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more syntax/types slides

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1 parent 5324e85 commit 0eb93d31f5123ead0346c2d36dbdf440d3bdcd0f @astro astro committed Aug 28, 2012
Showing with 84 additions and 7 deletions.
  1. +9 −0 astro.hs
  2. +75 −7 index.html
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9 astro.hs
@@ -24,3 +24,12 @@ fac''' n =
facs = 1 : go 2
where go :: Integer -> [Integer]
go n = n : map (* n) (go (n + 1))
+
+fib :: Integer -> Integer
+fib 0 = 0
+fib 1 = 1
+fib n =
+ let r = fib $ n - 1
+ r' = fib $ n - 2
+ in r + r'
+
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82 index.html
@@ -106,7 +106,7 @@
<div class="slide">
<h2>Listen</h2>
- <pre class="sh_haskell">$ ghci
+ <pre class="sh_haskell">$ ghci <p class="note">REPL</p>
Prelude> 2 : []
[2]
Prelude> 23 : []
@@ -118,30 +118,98 @@
Prelude> :t (:)
(:) :: a -> [a] -> [a]
</pre>
+ <pre class="sh_haskell">Prelude> :t map
+map :: (a -> b) -> [a] -> [b]
+Prelude> :t filter
+filter :: (a -> Bool) -> [a] -> [a]
+Prelude> :t foldl
+foldl :: (a -> b -> a) -> a -> [b] -> a
+ </pre>
<p class="note"></p>
</div>
<div class="slide">
- <h2>Listen</h2>
+ <h2>let</h2>
+ <pre class="sh_haskell">fib :: Integer -> Integer
+fib 0 = 0
+fib 1 = 1
+fib n =
+ let r = fib $ n - 1
+ r' = fib $ n - 2
+ in r + r'
+ </pre>
+
+ <h2>where</h2>
<pre class="sh_haskell">facs = 1 : go 2
- where go :: Integer -> [Integer]
+ where go :: Integer -> [Integer] <span class="note">“Unterfunktion”</span>
go n = n : map (* n) (go $ n + 1)
-Prelude> facs !! 500
+Prelude> :t facs <span class="note">Inferred type</span>
+facs :: [Integer]
+Prelude> facs !! 500 <span class="note">Unendlich, lazy</span>
611288549821546144419320631496946510053040745744399613938399207781308531950094880800353720198603844213369821855051249995665852739761166777440873387784823972024431693541604632490253390402221485016448489094881275898497140756808655499992463957536774753658273522343143352081610678258299859781290947510064133164625417126214683287364306533202043771696934819148200603488701298578593288295101675375228475039194518540926501811512211084741146359555616051391364512171815202852428391973770531819587555590747725222707870915089204322125602187745638954304887403405330317436980872692673627514602895425139803517823839455807896878364709108235036658336397561844224198282288969461157203049314666899393600517284430144216183492154249948251192663554129489210224225335784718743202172831724716080857069568307715110065035130707514179942202121569852186583424945734289322385681601382444331381680307765142985006245859526451817213228740320341074735777885270328149239431528071389670544598095262337701383222299067569757970109034425702794542448640000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
</pre>
+
<p class="note">($)</p>
</div>
<!--
-let/where
module
-lambdas
-->
<div class="slide">
+ <h2>Lambdas</h2>
+ <p class="note">Num: Interface für (+), (*)</p>
+ <pre class="sh_haskell">Prelude> :t (\n -> n + 1)
+(\n -> n + 1) :: Num a => a -> a
+Prelude> (\n -> n + 1) 22
+23
+</pre>
+ <pre class="sh_haskell">Prelude> :t (\a b c -> a * b * c)
+(\a b c -> a * b * c) :: Num a => a -> a -> a -> a
+ </pre>
+ <pre class="sh_haskell">Prelude> :t (\a -> \b -> \c -> a * b * c)
+(\a -> \b -> \c -> a * b * c) :: Num a => a -> a -> a -> a
+ </pre>
+ <p class="note">Umkehrschluß: Currying</p>
+</div>
+<div class="slide">
<h2>Currying</h2>
+ <pre class="sh_haskell">:t map (\a -> a + 1)
+map (\a -> a + 1) :: Num b => [b] -> [b]
+ </pre>
+
+ <h2>Sections</h2>
+ <pre class="sh_haskell">Prelude> :t (+ 1)
+(+ 1) :: Num a => a -> a
+Prelude> map (+ 1) [1..10]
+[2,3,4,5,6,7,8,9,10,11]
+ </pre>
+</div>
+
+<!-- Types -->
+<div class="slide">
+ <h2>data</h2>
+ <p class="note">Statt NULL-Pointer</p>
+ <pre class="sh_haskell">data Maybe a = Nothing
+ | Just a
+</pre>
+ <pre class="sh_haskell">Prelude> :t Nothing <span class="note">Constructors</span>
+Nothing :: Maybe a <span class="note">Passt auf alle a</span>
+Prelude> :t Just
+Just :: a -> Maybe a
+</pre>
+ <pre class="sh_haskell">data [] a = []
+ | a : [a]</pre>
+ <h2>newtype</h2>
+ <pre class="sh_haskell">newtype Name = Name String <span class="note">Typename = Ctor</span></pre>
+ <ul>
+ <li>Darf nur 1 Feld haben</li>
+ <li>Billig zur Laufzeit</li>
+ <li>Typsicher zur Compile-Zeit</li>
+ </ul>
</div>
-<!-- sections -->
+
+<!-- Classes, instances -->
<!--
* Monads, Functors, Applicatives (maloi) (30 min)

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