From 65ecb85becc5873ad934bf373b25a621dcb70f82 Mon Sep 17 00:00:00 2001
From: Igor Chubin <igor@chub.in>
Date: Sun, 28 May 2017 21:19:10 +0000
Subject: [PATCH] moved scala/ to _scala/

---
 sheets/scala/:main             |  4 --
 sheets/scala/ControlStructures | 54 ------------------------
 sheets/scala/DataStructures    | 29 -------------
 sheets/scala/Functions         | 71 -------------------------------
 sheets/scala/ObjectOrientation | 76 ----------------------------------
 sheets/scala/Packages          | 18 --------
 sheets/scala/PatternMatching   | 29 -------------
 sheets/scala/Variables         | 11 -----
 sheets/scala/hello             |  9 ----
 9 files changed, 301 deletions(-)
 delete mode 100644 sheets/scala/:main
 delete mode 100644 sheets/scala/ControlStructures
 delete mode 100644 sheets/scala/DataStructures
 delete mode 100644 sheets/scala/Functions
 delete mode 100644 sheets/scala/ObjectOrientation
 delete mode 100644 sheets/scala/Packages
 delete mode 100644 sheets/scala/PatternMatching
 delete mode 100644 sheets/scala/Variables
 delete mode 100644 sheets/scala/hello

diff --git a/sheets/scala/:main b/sheets/scala/:main
deleted file mode 100644
index 4c2df01..0000000
--- a/sheets/scala/:main
+++ /dev/null
@@ -1,4 +0,0 @@
-# source:
-#
-# http://docs.scala-lang.org/cheatsheets/
-
diff --git a/sheets/scala/ControlStructures b/sheets/scala/ControlStructures
deleted file mode 100644
index 67f81d5..0000000
--- a/sheets/scala/ControlStructures
+++ /dev/null
@@ -1,54 +0,0 @@
-// conditional
-if (check) happy else sad
-
-// conditional sugar
-if (check) happy // same as
-if (check) happy else () 
-
-// while loop
-while (x < 5) { println(x); x += 1}
-
-// do while loop.
-do { println(x); x += 1} while (x < 5)
-
-// break
-// slides: https://www.slideshare.net/Odersky/fosdem-2009-1013261/21
-import scala.util.control.Breaks._
-breakable {
-  for (x <- xs) {
-    if (Math.random < 0.1) break
-  }
-}
-
-// for comprehension: filter/map
-for (x <- xs if x%2 == 0) yield x*10
-// same as
-xs.filter(_%2 == 0).map(_*10)
-
-// for comprehension: destructuring bind
-for ((x,y) <- xs zip ys) yield x*y
-// same as
-(xs zip ys) map { case (x,y) => x*y }
-
-// for comprehension: cross product
-for (x <- xs; y <- ys) yield x*y
-// same as
-xs flatMap {x => ys map {y => x*y}}
-
-// for comprehension: imperative-ish sprintf-style
-// http://docs.oracle.com/javase/6/docs/api/java/util/Formatter.html#syntax
-for (x <- xs; y <- ys) {
-  println("%d/%d = %.1f".format(x, y, x/y.toFloat))
-}
-
-// for comprehension: iterate including the upper bound
-for (i <- 1 to 5) {
-  println(i)
-}
-
-// for comprehension: iterate omitting the upper bound
-for (i <- 1 until 5) {
-  println(i)
-}
-
-
diff --git a/sheets/scala/DataStructures b/sheets/scala/DataStructures
deleted file mode 100644
index 36957ea..0000000
--- a/sheets/scala/DataStructures
+++ /dev/null
@@ -1,29 +0,0 @@
-// tuple literal. (Tuple3)
-(1,2,3)
-
-// destructuring bind: tuple unpacking via pattern matching.
-var (x,y,z) = (1,2,3)
-
-// hidden error: each assigned to the entire tuple.
-// BAD
-var x,y,z = (1,2,3)
-
-// list (immutable).
-var xs = List(1,2,3)
-
-// paren indexing. (slides)
-// more on it: https://www.slideshare.net/Odersky/fosdem-2009-1013261/27
-xs(2)
-
-// cons.
-1 :: List(2,3)
-
-// range sugar.
-1 to 5 // same as
-1 until 6
-1 to 10 by 2
-
-// sole member of the Unit type (like C/Java void).
-() //(empty parens)
-
-
diff --git a/sheets/scala/Functions b/sheets/scala/Functions
deleted file mode 100644
index 1416026..0000000
--- a/sheets/scala/Functions
+++ /dev/null
@@ -1,71 +0,0 @@
-// define function
-// GOOD 
-def f(x: Int) = { x*x }
-// BAD 
-// hidden error: without = it’s a Unit-returning procedure; causes havoc
-def f(x: Int) { x*x }
-
-// define function
-// GOOD
-def f(x: Any) = println(x)
-// BAD
-// syntax error: need types for every arg.
-def f(x) = println(x)
-
-// type alias
-type R = Double
-
-// call-by-value
-def f(x: R)
-// call-by-name (lazy parameters)
-def f(x: => R)
-
-// anonymous function
-(x:R) => x*x    
-
-// anonymous function: underscore is positionally matched arg.
-(1 to 5).map(_*2) // vs.
-(1 to 5).reduceLeft( _+_ )
-
-//  anonymous function: to use an arg twice, have to name it.
-(1 to 5).map( x => x*x )
-
-// anonymous function: bound infix method. Use 2*_ for sanity’s sake instead.
-// GOOD 
-(1 to 5).map(2*)
-// BAD
-(1 to 5).map(*2)
-
-// anonymous function: block style returns last expression.
-(1 to 5).map { x => val y=x*2; println(y); y }
-
-// anonymous functions: pipeline style. (or parens too).
-(1 to 5) filter {_%2 == 0} map {_*2}
-
-// anonymous functions: to pass in multiple blocks, need outer parens.
-def compose(g:R=>R, h:R=>R) = (x:R) => g(h(x))
-val f = compose({_*2}, {_-1})
-
-// currying, obvious syntax.
-val zscore = (mean:R, sd:R) => (x:R) => (x-mean)/sd
-
-// currying, obvious syntax
-def zscore(mean:R, sd:R) = (x:R) => (x-mean)/sd
-
-// currying, sugar syntax. but then:
-def zscore(mean:R, sd:R)(x:R) = (x-mean)/sd
-
-// need trailing underscore to get the partial, only for the sugar version.
-val normer = zscore(7, 0.4) _
-
-// generic type.
-def mapmake[T](g:T=>T)(seq: List[T]) = seq.map(g)
-
-// infix sugar.
-5.+(3); 5 + 3
-(1 to 5) map (_*2)
-
-// varargs
-def sum(args: Int*) = args.reduceLeft(_+_)
-
-
diff --git a/sheets/scala/ObjectOrientation b/sheets/scala/ObjectOrientation
deleted file mode 100644
index bd9939e..0000000
--- a/sheets/scala/ObjectOrientation
+++ /dev/null
@@ -1,76 +0,0 @@
-// constructor params - private
-class C(x: R) // same as
-class C(private val x: R)
-var c = new C(4)
-
-// constructor params - public
-class C(val x: R)
-var c = new C(4)
-c.x
-
-class C(var x: R) {
-  // constructor is class body
-  assert(x > 0, "positive please")
-  //
-  // declare a public member
-  var y = x
-  //
-  // declare a gettable but not settable member
-  val readonly = 5
-  //
-  // declare a private member
-  private var secret = 1
-  //
-  // alternative constructor
-  def this = this(42)
-}   
-
-// anonymous class
-new{ ... }
-
-// define an abstract class. (non-createable)
-abstract class D { ... }
-
-// define an inherited class.
-class C extends D { ... }
-class D(var x: R)
-
-// inheritance and constructor params. (wishlist: automatically pass-up params by default)
-class C(x: R) extends D(x)
-
-// define a singleton. (module-like)
-object O extends D { ... }
-
-// traits.
-trait T { ... }
-
-// interfaces-with-implementation. no constructor params
-// mixin-able: http://docs.scala-lang.org/tutorials/tour/mixin-class-composition.html
-class C extends T { ... }
-class C extends D with T { ... }
-
-// multiple traits.
-trait T1; trait T2
-class C extends T1 with T2
-class C extends D with T1 with T2
-
-// must declare method overrides.
-class C extends D { override def f = ...}
-
-// create object.
-new java.io.File("f")
-
-new List[Int] // BAD type error: abstract type
-List(1,2,3) // GOOD instead, convention: callable factory shadowing the type
-
-// class literal.
-classOf[String]
-
-// type check (runtime)
-x.isInstanceOf[String]
-
-// type cast (runtime)
-x.asInstanceOf[String]
-
-// ascription (compile time)
-x: String
diff --git a/sheets/scala/Packages b/sheets/scala/Packages
deleted file mode 100644
index 2594621..0000000
--- a/sheets/scala/Packages
+++ /dev/null
@@ -1,18 +0,0 @@
-// wildcard import.
-import scala.collection._
-
-// selective import.
-import scala.collection.Vector
-import scala.collection.{Vector, Sequence}
-
-// renaming import.
-import scala.collection.{Vector => Vec28}
-
-// import all from java.util except Date.
-import java.util.{Date => _, _}
-
-// declare a package.
-package pkg // at start of file
-package pkg { ... }
-
-
diff --git a/sheets/scala/PatternMatching b/sheets/scala/PatternMatching
deleted file mode 100644
index 7153248..0000000
--- a/sheets/scala/PatternMatching
+++ /dev/null
@@ -1,29 +0,0 @@
-// use case in function args for pattern matching.
-(xs zip ys) map { case (x,y) => x*y }   // GOOD 
-(xs zip ys) map( (x,y) => x*y )         // BAD 
-
-// "v42" is interpreted as a name matching any Int value, and "42" is printed.
-// BAD
-val v42 = 42
-Some(3) match {
-  case Some(v42) => println("42")
-  case _ => println("Not 42")
-}
-
-// "`v42`" with backticks is interpreted as the existing val v42, and “Not 42” is printed.
-// GOOD
-val v42 = 42
-Some(3) match {
-  case Some(`v42`) => println("42")
-  case _ => println("Not 42")
-}
-
-// UppercaseVal is treated as an existing val, rather than a new pattern variable, because it starts with an uppercase letter.
-// Thus, the value contained within UppercaseVal is checked against 3, and “Not 42” is printed.
-// GOOD
-val UppercaseVal = 42
-Some(3) match {
-  case Some(UppercaseVal) => println("42")
-  case _ => println("Not 42")
-}
-
diff --git a/sheets/scala/Variables b/sheets/scala/Variables
deleted file mode 100644
index 509257e..0000000
--- a/sheets/scala/Variables
+++ /dev/null
@@ -1,11 +0,0 @@
-// variables
-var x = 5
-
-// constant
-// GOOD
-val x = 5
-// BAD
-x=6
-
-// explicit type
-var x: Double = 5
diff --git a/sheets/scala/hello b/sheets/scala/hello
deleted file mode 100644
index 19373e6..0000000
--- a/sheets/scala/hello
+++ /dev/null
@@ -1,9 +0,0 @@
-// to compile: scalac HelloWorld.scala
-// or          scalac -d classes HelloWorld.scala
-// to execute: scala HelloWorld
-// or          scala -cp classes HelloWorld
-object HelloWorld {
-   def main(args: Array[String]) {
-      println("Hello, world!")
-   }
-}