[Haskell-cafe] Examples of using STUArray + help with converting
u.stenzel at web.de
Fri Oct 14 10:45:14 EDT 2005
joel reymont wrote:
> I don't understand the syntax needed to create a new double or float
> array with newArray from Data.Array.MArray. I also don't yet
> understand how to cast that double array to read ints from it.
> doubleToInts d = runST (
> do arr <- newDoubleArray (1,2)
> writeDoubleArray arr 1 d
> i1 <- readIntArray arr 1
> i2 <- readIntArray arr 2
> return (i1,i2))
Just use newArray, writeArray and readArray. Something (writeArray is
probably the easiest) will need an explicit type signature to resolve
the overloading. Also from the GHC docs:
castSTUArray :: STUArray s ix a -> ST s (STUArray s ix b)
Casts an STUArray with one element type into one with a different
element type. All the elements of the resulting array are undefined
(unless you know what you're doing...).
Note the part in parentheses. This is Haskell, not C after all. A
clean solution may not be that far away.
I underthand that people theem to like it better now.
That it ith written in thee pluth pluth inthtead of lithp.
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