1) spreadsheets are a purely functional programming language. When you point this out to management users of it (after explaining what it is), they wouldn't want to live without it.
So in reality the most widely used programming language in the world, is a purely functional one.
2) they are NOT turing complete (assuming you stay away from VBScript)
Of course, they're worse than BASIC when it comes to naming things, which is what everyone here is complaining about. But these are major advantages, to be fair. The only thing that comes even vaguely close to how spreadsheets work are the IPython notebooks.
It looks like it uses one row per step. Excel supports finite rows, and hence this does not prove that Excel is Turing complete. A program like while(true); will eventually run out of rows and terminate.
Re. naming things, In the original BASIC, variable names were also quite limited. A-Z, A[0-9]-Z[0-9], which is actually an even more limited space than most spreadsheets which allow for something like [A-Z]{1,4},[0-9]{1,4} at least.
You could also argue that spreadsheets are kind of homoiconic, since code and data occupy the same structure. But that's a bit of a stretch.
1) spreadsheets are a purely functional programming language. When you point this out to management users of it (after explaining what it is), they wouldn't want to live without it.
So in reality the most widely used programming language in the world, is a purely functional one.
2) they are NOT turing complete (assuming you stay away from VBScript)
Of course, they're worse than BASIC when it comes to naming things, which is what everyone here is complaining about. But these are major advantages, to be fair. The only thing that comes even vaguely close to how spreadsheets work are the IPython notebooks.