The last statement in a 'do' construct must be an expression: a <- readArray arr (1, 1)

[KC]

I'm getting the above error message and I cannot figure out why?

buildPair =

    do

arr <- newArray ((1,1),(1,10)) 37 :: ST s (STArray s (Int,Int) Int)

a <- readArray arr (1,1)

        writeArray arr (1,1) 64

        b <- readArray arr (1,1)

        return (a,b)

main = print $ runST buildPair

--
--
Regards,
KC

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[Ryan Yates]

Perhaps you are mixing tabs and spaces?

On Mon, Apr 23, 2012 at 4:52 PM, KC <[hidden email]> wrote:

I'm getting the above error message and I cannot figure out why?

buildPair =

    do

arr <- newArray ((1,1),(1,10)) 37 :: ST s (STArray s (Int,Int) Int)

a <- readArray arr (1,1)

        writeArray arr (1,1) 64

        b <- readArray arr (1,1)

        return (a,b)

main = print $ runST buildPair

--
--
Regards,
KC

_______________________________________________
Haskell-Cafe mailing list
[hidden email]
http://www.haskell.org/mailman/listinfo/haskell-cafe

_______________________________________________
Haskell-Cafe mailing list
[hidden email]
http://www.haskell.org/mailman/listinfo/haskell-cafe

[KC]

Thank you, that was it.

I was mixing up and tabs and spaces.

I expected new versions of NotePad++ to keep my old settings.

On Mon, Apr 23, 2012 at 1:54 PM, Ryan Yates <[hidden email]> wrote:

Perhaps you are mixing tabs and spaces?

On Mon, Apr 23, 2012 at 4:52 PM, KC <[hidden email]> wrote:

I'm getting the above error message and I cannot figure out why?

buildPair =

    do

arr <- newArray ((1,1),(1,10)) 37 :: ST s (STArray s (Int,Int) Int)

a <- readArray arr (1,1)

        writeArray arr (1,1) 64

        b <- readArray arr (1,1)

        return (a,b)

main = print $ runST buildPair

--
--
Regards,
KC

_______________________________________________
Haskell-Cafe mailing list
[hidden email]
http://www.haskell.org/mailman/listinfo/haskell-cafe

--
--
Regards,
KC

_______________________________________________
Haskell-Cafe mailing list
[hidden email]
http://www.haskell.org/mailman/listinfo/haskell-cafe