Yellow is the New Blog

A deeply ingrained habit of mine is using ampersand to concatenate strings in LotusScript (when I'm not bypassing operators entirely, such as using NotesStream or StringBuffer to optimize massive concatenations) - so deeply ingrained that when NTF asked me today why I don't use plus instead, for a moment I couldn't remember my original reason for switching... but after mulling it over briefly I remembered that I hate type coercion with a passion. It bugs me because it tries to be too smart and often fails. Just like extended syntax. For example:

"100" + "200" = "100200"
This may seem obvious: we're concatenating 2 strings, so it takes the value of one and appends the other. But...
100 + "200" = 300
The LotusScript interpreter decides that, since it's starting with a numeric value, you're obviously trying to add another numeric value. Since in this case the string can be converted to a number, it does so and adds the operands instead of concatenating them as strings. So, logically:
"100" + "200" = ...300?
That's right: plus is primarily an addition operator, so if there's any possible way it can remain one, it will. In fact:
100 + "two hundred" = type mismatch - at compile time if it knows the latter is a string, at runtime if it's a variant... reason #372 why variants should be used sparingly and with caution. Speaking of which, I think it was Nathan who once told me, "Variant should have been called Deviant... 'cause it'll accept any object". Yeah, I know, ew. But you gotta admit, that's darned funny.

So how did he convince me plus is better than ampersand despite my pedantic aversion to coercion?

1. (Author's note: this was actually a third realization, which came after the discussion.) In LotusScript string concatenation, some coercion is unavoidable. Since ampersand's only valid use is as a concatenation operator, any scalar entering the operation is treated as a string whether you wanted it to be or not. So unless everything's a string to begin with, it's coercing anyway, it's just safer. But if we're subscribing to a "flexible input, strict output" philosophy, we're already making sure we know what data type we're dealing with and handling it appropriately, so ampersand doesn't really gain us much... it's only when we're being lazy about this that ampersand saves us from returning unexpected results.
   
2. Whenever possible, it's helpful to use conventions that are optional in one language but required in another. In Formula, but - more importantly, over the long haul - also in JavaScript and Java, we don't have a choice: we have to concatenate with plus; might as well do it in LotusScript too so that we're spending more time thinking about how to implement the actual functionality at hand and less time trying to remember what operators to use in the current language... same reason I always surround my conditional expressions in parentheses: I know LotusScript doesn't force me to, but JavaScript and Java do, so why erode a good habit just because LotusScript would allow me to be lazier than that?
3. In XML, an ampersand must be entity-encoded; a plus can be left alone. This was the "you had me at hello" argument. For the foreseeable future, any convention that allows my code to be handled more easily within an XML context is likely to appeal to me, even if it forces me to abandon a long-held alternate approach.

Anything you can think of that I'm overlooking? If not, I'm switching to plus effective immediately. That is, as soon as I get back to writing LotusScript... it's been nothin' but Java for me all week.