Hello, café:
I am trying to use more than one array with runSTUArray but I don't seem
to be able to understand how it works. My first try is this:
test1 n = runSTUArray $ do
a <- newArray (1, n) (2::Int)
b <- newArray (1, n) (3::Int)
forM_ [1..n] $ \i -> do
v <- readArray a i
writeArray b i (v+1)
return b
but it does not work. However, when I write
test2 n = runSTUArray $ do
let createArray v n = newArray (1, n) (v::Int)
a <- createArray 2 n
b <- createArray 0 n
forM_ [1..n] $ \i -> do
v <- readArray a i
writeArray b i (v+1)
return b
everything is fine although I expected the two versions to be
equivalent. To further complicate matters, the following
createArray v n = newArray (1, n) (v::Int)
test3 n = runSTUArray $ do
a <- createArray 2 n
b <- createArray 3 n
forM_ [1..n] $ \i -> do
v <- readArray a i
writeArray b i (v+1)
return b
does not work either. Where can I find an explanation for this
behaviour? Furthermore, what I am after is to use two arrays with
different types (Int and Bool), is it possible?
Thanks in advance,
Juan Miguel
--
Juan Miguel Vilar Torres
Profesor titular de universidad
Vicedirector de la ESTCE para ITIG e ITIS
Departamento de Lenguajes y Sistemas Informáticos
Escuela Superior de Tecnología y Ciencias Experimentales
Universitat Jaume I
Av. de Vicent Sos Baynat s/n
12071 Castelló de la Plana (Spain)
Tel: +34 964 72 8365
Fax: +34 964 72 8435
jvi...@lsi.uji.es
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