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| import scala.reflect.macros.blackbox.Context | |
| import language.experimental.macros | |
| object Applicative { | |
| def apply[T](t: T): Option[T] = macro Applicative.impl[T] | |
| def impl[T: c.WeakTypeTag](c: Context)(t: c.Expr[T]): c.Expr[Option[T]] = { | |
| import c.universe._ | |
| def rec(t: Tree): Iterator[c.Tree] = Iterator(t) ++ t.children.flatMap(rec(_)) | |
| val bound = collection.mutable.Buffer.empty[(c.Tree, ValDef)] | |
| val defsWithinMacro = rec(t.tree).filter(_.isDef).map(_.symbol).toSet | |
| val transformed = c.internal.typingTransform(t.tree) { | |
| case (t @ q"$fun.get", api) if fun.tpe <:< c.typeOf[Option[_]] => | |
| val defsWithinGet = rec(fun).filter(_.isDef).map(_.symbol).toSet | |
| val used = rec(t) | |
| val banned = used.filter(x => | |
| defsWithinMacro(x.symbol) && !defsWithinGet(x.symbol) | |
| ) | |
| if (banned.hasNext){ | |
| val banned0 = banned.next() | |
| c.abort(banned0.pos, "cannot apply() value defined within the T{...} block") | |
| } | |
| val tempName = c.freshName(TermName("tmp")) | |
| val tempSym = c.internal.newTermSymbol(api.currentOwner, tempName) | |
| c.internal.setInfo(tempSym, t.tpe) | |
| val tempIdent = Ident(tempSym) | |
| c.internal.setType(tempIdent, t.tpe) | |
| bound.append((fun, c.internal.valDef(tempSym))) | |
| tempIdent | |
| case (t, api) => api.default(t) | |
| } | |
| val (exprs, bindings) = bound.unzip | |
| c.Expr[Option[T]](q"${exprs(0)}.map{ (${c.untypecheck(bindings(0))}) => $transformed }") | |
| } | |
| } |
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| @ Applicative{ (() => Some(1).get)() } | |
| java.util.NoSuchElementException: value tmp$macro$1 | |
| at scala.collection.mutable.AnyRefMap$ExceptionDefault.apply(AnyRefMap.scala:425) | |
| at scala.collection.mutable.AnyRefMap$ExceptionDefault.apply(AnyRefMap.scala:424) | |
| at scala.collection.mutable.AnyRefMap.apply(AnyRefMap.scala:180) | |
| at scala.tools.nsc.backend.jvm.BCodeSkelBuilder$PlainSkelBuilder$locals$.load(BCodeSkelBuilder.scala:389) | |
| at scala.tools.nsc.backend.jvm.BCodeBodyBuilder$PlainBodyBuilder.genLoad(BCodeBodyBuilder.scala:354) | |
| at scala.tools.nsc.backend.jvm.BCodeBodyBuilder$PlainBodyBuilder.$anonfun$genLoadArguments$1(BCodeBodyBuilder.scala:935) | |
| at scala.tools.nsc.backend.jvm.BCodeBodyBuilder$PlainBodyBuilder.genLoadArguments(BCodeBodyBuilder.scala:935) | |
| at scala.tools.nsc.backend.jvm.BCodeBodyBuilder$PlainBodyBuilder.genApply(BCodeBodyBuilder.scala:628) | |
| at scala.tools.nsc.backend.jvm.BCodeBodyBuilder$PlainBodyBuilder.genLoad(BCodeBodyBuilder.scala:296) | |
| at scala.tools.nsc.backend.jvm.BCodeBodyBuilder$PlainBodyBuilder.genBlock(BCodeBodyBuilder.scala:813) | |
| at scala.tools.nsc.backend.jvm.BCodeBodyBuilder$PlainBodyBuilder.genLoad(BCodeBodyBuilder.scala:366) | |
| at scala.tools.nsc.backend.jvm.BCodeBodyBuilder$PlainBodyBuilder.$anonfun$genLoadArguments$1(BCodeBodyBuilder.scala:935) | |
| at scala.tools.nsc.backend.jvm.BCodeBodyBuilder$PlainBodyBuilder.genLoadArguments(BCodeBodyBuilder.scala:935) | |
| at scala.tools.nsc.backend.jvm.BCodeBodyBuilder$PlainBodyBuilder.genApply(BCodeBodyBuilder.scala:665) | |
| at scala.tools.nsc.backend.jvm.BCodeBodyBuilder$PlainBodyBuilder.genLoad(BCodeBodyBuilder.scala:296) | |
| at scala.tools.nsc.backend.jvm.BCodeSkelBuilder$PlainSkelBuilder.emitNormalMethodBody$1(BCodeSkelBuilder.scala:601) | |
| at scala.tools.nsc.backend.jvm.BCodeSkelBuilder$PlainSkelBuilder.genDefDef(BCodeSkelBuilder.scala:633) | |
| at scala.tools.nsc.backend.jvm.BCodeSkelBuilder$PlainSkelBuilder.gen(BCodeSkelBuilder.scala:507) | |
| at scala.tools.nsc.backend.jvm.BCodeSkelBuilder$PlainSkelBuilder.$anonfun$gen$7(BCodeSkelBuilder.scala:509) | |
| at scala.tools.nsc.backend.jvm.BCodeSkelBuilder$PlainSkelBuilder.gen(BCodeSkelBuilder.scala:509) | |
| at scala.tools.nsc.backend.jvm.BCodeSkelBuilder$PlainSkelBuilder.genPlainClass(BCodeSkelBuilder.scala:110) | |
| at scala.tools.nsc.backend.jvm.CodeGen.genClass(CodeGen.scala:56) | |
| at scala.tools.nsc.backend.jvm.CodeGen.genClassDef$1(CodeGen.scala:26) | |
| at scala.tools.nsc.backend.jvm.CodeGen.genClassDefs$1(CodeGen.scala:44) | |
| at scala.tools.nsc.backend.jvm.CodeGen.$anonfun$genUnit$2(CodeGen.scala:43) | |
| at scala.tools.nsc.backend.jvm.CodeGen.genClassDefs$1(CodeGen.scala:43) | |
| at scala.tools.nsc.backend.jvm.CodeGen.$anonfun$genUnit$2(CodeGen.scala:43) | |
| at scala.tools.nsc.backend.jvm.CodeGen.genClassDefs$1(CodeGen.scala:43) | |
| at scala.tools.nsc.backend.jvm.CodeGen.genUnit(CodeGen.scala:47) | |
| at scala.tools.nsc.backend.jvm.GenBCode$BCodePhase.$anonfun$apply$1(GenBCode.scala:43) | |
| at scala.tools.nsc.backend.jvm.GenBCode$BCodePhase.apply(GenBCode.scala:43) | |
| at scala.tools.nsc.Global$GlobalPhase.$anonfun$applyPhase$1(Global.scala:436) | |
| at scala.tools.nsc.Global$GlobalPhase.applyPhase(Global.scala:429) | |
| at scala.tools.nsc.Global$GlobalPhase.$anonfun$run$1(Global.scala:400) | |
| at scala.tools.nsc.Global$GlobalPhase.$anonfun$run$1$adapted(Global.scala:400) | |
| at scala.collection.Iterator.foreach(Iterator.scala:929) | |
| at scala.collection.Iterator.foreach$(Iterator.scala:929) | |
| at scala.collection.AbstractIterator.foreach(Iterator.scala:1417) | |
| at scala.tools.nsc.Global$GlobalPhase.run(Global.scala:400) | |
| at scala.tools.nsc.backend.jvm.GenBCode$BCodePhase.super$run(GenBCode.scala:53) | |
| at scala.tools.nsc.backend.jvm.GenBCode$BCodePhase.$anonfun$run$1(GenBCode.scala:53) | |
| at scala.tools.nsc.backend.jvm.GenBCode$BCodePhase.run(GenBCode.scala:51) | |
| at scala.tools.nsc.Global$Run.compileUnitsInternal(Global.scala:1452) | |
| at scala.tools.nsc.Global$Run.compileUnits(Global.scala:1436) | |
| at scala.tools.nsc.Global$Run.compileSources(Global.scala:1429) | |
| at scala.tools.nsc.Global$Run.compileFiles(Global.scala:1530) | |
| at ammonite.interp.Compiler$$anon$2.compile(Compiler.scala:320) | |
| at ammonite.interp.CompilerLifecycleManager.compileClass(CompilerLifecycleManager.scala:127) | |
| at ammonite.interp.Interpreter.$anonfun$evaluateLine$1(Interpreter.scala:246) | |
| at ammonite.util.Catching.flatMap(Res.scala:114) | |
| at ammonite.interp.Interpreter.evaluateLine(Interpreter.scala:242) | |
| at ammonite.interp.Interpreter.$anonfun$processLine$5(Interpreter.scala:229) | |
| at ammonite.util.Res$Success.flatMap(Res.scala:61) | |
| at ammonite.interp.Interpreter.$anonfun$processLine$3(Interpreter.scala:214) | |
| at ammonite.util.Res$Success.flatMap(Res.scala:61) | |
| at ammonite.interp.Interpreter.$anonfun$processLine$1(Interpreter.scala:208) | |
| at ammonite.util.Catching.flatMap(Res.scala:114) | |
| at ammonite.interp.Interpreter.processLine(Interpreter.scala:207) | |
| at ammonite.repl.Repl.$anonfun$action$7(Repl.scala:161) | |
| at ammonite.repl.Scoped.$anonfun$flatMap$1(Signaller.scala:43) | |
| at ammonite.repl.Signaller.apply(Signaller.scala:28) | |
| at ammonite.repl.Scoped.flatMap(Signaller.scala:43) | |
| at ammonite.repl.Scoped.flatMap$(Signaller.scala:43) | |
| at ammonite.repl.Signaller.flatMap(Signaller.scala:11) | |
| at ammonite.repl.Repl.$anonfun$action$5(Repl.scala:153) | |
| at ammonite.util.Res$Success.flatMap(Res.scala:61) | |
| at ammonite.repl.Repl.$anonfun$action$1(Repl.scala:140) | |
| at ammonite.util.Catching.flatMap(Res.scala:114) | |
| at ammonite.repl.Repl.action(Repl.scala:132) | |
| at ammonite.repl.Repl.loop$1(Repl.scala:172) | |
| at ammonite.repl.Repl.run(Repl.scala:188) | |
| at ammonite.Main.$anonfun$run$2(Main.scala:194) | |
| at scala.Option.getOrElse(Option.scala:121) | |
| at ammonite.Main.run(Main.scala:181) | |
| at ammonite.MainRunner.$anonfun$runRepl$1(Main.scala:363) | |
| at ammonite.MainRunner.watchLoop(Main.scala:344) | |
| at ammonite.MainRunner.runRepl(Main.scala:363) | |
| at ammonite.Main$.main0(Main.scala:280) | |
| at ammonite.Main$.main(Main.scala:244) | |
| at ammonite.Main.main(Main.scala) |
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