error: Not in scope: data constructor `BinTree'

Kak Dod

13 Apr 2012 13 Apr '12

12:23 p.m.

if i compile the following code I get "bintree.hs:3:13: Not in scope: data constructor `BinTree'" data BinTree a = Node BinTree a BinTree a | EmptyBinTree deriving Show b1 = (Node (BinTree 3) EmptyBinTree) please help -kak

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Kyle Murphy

13 Apr 13 Apr

12:38 p.m.

New subject: error: Not in scope: data constructor `BinTree'

Your constructor is called Node, not BinTree. data BinTree a = Node a (BinTree a) (BinTree a) | EmptyNode b1 = Node 3 EmptyNode EmptyNode -R. Kyle Murphy Sent from my phone. On Apr 13, 2012 12:24 PM, "Kak Dod" wrote:

...

if i compile the following code I get "bintree.hs:3:13: Not in scope: data constructor `BinTree'"

data BinTree a = Node BinTree a BinTree a | EmptyBinTree deriving Show

b1 = (Node (BinTree 3) EmptyBinTree)

please help

-kak

_______________________________________________ Beginners mailing list Beginners@haskell.org http://www.haskell.org/mailman/listinfo/beginners

Kak Dod

12:46 p.m.

New subject: error: Not in scope: data constructor `BinTree'

Thank you but if I change the code like this: data BinTree a = Node BinTree a BinTree a | EmptyBinTree deriving Show b1 = Node 3 EmptyBinTreeEmptyBinTree Then I am get this error: bintree.hs:1:23: `BinTree' is not applied to enough type arguments Expected kind `?', but `BinTree' has kind `k0 -> *' In the type `BinTree' In the definition of data constructor `Node' In the data type declaration for `BinTree' Failed, modules loaded: none. ________________________________ From: Kyle Murphy To: Kak Dod Cc: "beginners@haskell.org" Sent: Friday, 13 April 2012 4:38 PM Subject: Re: [Haskell-beginners] error: Not in scope: data constructor `BinTree' Your constructor is called Node, not BinTree. data BinTree a = Node a (BinTree a) (BinTree a) | EmptyNode b1 = Node 3 EmptyNode EmptyNode -R. Kyle Murphy Sent from my phone. On Apr 13, 2012 12:24 PM, "Kak Dod" wrote: if i compile the following code I get "bintree.hs:3:13: Not in scope: data constructor `BinTree'"

...

data BinTree a = Node BinTree a BinTree a | EmptyBinTree deriving Show

b1 = (Node (BinTree 3) EmptyBinTree)

please help

-kak

_______________________________________________ Beginners mailing list Beginners@haskell.org http://www.haskell.org/mailman/listinfo/beginners

Tom Murphy

12:53 p.m.

New subject: error: Not in scope: data constructor `BinTree'

"(BinTree a)" needs to be in parentheses to pattern-match properly. data BinTree a = Node (BinTree a) (BinTree) a | EmptyBinTree deriving Show On 4/13/12, Kak Dod wrote:

...

Thank you but

if I change the code like this:

data BinTree a = Node BinTree a BinTree a | EmptyBinTree deriving Show

b1 = Node 3 EmptyBinTreeEmptyBinTree

Then I am get this error:

bintree.hs:1:23: `BinTree' is not applied to enough type arguments Expected kind `?', but `BinTree' has kind `k0 -> *' In the type `BinTree' In the definition of data constructor `Node' In the data type declaration for `BinTree' Failed, modules loaded: none.

________________________________ From: Kyle Murphy To: Kak Dod Cc: "beginners@haskell.org" Sent: Friday, 13 April 2012 4:38 PM Subject: Re: [Haskell-beginners] error: Not in scope: data constructor `BinTree'

Your constructor is called Node, not BinTree. data BinTree a = Node a (BinTree a) (BinTree a) | EmptyNode b1 = Node 3 EmptyNode EmptyNode -R. Kyle Murphy Sent from my phone. On Apr 13, 2012 12:24 PM, "Kak Dod" wrote:

if i compile the following code I get "bintree.hs:3:13: Not in scope: data constructor `BinTree'"

...
data BinTree a = Node BinTree a BinTree a | EmptyBinTree deriving Show

b1 = (Node (BinTree 3) EmptyBinTree)

please help

-kak

_______________________________________________ Beginners mailing list Beginners@haskell.org http://www.haskell.org/mailman/listinfo/beginners

Kak Dod

1:02 p.m.

New subject: error: Not in scope: data constructor `BinTree'

Thanks Tom. this is what i wanted I do not want "Node a" there, I wants only Node and Tom's solution works. Thanks to all . ________________________________ From: Tom Murphy To: Kak Dod Cc: Kyle Murphy ; "beginners@haskell.org" Sent: Friday, 13 April 2012 4:53 PM Subject: Re: [Haskell-beginners] error: Not in scope: data constructor `BinTree' "(BinTree a)" needs to be in parentheses to pattern-match properly. data BinTree a = Node (BinTree a) (BinTree) a | EmptyBinTree deriving Show On 4/13/12, Kak Dod wrote:

...

Thank you but

if I change the code like this:

data BinTree a = Node BinTree a BinTree a | EmptyBinTree deriving Show

b1 = Node 3 EmptyBinTreeEmptyBinTree

Then I am get this error:

bintree.hs:1:23: `BinTree' is not applied to enough type arguments Expected kind `?', but `BinTree' has kind `k0 -> *' In the type `BinTree' In the definition of data constructor `Node' In the data type declaration for `BinTree' Failed, modules loaded: none.

________________________________ From: Kyle Murphy To: Kak Dod Cc: "beginners@haskell.org" Sent: Friday, 13 April 2012 4:38 PM Subject: Re: [Haskell-beginners] error: Not in scope: data constructor `BinTree'

Your constructor is called Node, not BinTree. data BinTree a = Node a (BinTree a) (BinTree a) | EmptyNode b1 = Node 3 EmptyNode EmptyNode -R. Kyle Murphy Sent from my phone. On Apr 13, 2012 12:24 PM, "Kak Dod" wrote:

if i compile the following code I get "bintree.hs:3:13: Not in scope: data constructor `BinTree'"

...
data BinTree a = Node BinTree a BinTree a | EmptyBinTree deriving Show

b1 = (Node (BinTree 3) EmptyBinTree)

please help

-kak

_______________________________________________ Beginners mailing list Beginners@haskell.org http://www.haskell.org/mailman/listinfo/beginners

Kyle Murphy

2:32 p.m.

New subject: error: Not in scope: data constructor `BinTree'

If you don't include "Node a" then there isn't any point in having the a parameter on BinTree as it's never used unless you add another constructor that uses it. I based the modification on the usage in your example where you're trying to store a value of 3. Without that parameter the code becomes: b1 = Node EmptyBinTree EmptyBinTree I haven't tried it, but that will also likely complain it can't deduce "a" from the usage. -R. Kyle Murphy Sent from my phone. On Apr 13, 2012 1:03 PM, "Kak Dod" wrote:

...

Thanks Tom. this is what i wanted I do not want "Node a" there, I wants only Node and Tom's solution works. Thanks to all .

------------------------------ *From:* Tom Murphy *To:* Kak Dod *Cc:* Kyle Murphy ; "beginners@haskell.org" < beginners@haskell.org> *Sent:* Friday, 13 April 2012 4:53 PM *Subject:* Re: [Haskell-beginners] error: Not in scope: data constructor `BinTree'

"(BinTree a)" needs to be in parentheses to pattern-match properly.

data BinTree a = Node (BinTree a) (BinTree) a | EmptyBinTree deriving Show

On 4/13/12, Kak Dod wrote:

...
Thank you but

if I change the code like this:

data BinTree a = Node BinTree a BinTree a | EmptyBinTree deriving Show

b1 = Node 3 EmptyBinTreeEmptyBinTree

Then I am get this error:

bintree.hs:1:23: `BinTree' is not applied to enough type arguments Expected kind `?', but `BinTree' has kind `k0 -> *' In the type `BinTree' In the definition of data constructor `Node' In the data type declaration for `BinTree' Failed, modules loaded: none.

________________________________ From: Kyle Murphy To: Kak Dod Cc: "beginners@haskell.org" Sent: Friday, 13 April 2012 4:38 PM Subject: Re: [Haskell-beginners] error: Not in scope: data constructor `BinTree'

Your constructor is called Node, not BinTree. data BinTree a = Node a (BinTree a) (BinTree a) | EmptyNode b1 = Node 3 EmptyNode EmptyNode -R. Kyle Murphy Sent from my phone. On Apr 13, 2012 12:24 PM, "Kak Dod" wrote:

if i compile the following code I get "bintree.hs:3:13: Not in scope: data constructor `BinTree'"

...
data BinTree a = Node BinTree a BinTree a | EmptyBinTree deriving Show

b1 = (Node (BinTree 3) EmptyBinTree)

please help

-kak

_______________________________________________ Beginners mailing list Beginners@haskell.org http://www.haskell.org/mailman/listinfo/beginners

Kak Dod

3:28 p.m.

New subject: error: Not in scope: data constructor `BinTree'

I wants to create things that way only, yes, later I may add another constructor like "Leaf a" sorry for the confusion in my question . now i comes to know that all I wants to know was syntax of how to write "Node BinTree a" instead of "Node a BinTree a" and there was many horrorful error messages like: Expected kind `?', but `BinTree' has kind `k0 -> *' that why i have panic that time i was not seen that error earlier thank you for answer ________________________________ From: Kyle Murphy To: Kak Dod Cc: Tom Murphy ; "beginners@haskell.org" Sent: Friday, 13 April 2012 6:32 PM Subject: Re: [Haskell-beginners] error: Not in scope: data constructor `BinTree' If you don't include "Node a" then there isn't any point in having the a parameter on BinTree as it's never used unless you add another constructor that uses it. I based the modification on the usage in your example where you're trying to store a value of 3. Without that parameter the code becomes: b1 = Node EmptyBinTree EmptyBinTree I haven't tried it, but that will also likely complain it can't deduce "a" from the usage. -R. Kyle Murphy Sent from my phone. On Apr 13, 2012 1:03 PM, "Kak Dod" wrote: Thanks Tom. this is what i wanted

...

I do not want "Node a" there, I wants only Node and Tom's solution works. Thanks to all .

________________________________ From: Tom Murphy To: Kak Dod Cc: Kyle Murphy ; "beginners@haskell.org" Sent: Friday, 13 April 2012 4:53 PM Subject: Re: [Haskell-beginners] error: Not in scope: data constructor `BinTree'

"(BinTree a)" needs to be in parentheses to pattern-match properly.

data BinTree a = Node (BinTree a) (BinTree) a | EmptyBinTree deriving Show

On 4/13/12, Kak Dod wrote:

...
Thank you but

if I change the code like this:

data BinTree a = Node BinTree a BinTree a | EmptyBinTree deriving Show

b1 = Node 3 EmptyBinTreeEmptyBinTree

Then I am get this error:

bintree.hs:1:23:     `BinTree' is not applied to enough type arguments     Expected kind `?', but `BinTree' has kind `k0 -> *'

    In the type `BinTree'

...
    In the definition of data constructor `Node'     In the data type declaration for `BinTree' Failed, modules loaded: none.

________________________________ From: Kyle Murphy To: Kak Dod Cc: "beginners@haskell.org" Sent: Friday, 13 April 2012 4:38 PM Subject: Re: [Haskell-beginners] error: Not in scope: data constructor `BinTree'

Your constructor is called Node, not BinTree. data BinTree a = Node a (BinTree a) (BinTree a) | EmptyNode b1 = Node 3 EmptyNode EmptyNode -R. Kyle Murphy Sent from my phone. On Apr 13, 2012 12:24 PM, "Kak Dod" wrote:

if i compile the following code I get "bintree.hs:3:13: Not in scope: data constructor `BinTree'"

...
data BinTree a = Node BinTree a BinTree a | EmptyBinTree deriving Show

b1 = (Node (BinTree 3) EmptyBinTree)

please help

-kak

_______________________________________________ Beginners mailing list Beginners@haskell.org http://www.haskell.org/mailman/listinfo/beginners

Antoine Latter

12:54 p.m.

New subject: error: Not in scope: data constructor `BinTree'

On Fri, Apr 13, 2012 at 11:46 AM, Kak Dod wrote:

...

Thank you but if I change the code like this:

data BinTree a = Node BinTree a BinTree a | EmptyBinTree deriving Show

If you look closely, Kyle made other changes to your code as well :-) Antoine

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Antoine Latter
Kak Dod
Kyle Murphy
Tom Murphy