2015-04-19 22:32:01 +00:00
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Haskell also supports \textbf{list comprehension} which is basically syntactic sugar for what we already know from maths.\\
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Let's define a set that contains the first ten even natural numbers:\\
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\pause
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$S = \{2 \times x\ |\ x \in \mathbb{N},\ x \leq 10\}$
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\vspace{\baselineskip}
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\pause
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\\
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How does this look in haskell?
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\pause
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2015-04-20 18:15:46 +00:00
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\begin{haskellcode*}{bgcolor=mygrey,frame=single,numbers=none,label=GHCi}
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2015-04-20 13:07:59 +00:00
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> [ 2 * x | x <- [1..10]]
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2015-04-20 18:15:46 +00:00
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\end{haskellcode*}
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2015-04-19 22:32:01 +00:00
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\pause
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Now let's say we want all numbers between 50 and 100 that have the remainder 0 when divided by 12:
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\pause
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2015-04-20 18:15:46 +00:00
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\begin{haskellcode*}{bgcolor=mygrey,frame=single,numbers=none,label=GHCi}
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2015-04-19 22:32:01 +00:00
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> [x | x <- [50..100], mod x 12 == 0]
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2015-04-20 18:15:46 +00:00
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\end{haskellcode*}
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2015-04-20 18:55:41 +00:00
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\hinline{x <- [50..100]} is the binding, while \hinline{mod x 12 == 0} is the predicate, separated by a comma. We can have multiple predicates.
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