org.json4s.ScalaSigReader.scala Maven / Gradle / Ivy
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/*
* Copyright 2009-2010 WorldWide Conferencing, LLC
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.json4s
import scala.tools.scalap.scalax.rules.scalasig._
import scalashim._
object ScalaSigReader {
def readConstructor(argName: String, clazz: Class[_], typeArgIndex: Int, argNames: List[String]): Class[_] = {
val cl = findClass(clazz)
val cstr = findConstructor(cl, argNames).getOrElse(Meta.fail("Can't find constructor for " + clazz))
findArgType(cstr, argNames.indexOf(argName), typeArgIndex)
}
def readField(name: String, clazz: Class[_], typeArgIndex: Int): Class[_] = {
def read(current: Class[_]): MethodSymbol = {
if (current == null)
Meta.fail("Can't find field " + name + " from " + clazz)
else
findField(findClass(current), name).getOrElse(read(current.getSuperclass))
}
findArgTypeForField(read(clazz), typeArgIndex)
}
private def findClass(clazz: Class[_]): ClassSymbol = {
val sig = findScalaSig(clazz).getOrElse(Meta.fail("Can't find ScalaSig for " + clazz))
findClass(sig, clazz).getOrElse(Meta.fail("Can't find " + clazz + " from parsed ScalaSig"))
}
private def findClass(sig: ScalaSig, clazz: Class[_]): Option[ClassSymbol] = {
sig.symbols.collect { case c: ClassSymbol if !c.isModule => c }.find(_.name == clazz.getSimpleName).orElse {
sig.topLevelClasses.find(_.symbolInfo.name == clazz.getSimpleName).orElse {
sig.topLevelObjects.map { obj =>
val t = obj.infoType.asInstanceOf[TypeRefType]
t.symbol.children collect { case c: ClassSymbol => c } find(_.symbolInfo.name == clazz.getSimpleName)
}.head
}
}
}
private def findConstructor(c: ClassSymbol, argNames: List[String]): Option[MethodSymbol] = {
val ms = c.children collect {
case m: MethodSymbol if m.name == "" => m
}
ms.find(m => m.children.map(_.name) == argNames)
}
private def findField(c: ClassSymbol, name: String): Option[MethodSymbol] =
(c.children collect { case m: MethodSymbol if m.name == name => m }).headOption
private def findArgType(s: MethodSymbol, argIdx: Int, typeArgIndex: Int): Class[_] = {
def findPrimitive(t: Type): Symbol = t match {
case TypeRefType(ThisType(_), symbol, _) if isPrimitive(symbol) => symbol
case TypeRefType(_, _, TypeRefType(ThisType(_), symbol, _) :: xs) => symbol
case TypeRefType(_, symbol, Nil) => symbol
case TypeRefType(_, _, args) if typeArgIndex >= args.length => findPrimitive(args(0))
case TypeRefType(_, _, args) =>
args(typeArgIndex) match {
case ref @ TypeRefType(_, _, _) => findPrimitive(ref)
case x => Meta.fail("Unexpected type info " + x)
}
case x => Meta.fail("Unexpected type info " + x)
}
toClass(findPrimitive(s.children(argIdx).asInstanceOf[SymbolInfoSymbol].infoType))
}
private def findArgTypeForField(s: MethodSymbol, typeArgIdx: Int): Class[_] = {
// FIXME can be removed when 2.8 no longer needs to be supported.
// 2.8 does not have NullaryMethodType, work around that.
/*
val t = s.infoType match {
case NullaryMethodType(TypeRefType(_, _, args)) => args(typeArgIdx)
}
*/
def resultType = try {
s.infoType.asInstanceOf[{ def resultType: Type }].resultType
} catch {
case e: java.lang.NoSuchMethodException => s.infoType.asInstanceOf[{ def typeRef: Type }].typeRef
}
val t = resultType match {
case TypeRefType(_, _, args) => args(typeArgIdx)
}
def findPrimitive(t: Type): Symbol = t match {
case TypeRefType(ThisType(_), symbol, _) => symbol
case ref @ TypeRefType(_, _, _) => findPrimitive(ref)
case x => Meta.fail("Unexpected type info " + x)
}
toClass(findPrimitive(t))
}
private def toClass(s: Symbol) = s.path match {
case "scala.Short" => classOf[Short]
case "scala.Int" => classOf[Int]
case "scala.Long" => classOf[Long]
case "scala.Boolean" => classOf[Boolean]
case "scala.Float" => classOf[Float]
case "scala.Double" => classOf[Double]
case _ => classOf[AnyRef]
}
private def isPrimitive(s: Symbol) = toClass(s) != classOf[AnyRef]
private def findScalaSig(clazz: Class[_]): Option[ScalaSig] =
ScalaSigParser.parse(clazz).orElse(findScalaSig(clazz.getDeclaringClass))
// def typeRefType(ms: MethodSymbol): TypeRefType = ms.infoType match {
// case PolyType(tr @ TypeRefType(_, _, _), _) => tr
// case NullaryMethodType(tr @ TypeRefType(_, _, _)) => tr
// case NullaryMethodType(ExistentialType(tr @ TypeRefType(_, _, _), _)) => tr
// }
val ModuleFieldName = "MODULE$"
val ClassLoaders = Vector(this.getClass.getClassLoader)
def companionClass(clazz: Class[_], classLoaders: Iterable[ClassLoader]) = {
val path = if (clazz.getName.endsWith("$")) clazz.getName else "%s$".format(clazz.getName)
val c = resolveClass(path, classLoaders)
if (c.isDefined) c.get else sys.error("Could not resolve clazz='%s'".format(path))
}
def companionObject(clazz: Class[_], classLoaders: Iterable[ClassLoader]) =
companionClass(clazz, classLoaders).getField(ModuleFieldName).get(null)
def companions(t: java.lang.reflect.Type) = {
val k = Meta.rawClassOf(t)
val cc = companionClass(k, ClassLoaders)
(cc, cc.getField(ModuleFieldName).get(null))
}
def resolveClass[X <: AnyRef](c: String, classLoaders: Iterable[ClassLoader]): Option[Class[X]] = classLoaders match {
case Nil => sys.error("resolveClass: expected 1+ classloaders but received empty list")
case List(cl) => Some(Class.forName(c, true, cl).asInstanceOf[Class[X]])
case many => {
try {
var clazz: Class[_] = null
val iter = many.iterator
while (clazz == null && iter.hasNext) {
try {
clazz = Class.forName(c, true, iter.next())
}
catch {
case e: ClassNotFoundException => // keep going, maybe it's in the next one
}
}
if (clazz != null) Some(clazz.asInstanceOf[Class[X]]) else None
}
catch {
case _ => None
}
}
}
}