[Haskell-cafe] Small optimisation question

[Andrew Coppin]

Stefan O'Rear wrote:
> On Sat, Nov 17, 2007 at 04:01:34PM +0000, Andrew Coppin wrote:
>   
>> Suppose I write something like this:
>>
>>  foo :: [Int]
>>  foo = concat (replicate 4 [4,7,2,9])
>>
>> The value of "foo" is completely determined at compile-time. So, will the 
>> compiler generate calls to concat and replicate, or will it just insert a 
>> large list constant here?
>>     
> The compiler will generate calls to concat and replicate.
>   

OK. I presume this is due to the fact that the result of executing an 
expression at compile-time could be arbitrarily large?

Are there any buttons that can be twiddled to control this behaviour?


For that matter, when I say "[4,7,2,9]", what does that compile into? 
Some data structures in memory? Or code to actually build said structures?