Var, dim, both. Or Neither ?

Recently there was a blog post on Xojo’s blog from Wayne Golding about how 2019r2 and newer accept VAR as a keyword to declare a variable. And they still accept the older DIM.

There are some issues with VAR IF you ever have to move your code to an older version. I know a lot of developers of commercial software that have to do this so they can continue to support their clients running older versions of various operating systems.

These people have stayed with the older DIM so they can easily move their code simply.

Adding VAR as a keyword has some issues though. While I agree that VAR is an awful parameter or variable name there is code that has used it that now suddenly won’t compile.

One thing I asked for was rather than adding a new keyword, with all the issues that can bring, that we just NOT have to put a DIM or VAR. Then we could write

dim foo as integer
var bar as double
d as date

In a compiler there is usually a “grammar” – a set of rules for what the compiler considers valid code and what it doesn’t. And somewhere in Xojo’s grammar there is a rule that says a variable declaration has to look a specific way. (This is a wild assed guess on my part not actual code since I do not have the code for this)

variableDecl :
      DIM listofVariablesAndTypes
    | VAR  listofVariablesAndTypes

and listofVariablesAndTypes is additional rules for how to declare one or more variables with default values in a single line. Making this grammar rule

variableDecl :
      DIM listofVariablesAndTypes
    | VAR  listofVariablesAndTypes
    | listofVariablesAndTypes

(or something like this) would make it so DIM and VAR are not required.

I’d find it handy.

How about you ?