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1 I've already done Scala development at work, so most of this is just a recap.
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2
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3 A few things I learned:
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4
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5 * Never used traits before - mini classes defined with "trait" keyword and included
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6 like a "mixin" with the "with" keyword to 'inherit' functionality from multiple parents
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7 * Nil is an empty list - probably useful when iterating things and returning a Nil
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8 * foldLeft either uses strange syntax ("start /: list {(a, b) … }") or uses currying
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9 ("list.foldLeft(start)((a,b) …)")
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10 * Strings can be converted to regexes by adding ".r" at the end (I think my work code
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11 managed to do without string matching)
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12 * Pattern matching with a "match… case" on XML can use squiggly brackets to name a variable
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13 (e.g. "case <movie>{movieName}</movie>" matches the tag and puts the contents in movieName)
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14 * Scala has a few minor problems:
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15 * 2.12 (RPM from the website) won't run files as "scala filename.scala" - it needs to be
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16 "scala -nc filename.scala" to disable the compilation daemon
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17 * "scala -e <code>" doesn't seem to want to work without "-nc" either
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18 * If there are dependencies then it is easier to use sbt. Download from
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19 http://www.scala-sbt.org/download.html, create a standard "project/src/scala/package"
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20 structure then create build.sbt within "project/" with the contents:
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21 name := "Project-Name"
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22 version := "1.0"
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23 scalaVersion := "2.12.3"
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24 Run the project by cd-ing into the project directory and running "sbt run"
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25 * Actors have been deprecated and replaced by Akka
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26 * sbt compiles code, so you can't have code outside a class or object
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27 * Akka actors can only act - they can't easily have other methods as well because
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28 creation returns a generic Akka reference to the actor, which doesn't expose the method |
