2011-05-30

ANNOUNCE: dimensional-0.10

I just released version 0.10 of the dimensional library, adding an Enum instance for quantities. Thus now it is possible to, e.g.:

> import Numeric.Units.Dimensional.Prelude
> import qualified Prelude
> xs = [1 *~ meter..]  -- [1 m, 2 m, 3 m...]

However, I just realised that the behaviour may occasionally be surprising unless one keeps in mind that the default increment will be a product of SI base units and the value 1. For example:

> ys = [1 *~ kilo meter..]  -- [1000 m, 1001 m, 1002 m...]

In order to avoid shooting oneself in the foot I recommended sticking with the enumFromThen or enumFromThenTo forms:

> zs = [1 *~ kilo meter, 2 *~ kilo meter..]  -- [1000 m, 2000 m, 3000 m...]

Another option is to use *~~ (see my previous post):

> zs' = [1..] *~~ kilo meter  -- [1000 m, 2000 m, 3000 m...]

In other news I’ve added a “search this blog” widget to the right to help myself find my pandoc article that I need to refer to every time I post. Feel free to use it!

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