//############################################################################
// for-comprehensions (old and new syntax)
//############################################################################
//############################################################################
object Test extends Application {
val xs = List(1, 2, 3)
val ys = List('a, 'b, 'c)
def it = 0 until 10
val ar = "abc".toCharArray
val xml =
Scala
{xs}
;
/////////////////// old syntax ///////////////////
def testOld {
println("\ntestOld")
// lists
for (val x <- xs) print(x + " "); println
for (val x <- xs;
x % 2 == 0) print(x + " "); println
for {val x <- xs
x % 2 == 0} print(x + " "); println
var n = 0
for (val _ <- xs) n += 1; println(n)
for (val (x, y) <- xs zip ys) print(x + " "); println
for (val p @ (x, y) <- xs zip ys) print(p._1 + " "); println
// iterators
for (val x <- it) print(x + " "); println
for (val x <- it;
x % 2 == 0) print(x + " "); println
for {val x <- it
x % 2 == 0} print(x + " "); println
// arrays
for (val x <- ar) print(x + " "); println
for (val x <- ar;
x.toInt > 97) print(x + " "); println
for {val x <- ar
x.toInt > 97} print(x + " "); println
// sequences
for (val x <- xml.child) println(x)
for (val x <- xml.child;
x.label == "head") println(x)
}
/////////////////// new syntax ///////////////////
def testNew {
println("\ntestNew")
// lists
var n = 0
for (_ <- xs) n += 1; println(n)
for ((x, y) <- xs zip ys) print(x + " "); println
for (p @ (x, y) <- xs zip ys) print(p._1 + " "); println
// iterators
for (x <- it) print(x + " "); println
for (x <- it if x % 2 == 0) print(x + " "); println
for (x <- it; if x % 2 == 0) print(x + " "); println
for (x <- it;
if x % 2 == 0) print(x + " "); println
for (x <- it
if x % 2 == 0) print(x + " "); println
for {x <- it
if x % 2 == 0} print(x + " "); println
for (x <- it;
val y = 2
if x % y == 0) print(x + " "); println
for {x <- it
val y = 2
if x % y == 0} print(x + " "); println
// arrays
for (x <- ar) print(x + " "); println
// sequences
for (x <- xml.child) println(x)
for (x <- xml.child if x.label == "head") println(x)
}
////////////////////////////////////////////////////
testOld
testNew
}