| author | Christian Urban <urbanc@in.tum.de> |
| Wed, 16 Nov 2016 15:05:40 +0000 | |
| changeset 51 | 0e60e6c24b99 |
| parent 39 | c6fe374a5fca |
| child 53 | 9f8751912560 |
| permissions | -rw-r--r-- |
| 51 | 1 |
// Scala Lecture 2 |
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//================= |
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// Option type |
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//============= |
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val lst = List(None, Some(1), Some(2), None, Some(3)) |
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lst.flatten |
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Some(1).get |
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val ps = List((3, 0), (3, 2), (4, 2), (2, 0), (1, 0), (1, 1)) |
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for ((x, y) <- ps) yield {
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if (y == 0) None else Some(x / y) |
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} |
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// sudoku |
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0ce25f816414
updated
Christian Urban <christian dot urban at kcl dot ac dot uk>
parents:
8
diff
changeset
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// some none |
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// pattern matching |
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//type abbreviations |
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type Pos = (int, Int) |
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//sorting, higher-order functions |
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//lexicographic ordering |
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// Implicits |
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//=========== |
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// |
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// for example adding your own methods to Strings: |
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// imagine you want to increment strings, like |
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// |
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// "HAL".increment |
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// |
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// you can avoid ugly fudges, like a MyString, by |
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// using implicit conversions |
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implicit class MyString(s: String) {
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def increment = for (c <- s) yield (c + 1).toChar |
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} |
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"HAL".increment |