT|sat|On the |mat","SAT","|") ; 3 7
T + FindField("these|cats|sat|on the |at","on the ","|") ; 4 8
T + FindField("mon|tue|wed|thu|fri|sat|sun","Fri","|") ; 5 9
T + FindField("the,name,of this,tomcat,is,tom,", "TOM", ",") ; 6 10
; ====
; 22
If TestCount = 1
T + FindField("the|cat|sat|on|the|mat","Bang|","|") ; ERROR and 0
If T <> 22 : MessageRequester("Error","Sort it...") : EndIf
EndIf
Next
MessageRequester("Timer... 1M tests",Str(10*(n-1))+ " Tests in "+Str(ElapsedMilliseconds()-TS)+" mSec")
;http://www.youtube.com/watch?v=27ugSKW4-QQ
