I still think I'm missing your point, but let me take a stab at it.
Conal Elliott wrote:
I'm suggesting you might better understand the why of Haskell if you think denotationally (here about the meaning of the [String] type), rather than operationally.
The meaning of a type seems to be about what happens operationally. ":: [String]" is an operational guarantee, so if we let "getArgs :: [String]" that is a promise that there is some list of Strings at runtime.
> I'm
guessing that none of those 2^32+1 values is what you'd mean by "length getArgs".
Well, I suppose I mean something like an existential type: there is some Int that is length getArgs.
Even if this is denotationally different from a value like zero :: Int, I think it is also different from getLine :: IO String. It seems to mean something between these. I suppose my intuition is that it is closer to :: Int
Jim
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