Are sub-strings strings?

[Petr]

@ahenry3068 

I really like the _mem approach, so I decided to tackle the ridiculous limit on strings. I’ve modified the program to support dynamic strings since the length is known, even if it varies. It seems to work fine. For now, at least...

Code: (Select All)

Dim S As String



S = "ABCDEF "

Print S

Print

SwapChars S$, 2, 3 'ACBDEF

Print S



SwapChars S$, 3, 5 'ACEDBF'



Print S

End



Sub SwapChars (s As String, idx1 As Long, idx2 As Long)

    Dim L As Long: L = Len(s)

    If idx1 < 1 Or idx2 < 1 Then Exit Sub

    If idx1 > L Or idx2 > L Then Exit Sub

    If idx1 = idx2 Then Exit Sub



    Dim m As _MEM

    m = _MemNew(L)



    ' copy string data to own buffer

    _MemPut m, m.OFFSET, s



    Dim b1 As _Unsigned _Byte, b2 As _Unsigned _Byte

    _MemGet m, m.OFFSET + (idx1 - 1), b1

    _MemGet m, m.OFFSET + (idx2 - 1), b2

    _MemPut m, m.OFFSET + (idx1 - 1), b2

    _MemPut m, m.OFFSET + (idx2 - 1), b1



    ' construct new string

    s = Space$(L)

    Dim i As Long, bt As _Unsigned _Byte

    For i = 0 To L - 1

        _MemGet m, m.OFFSET + i, bt

        Mid$(s, i + 1, 1) = Chr$(bt)

    Next



    _MemFree m

End Sub