Send Beginners mailing list submissions to
[email protected]
To subscribe or unsubscribe via the World Wide Web, visit
http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners
or, via email, send a message with subject or body 'help' to
[email protected]
You can reach the person managing the list at
[email protected]
When replying, please edit your Subject line so it is more specific
than "Re: Contents of Beginners digest..."
Today's Topics:
1. Re: wierd quickcheck outcome (Roelof Wobben)
----------------------------------------------------------------------
Message: 1
Date: Thu, 10 Sep 2015 14:12:44 +0200
From: Roelof Wobben <[email protected]>
To: The Haskell-Beginners Mailing List - Discussion of primarily
beginner-level topics related to Haskell <[email protected]>
Subject: Re: [Haskell-beginners] wierd quickcheck outcome
Message-ID: <[email protected]>
Content-Type: text/plain; charset=windows-1252; format=flowed
Op 10-9-2015 om 09:54 schreef Frerich Raabe:
> On 2015-09-10 09:23, Roelof Wobben wrote:
>> which I wants to test with this function :
>>
>> prop_fourDifferent :: Integer -> Integer -> Integer -> Integer -> Bool
>> prop_fourDifferent a b c d = fourDifferent a b c d == ( a == b ) && (
>> a == c ) && (a == d)
>
> The problem is that (==) has a higher precedence (4) than (&&) (which
> has precedence 3). So your definition is equivalent to
>
> prop_fourDifferent a b c d = (fourDifferent a b c d == ( a == b ))
> && ( a == c ) && (a == d)
>
> You need some extra parentheses there, try
>
> prop_fourDifferent a b c d = fourDifferent a b c d == (( a == b ) &&
> ( a == c ) && (a == d))
>
Thanks,
Learned that in this sort of situations I have to check the precendence.
Roelof
------------------------------
Subject: Digest Footer
_______________________________________________
Beginners mailing list
[email protected]
http://mail.haskell.org/cgi-bin/mailman/listinfo/beginners
------------------------------
End of Beginners Digest, Vol 87, Issue 4
****************************************
