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/* NSC -- new Scala compiler
* Copyright 2005-2011 LAMP/EPFL
* @author Paul Phillips
*/
package scala.reflect.internal.util
import scala.collection.{ mutable, immutable }
import scala.annotation.tailrec
import mutable.ListBuffer
/** Profiler driven changes.
* TODO - inlining doesn't work from here because of the bug that
* methods in traits aren't inlined.
*/
trait Collections {
/** True if all three arguments have the same number of elements and
* the function is true for all the triples.
*/
@tailrec final def corresponds3[A, B, C](xs1: List[A], xs2: List[B], xs3: List[C])
(f: (A, B, C) => Boolean): Boolean = (
if (xs1.isEmpty) xs2.isEmpty && xs3.isEmpty
else !xs2.isEmpty && !xs3.isEmpty && f(xs1.head, xs2.head, xs3.head) && corresponds3(xs1.tail, xs2.tail, xs3.tail)(f)
)
/** All these mm methods are "deep map" style methods for
* mapping etc. on a list of lists while avoiding unnecessary
* intermediate structures like those created via flatten.
*/
final def mexists[A](xss: List[List[A]])(p: A => Boolean) =
xss exists (_ exists p)
final def mforall[A](xss: List[List[A]])(p: A => Boolean) =
xss forall (_ forall p)
final def mmap[A, B](xss: List[List[A]])(f: A => B) =
xss map (_ map f)
final def mforeach[A](xss: List[List[A]])(f: A => Unit) =
xss foreach (_ foreach f)
final def mfind[A](xss: List[List[A]])(p: A => Boolean): Option[A] = {
var res: Option[A] = null
mforeach(xss)(x => if ((res eq null) && p(x)) res = Some(x))
if (res eq null) None else res
}
final def mfilter[A](xss: List[List[A]])(p: A => Boolean) =
for (xs <- xss; x <- xs; if p(x)) yield x
final def map2[A, B, C](xs1: List[A], xs2: List[B])(f: (A, B) => C): List[C] = {
val lb = new ListBuffer[C]
var ys1 = xs1
var ys2 = xs2
while (!ys1.isEmpty && !ys2.isEmpty) {
lb += f(ys1.head, ys2.head)
ys1 = ys1.tail
ys2 = ys2.tail
}
lb.toList
}
final def map3[A, B, C, D](xs1: List[A], xs2: List[B], xs3: List[C])(f: (A, B, C) => D): List[D] = {
if (xs1.isEmpty || xs2.isEmpty || xs3.isEmpty) Nil
else f(xs1.head, xs2.head, xs3.head) :: map3(xs1.tail, xs2.tail, xs3.tail)(f)
}
final def flatMap2[A, B, C](xs1: List[A], xs2: List[B])(f: (A, B) => List[C]): List[C] = {
val lb = new ListBuffer[C]
var ys1 = xs1
var ys2 = xs2
while (!ys1.isEmpty && !ys2.isEmpty) {
lb ++= f(ys1.head, ys2.head)
ys1 = ys1.tail
ys2 = ys2.tail
}
lb.toList
}
final def flatCollect[A, B](elems: List[A])(pf: PartialFunction[A, Traversable[B]]): List[B] = {
val lb = new ListBuffer[B]
for (x <- elems ; if pf isDefinedAt x)
lb ++= pf(x)
lb.toList
}
final def distinctBy[A, B](xs: List[A])(f: A => B): List[A] = {
val buf = new ListBuffer[A]
val seen = mutable.Set[B]()
xs foreach { x =>
val y = f(x)
if (!seen(y)) {
buf += x
seen += y
}
}
buf.toList
}
@tailrec final def flattensToEmpty(xss: Seq[Seq[_]]): Boolean = {
xss.isEmpty || xss.head.isEmpty && flattensToEmpty(xss.tail)
}
final def foreachWithIndex[A, B](xs: List[A])(f: (A, Int) => Unit) {
var index = 0
var ys = xs
while (!ys.isEmpty) {
f(ys.head, index)
ys = ys.tail
index += 1
}
}
// @inline
final def findOrElse[A](xs: TraversableOnce[A])(p: A => Boolean)(orElse: => A): A = {
xs find p getOrElse orElse
}
final def mapFrom[A, A1 >: A, B](xs: List[A])(f: A => B): Map[A1, B] = {
Map[A1, B](xs map (x => (x, f(x))): _*)
}
final def mapWithIndex[A, B](xs: List[A])(f: (A, Int) => B): List[B] = {
val lb = new ListBuffer[B]
var index = 0
var ys = xs
while (!ys.isEmpty) {
lb += f(ys.head, index)
ys = ys.tail
index += 1
}
lb.toList
}
final def collectMap2[A, B, C](xs1: List[A], xs2: List[B])(p: (A, B) => Boolean): Map[A, B] = {
if (xs1.isEmpty || xs2.isEmpty)
return Map()
val buf = immutable.Map.newBuilder[A, B]
var ys1 = xs1
var ys2 = xs2
while (!ys1.isEmpty && !ys2.isEmpty) {
val x1 = ys1.head
val x2 = ys2.head
if (p(x1, x2))
buf += ((x1, x2))
ys1 = ys1.tail
ys2 = ys2.tail
}
buf.result
}
final def foreach2[A, B](xs1: List[A], xs2: List[B])(f: (A, B) => Unit): Unit = {
var ys1 = xs1
var ys2 = xs2
while (!ys1.isEmpty && !ys2.isEmpty) {
f(ys1.head, ys2.head)
ys1 = ys1.tail
ys2 = ys2.tail
}
}
final def foreach3[A, B, C](xs1: List[A], xs2: List[B], xs3: List[C])(f: (A, B, C) => Unit): Unit = {
var ys1 = xs1
var ys2 = xs2
var ys3 = xs3
while (!ys1.isEmpty && !ys2.isEmpty && !ys3.isEmpty) {
f(ys1.head, ys2.head, ys3.head)
ys1 = ys1.tail
ys2 = ys2.tail
ys3 = ys3.tail
}
}
final def exists2[A, B](xs1: List[A], xs2: List[B])(f: (A, B) => Boolean): Boolean = {
var ys1 = xs1
var ys2 = xs2
while (!ys1.isEmpty && !ys2.isEmpty) {
if (f(ys1.head, ys2.head))
return true
ys1 = ys1.tail
ys2 = ys2.tail
}
false
}
final def forall2[A, B](xs1: List[A], xs2: List[B])(f: (A, B) => Boolean): Boolean = {
var ys1 = xs1
var ys2 = xs2
while (!ys1.isEmpty && !ys2.isEmpty) {
if (!f(ys1.head, ys2.head))
return false
ys1 = ys1.tail
ys2 = ys2.tail
}
true
}
final def forall3[A, B, C](xs1: List[A], xs2: List[B], xs3: List[C])(f: (A, B, C) => Boolean): Boolean = {
var ys1 = xs1
var ys2 = xs2
var ys3 = xs3
while (!ys1.isEmpty && !ys2.isEmpty && !ys3.isEmpty) {
if (!f(ys1.head, ys2.head, ys3.head))
return false
ys1 = ys1.tail
ys2 = ys2.tail
ys3 = ys3.tail
}
true
}
final def transposeSafe[A](ass: List[List[A]]): Option[List[List[A]]] = try {
Some(ass.transpose)
} catch {
case _: IllegalArgumentException => None
}
}
object Collections extends Collections { }
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