Need a fancy RegEx

General
1

If anyone can figure this out. it would be Kem :slight_smile:

Given 4 discrete strings (none of the a constant)
Given an Index to a postion in another String (call it source)
return the postion of the first of the 4 string that appear in the source string and which of the 4 strings it was

so for example… if the 4 strings were “A”,“B”,“C”,“D”
and the source string was “WXYZCQRNADCB”
and position were 1 then answer would be “C” and 5
if position were 5 then the answer would be “A” and “9”

and return 0 if none of them appear

a super set of Instr if you will

I have a verion using IF and Instr… but it is overly complex with a lot of conditions… I’ll bet there is a simple FAST Regex based method

2

Use the bar as an “or” operator.

a|b|c|d

You can tell the RegEx object where to start match and will get back a RegExMatch with the position of the first match it finds after that point.

3

It shouldn’t be overly complex. RegEx is the definition of complex if you ask me.

Dim S() As String
S.Append a.Text
S.Append b.Text
S.Append c.Text
S.Append d.Text


Dim SS as String = SourceString.Text
Dim SP as Integer = StartPos.Text.CLong+1
Dim Pos As Integer
Dim ReturnString As String
Dim r() as Integer 

r.Append InStr(SP,SS,S(0))
r.Append InStr(SP,SS,S(1))
r.Append InStr(SP,SS,S(2))
r.Append InStr(SP,SS,S(3))
r.Sort
For i As Integer = 0 To 3
  if r(i) > 0 then
    Pos = r(i)
    exit
  End If
Next
If pos > 0 Then ReturnString = Mid(SS,Pos,1)

Result.text = Pos.ToText + ", " + ReturnString