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import scala.reflect.macros.blackbox.Context
abstract class RangeDefault {
val from, to: Int
def foreach(f: Int => Unit) = {
var i = from
while (i < to) { f(i); i += 1 }
}
}
/** This class should go into reflect.macro once it is a bit more stable. */
abstract class Utils {
val context: Context
import context.universe._
import internal._
class TreeSubstituter(from: List[Symbol], to: List[Tree]) extends Transformer {
override def transform(tree: Tree): Tree = tree match {
case Ident(_) =>
def subst(from: List[Symbol], to: List[Tree]): Tree =
if (from.isEmpty) tree
else if (tree.symbol == from.head) to.head.duplicate // TODO: does it ever make sense *not* to perform a shallowDuplicate on `to.head`?
else subst(from.tail, to.tail);
subst(from, to)
case _ =>
val tree1 = super.transform(tree)
if (tree1 ne tree) setType(tree1, null)
tree1
}
}
def makeApply(fn: Tree, args: List[Tree]): Tree = fn match {
case Function(vparams, body) =>
new TreeSubstituter(vparams map (_.symbol), args) transform body
case Block(stats, expr) =>
Block(stats, makeApply(expr, args))
case _ =>
// todo. read the compiler config and print if -Ydebug is set
//println("no beta on "+fn+" "+fn.getClass)
Apply(fn, args)
}
def makeWhile(lname: TermName, cond: Tree, body: Tree): Tree = {
val continu = Apply(Ident(lname), Nil)
val rhs = If(cond, Block(List(body), continu), Literal(Constant()))
LabelDef(lname, Nil, rhs)
}
def makeBinop(left: Tree, op: String, right: Tree): Tree =
Apply(Select(left, TermName(op)), List(right))
}
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