In an article I wrote about two months ago I showed how you can fix a programming mistake that is quite common among VB6 developers, who tend to believe that the following declaration

     Dim x1, y1, x2, y2 As Integer

declares four integer variables, whereas it actually declares only one integer (y2) and three Variant variables. The solution I proposed required one PreProcess pragma for statements declaring two variables, another PreProcess pragma for statements declaring three variables, and so forth.

Yesterday Marco Giampetruzzi - from the VB Migration Partner Team - surprised me with a better solution that uses just one pragma to account for all Dim, Public, Private, and Static statements, regardless of the number of variables they declare:

    '## PreProcess "(?<=\b(Dim|Public|Private|Static)\b.*)
                    "${var} As ${type}", True

Let me briefly explain how it works. The first regex tells VB Migration Partner to search an identifier and name it as "var" (?<var>\w+). This identifier must preceded on the same line by one of the declaration keywords (?<=\b(Dim|Public|Private|Static)\b.*). To prevent that parameters on a method declaration be mistakenly matched, we also check that the identifier not be preceded by a keyword used in method and property declarations (?<!\b(Sub|Function|Property)\b.*). Next, the regex ensures that the indentifier be immediately followed by a comma and (after some characters) by an As clause (=?,.*\bAs\b\s+(?<type>\w+)). Notice that above pragma doesn't support array declarations.

Very smart indeed... thanks Marco!

You can build similar PreProcess pragmas to account for similar cases. For example, the following pragma adds an As clause to parameters inside method declarations:

    '## PreProcess "(?<=\b(Sub|Function|Property)\b.*)
                    "${var} As ${type}", True

If you aren't familiar with regexes, drop a line to our tech support and we'll cook one for you!