/* __ *\ ** ________ ___ / / ___ Scala API ** ** / __/ __// _ | / / / _ | (c) 2002-2009, LAMP/EPFL ** ** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ ** ** /____/\___/_/ |_/____/_/ | | ** ** |/ ** \* */ // $Id$ /**

* This program generates the ProductN, TupleN FunctionN classes, where * 0 <= N <+ MAXWIDTH. *

*

* usage: scala -classpath ... genprod PATH * where PATH is the desired output directory *

* * @author Burak Emir, Stephane Micheloud, Geoffrey Washburn, Paul Phillips * @version 1.1 */ object genprod { val MAX_ARITY = 22 def arities = (1 to MAX_ARITY).toList class Group(val name: String) { def className(i: Int) = name + i def fileName(i: Int) = className(i) + ".scala" } def productFiles = arities map Product.make def tupleFiles = arities map Tuple.make def functionFiles = (0 :: arities) map Function.make def allfiles = productFiles ::: tupleFiles ::: functionFiles trait Arity extends Group { def i: Int // arity def typeArgsString(xs: Seq[String]) = xs.mkString("[", ", ", "]") def to = (1 to i).toList def s = if (i == 1) "" else "s" def className = name + i def fileName = className + ".scala" def targs = to map ("T" + _) def vdefs = to map ("v" + _) def xdefs = to map ("x" + _) def mdefs = to map ("_" + _) def invariantArgs = typeArgsString(targs) def covariantArgs = typeArgsString(targs map ("+" + _)) def contraCoArgs = typeArgsString((targs map ("-" + _)) ::: List("+R")) def fields = List.map2(mdefs, targs)(_ + ":" + _) mkString "," def funArgs = List.map2(vdefs, targs)(_ + ":" + _) mkString "," def genprodString = "// generated by genprod on %s %s %s".format(now, withFancy, withMoreMethods) def now = new java.util.Date().toString() def moreMethods = "" def descriptiveComment = "" def withFancy = if (descriptiveComment.isEmpty) "" else "(with fancy comment)" def withMoreMethods = if (moreMethods.isEmpty) "" else "(with extra methods)" def header = """ /* __ *\ ** ________ ___ / / ___ Scala API ** ** / __/ __// _ | / / / _ | (c) 2002-2009, LAMP/EPFL ** ** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ ** ** /____/\___/_/ |_/____/_/ | | ** ** |/ ** \* */ // $Id$ %s package scala """.trim.format(genprodString) + "\n\n" } def main(args: Array[String]) { if (args.length != 1) { println("please give path of output directory") exit(-1) } val out = args(0) def writeFile(node: scala.xml.Node) { import java.io.{File, FileOutputStream} import java.nio.channels.Channels val f = new File(out, node.attributes("name").toString) try { f.createNewFile val fos = new FileOutputStream(f) val c = fos.getChannel val w = Channels.newWriter(c, "utf-8") w.write(node.text) w.close } catch { case e: java.io.IOException => println(e.getMessage() + ": " + out) exit(-1) } } allfiles foreach writeFile } } import genprod._ /* zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz F U N C T I O N zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz */ object FunctionZero extends Function(0) { override def descriptiveComment = functionNTemplate.format("currentSeconds", "anonfun0", """ * * val currentSeconds = () => System.currentTimeMillis() / 1000L * * val anonfun0 = new Function0[Long] { * def apply(): Long = System.currentTimeMillis() / 1000L * } * * println(currentSeconds()) * println(anonfun0())""") override def moreMethods = "" } object FunctionOne extends Function(1) { override def descriptiveComment = functionNTemplate.format("succ", "anonfun1", """ * * val succ = (x: Int) => x + 1 * * val anonfun1 = new Function1[Int, Int] { * def apply(x: Int): Int = x + 1 * } * * println(succ(0)) * println(anonfun1(0))""") override def moreMethods = """ /** (f compose g)(x) == f(g(x)) */ def compose[A](g: A => T1): A => R = { x => apply(g(x)) } /** (f andThen g)(x) == g(f(x)) */ def andThen[A](g: R => A): T1 => A = { x => g(apply(x)) } """ } object FunctionTwo extends Function(2) { override def descriptiveComment = functionNTemplate.format("max", "anonfun2", """ * * val max = (x: Int, y: Int) => if (x < y) y else x * * val anonfun2 = new Function2[Int, Int, Int] { * def apply(x: Int, y: Int): Int = if (x < y) y else x * } * * println(max(0, 1)) * println(anonfun2(0, 1))""") } object Function { def make(i: Int) = apply(i)() def apply(i: Int) = i match { case 0 => FunctionZero case 1 => FunctionOne case 2 => FunctionTwo case _ => new Function(i) } } class Function(val i: Int) extends Group("Function") with Arity { val functionNTemplate = """

* In the following example the definition of * %s is a shorthand for the anonymous class * definition %s: *

*
 *  object Main extends Application {
%s
 *  }
""" def toStr() = "\"" + ("" format i) + "\"" def apply() = { {header} /** <p> * Function with {i} parameter{s}. * </p> * {descriptiveComment} */ trait {className}{contraCoArgs} extends AnyRef {{ self => def apply({funArgs}): R override def toString() = {toStr} {moreMethods} }} } // (x1: T1) => (x2: T2) => (x3: T3) => (x4: T4) => apply(x1,x2,x3,x4) def shortCurry = { val body = xdefs.mkString("apply(", ",", ")") List.map2(xdefs, targs)("(%s: %s) => ".format(_, _)).mkString("", "", body) } // (x1: T1) => ((x2: T2, x3: T3, x4: T4, x5: T5, x6: T6, x7: T7) => self.apply(x1,x2,x3,x4,x5,x6,x7)).curry def longCurry = (List.map2(xdefs, targs)(_ + ": " + _) drop 1).mkString( "(x1: T1) => ((", ", ", ") => self.apply(%s)).curry".format(xdefs mkString ",") ) // f(x1,x2,x3,x4,x5,x6) == (f.curry)(x1)(x2)(x3)(x4)(x5)(x6) def curryComment = { """ /** f(%s) == (f.curry)%s */ """.format(xdefs mkString ",", xdefs map ("(" + _ + ")") mkString) } def curryMethod = { val body = if (i < 5) shortCurry else longCurry " def curry: %s => R = {\n %s\n }\n".format( targs mkString " => ", body ) } override def moreMethods = curryComment + curryMethod } // object Function /* zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz T U P L E zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz */ object Tuple { def make(i: Int) = apply(i)() def apply(i: Int) = i match { case 2 => TupleTwo case _ => new Tuple(i) } } object TupleTwo extends Tuple(2) { override def moreMethods = """ /** Swap the elements of the tuple */ def swap: Tuple2[T2,T1] = Tuple2(_2, _1) """ } class Tuple(val i: Int) extends Group("Tuple") with Arity { // prettifies it a little if it's overlong def mkToString() = { def str(xs: List[String]) = xs.mkString(""" + "," + """) if (i <= MAX_ARITY / 2) str(mdefs) else { val s1 = str(mdefs take (i / 2)) val s2 = str(mdefs drop (i / 2)) s1 + " +\n \",\" + " + s2 } } def apply() = { {header} /** {className} is the canonical representation of a @see {Product.className(i)} * {descriptiveComment} */ case class {className}{covariantArgs}({fields}) extends {Product.className(i)}{invariantArgs} {{ override def toString() = "(" + {mkToString} + ")" {moreMethods} }} } } // object Tuple /* zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz P R O D U C T zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz */ object Product extends Group("Product") { def make(i: Int) = apply(i)() def apply(i: Int) = new Product(i) } class Product(val i: Int) extends Group("Product") with Arity { def cases = { val xs = for ((x, i) <- mdefs.zipWithIndex) yield "case %d => %s".format(i, x) val default = "case _ => throw new IndexOutOfBoundsException(n.toString())" "\n" + ((xs ::: List(default)) map (" " + _ + "\n") mkString) } def proj = { List.map2(mdefs, targs)( " /** projection of this product */\n def %s: %s\n\n".format(_, _) ) mkString } def apply() = { {header} object {className} {{ def unapply{invariantArgs}(x: {className}{invariantArgs}): Option[{className}{invariantArgs}] = Some(x) }} /** {className} is a cartesian product of {i} component{s}. * {descriptiveComment} * @since 2.3 */ trait {className}{covariantArgs} extends Product {{ /** * The arity of this product. * @return {i} */ override def productArity = {i} /** * Returns the n-th projection of this product if 0&lt;=n&lt;arity, * otherwise null. * * @param n number of the projection to be returned * @return same as _(n+1) * @throws IndexOutOfBoundsException */ @throws(classOf[IndexOutOfBoundsException]) override def productElement(n: Int) = n match {{ {cases} }} {proj} {moreMethods} }} } }