Re: [Haskell-beginners] map increases length of list

17 Jun 2009

      Sigh.

Well, what I was trying to do was get all angles in the range [0, 360)  
that have 60 degrees between them, since I'm going to be working with  
hexagons.  I figured I'd use a range instead of hard-coded angles in  
case I wanted to use other shapes.

Thanks,

Aaron

On 17-Jun-09, at 6:58 PM, Henk-Jan van Tuyl wrote:
...
On Wed, 17 Jun 2009 23:35:23 +0200, Aaron MacDonald 
...
wrote:
...
This is how I'm calling map overall:
-----
...
map degreesToRadians [0,60..359]
[0.0,1.0471975511965976,2.0943951023931953,3.141592653589793,4.1887902047863905,5.235987755982989,6.283185307179586 
]

As you can hopefully see, there are seven elements instead of six.  
Getting the length confirms this:
-----
...
length [0,60..359]
6
length $ map degreesToRadians [0,60..359]
7

Enumeration works differently for Double:
 Prelude> [0, 60..359 :: Double]
 [0.0,60.0,120.0,180.0,240.0,300.0,360.0]
 Prelude> length [0, 60..359 :: Double]
 7
-- 
Met vriendelijke groet,
Henk-Jan van Tuyl
--
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