Created
April 29, 2013 13:05
-
-
Save xeno-by/5481456 to your computer and use it in GitHub Desktop.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| import scala.reflect.macros.Context | |
| import language.experimental.macros | |
| object Macros { | |
| implicit class StringContextExtension(ctx: StringContext) { | |
| object split { | |
| def unapply(dummy: Any): Any = macro impl | |
| } | |
| } | |
| def impl(c: Context)(dummy: c.Expr[Any]): c.Expr[Any] = { | |
| import c.universe._ | |
| val Apply(Select(Select(Apply(_, List(Apply(_, statics))), _), _), List(dummy)) = c.macroApplication | |
| val nsplicees = statics.length - 1 | |
| if (nsplicees <= 1) c.abort(c.enclosingPosition, "split needs more than one splicee") | |
| def mkPart(i: Int) = { | |
| if (statics.mkString.contains("into ints: ")) { | |
| Apply(Select(Ident(newTermName("scrut")), newTermName("$div")), List(Literal(Constant(nsplicees)))) | |
| } else if (statics.mkString.contains("into strings: ")) { | |
| val sscrut = Select(Ident(newTermName("scrut")), newTermName("toString")) | |
| val substring = Select(sscrut, newTermName("substring")) | |
| val length = Select(sscrut, newTermName("length")) | |
| val onenth = Apply(Select(length, newTermName("$div")), List(Literal(Constant(nsplicees)))) | |
| val lo = Apply(Select(onenth, "$times"), List(Literal(Constant(i)))) | |
| val hi = Apply(Select(lo, "$plus"), List(Literal(Constant(onenth)))) | |
| Apply(substring, List(lo, hi)) | |
| } else { | |
| ??? | |
| } | |
| } | |
| val scrutinee = ValDef(NoMods, newTermName("scrut"), TypeTree(), dummy) | |
| val partDefs = 1.to(nsplicees).map(i => ValDef(NoMods, newTermName("part" + i), TypeTree(), mkPart(i))).toList | |
| val partRefs = partDefs.map(partDef => Ident(partDef.name)) | |
| val result = Apply(Ident(newTermName("Some")), List(Apply(Ident("Tuple" + nsplicees), partRefs))) | |
| c.Expr[Any](Block(scrutinee +: partDefs, result)) | |
| } | |
| } | |
| import Macros._ | |
| object Test extends App { | |
| 42 match { | |
| case split"into ints: $x and $y" => println((x, y, x.getClass, y.getClass)) | |
| case _ => println("fail") | |
| } | |
| // 42 match { | |
| // case split"into strings: $x and $y" => println((x, y, x.getClass, y.getClass)) | |
| // case _ => println("fail") | |
| // } | |
| } | |
| 15:03 ~/Projects/210x/sandbox (2.10.x)$ scalac Macros.scala && scalac Test.scala | |
| { | |
| val scrut: Int = <unapply-selector>; | |
| val part1: Int = scrut./(2); | |
| val part2: Int = scrut./(2); | |
| scala.Some.apply[(Int, Int)](scala.Tuple2.apply[Int, Int](part1, part2)) | |
| } | |
| Block[1](List(ValDef[2](Modifiers(), newTermName("scrut"), TypeTree[3](), Ident[3](newTermName("<unapply-selector>")#20755)), ValDef[2](Modifiers(), newTermName("part1"), TypeTree[3](), Apply[3](Select[4](Ident[5](newTermName("scrut")#20758), newTermName("$div")#17275), List(Literal[6](Constant(2))))), ValDef[2](Modifiers(), newTermName("part2"), TypeTree[3](), Apply[3](Select[4](Ident[5](newTermName("scrut")#20758), newTermName("$div")#17275), List(Literal[6](Constant(2)))))), Apply[1](TypeApply[7](Select[8](Select[9](Ident[10](scala#20), scala.Some#1309), newTermName("apply")#20794), List(TypeTree[11]())), List(Apply[11](TypeApply[12](Select[13](Select[14](Ident[10](scala#20), scala.Tuple2#1513), newTermName("apply")#19908), List(TypeTree[3](), TypeTree[3]())), List(Ident[3](newTermName("part1")#20759), Ident[3](newTermName("part2")#20760)))))) | |
| [1] TypeRef(ThisType(scala#21), scala.Some#1308, List(TypeRef(ThisType(scala#21), scala.Tuple2#1512, List(TypeRef(ThisType(scala#21), scala.Int#849, List()), TypeRef(ThisType(scala#21), scala.Int#849, List()))))) | |
| [2] NoType | |
| [3] TypeRef(ThisType(scala#21), scala.Int#849, List()) | |
| [4] MethodType(List(newTermName("x")#17276), TypeRef(ThisType(scala#21), scala.Int#849, List())) | |
| [5] SingleType(NoPrefix, newTermName("scrut")#20758) | |
| [6] ConstantType(Constant(2)) | |
| [7] MethodType(List(newTermName("x")#20886), TypeRef(ThisType(scala#21), scala.Some#1308, List(TypeRef(ThisType(scala#21), scala.Tuple2#1512, List(TypeRef(ThisType(scala#21), scala.Int#849, List()), TypeRef(ThisType(scala#21), scala.Int#849, List())))))) | |
| [8] PolyType(List(newTypeName("A")#20795), MethodType(List(newTermName("x")#20796), TypeRef(ThisType(scala#21), scala.Some#1308, List(TypeRef(NoPrefix, newTypeName("A")#20795, List()))))) | |
| [9] SingleType(SingleType(ThisType(<root>#2), scala#20), scala.Some#1309) | |
| [10] SingleType(ThisType(<root>#2), scala#20) | |
| [11] TypeRef(ThisType(scala#21), scala.Tuple2#1512, List(TypeRef(ThisType(scala#21), scala.Int#849, List()), TypeRef(ThisType(scala#21), scala.Int#849, List()))) | |
| [12] MethodType(List(newTermName("_1")#20884, newTermName("_2")#20885), TypeRef(ThisType(scala#21), scala.Tuple2#1512, List(TypeRef(ThisType(scala#21), scala.Int#849, List()), TypeRef(ThisType(scala#21), scala.Int#849, List())))) | |
| [13] PolyType(List(newTypeName("T1")#19909, newTypeName("T2")#19910), MethodType(List(newTermName("_1")#19911, newTermName("_2")#19912), TypeRef(ThisType(scala#21), scala.Tuple2#1512, List(TypeRef(NoPrefix, newTypeName("T1")#19909, List()), TypeRef(NoPrefix, newTypeName("T2")#19910, List()))))) | |
| [14] SingleType(SingleType(ThisType(<root>#2), scala#20), scala.Tuple2#1513) | |
| error: | |
| while compiling: Test.scala | |
| during phase: typer | |
| library version: version 2.10.2-20130425-053916-403ba8938f | |
| compiler version: version 2.10.2-20130425-053916-403ba8938f | |
| reconstructed args: -language:experimental.macros | |
| last tree to typer: Block | |
| symbol: null | |
| symbol definition: null | |
| tpe: Some[(Int, Int)] | |
| symbol owners: | |
| context owners: value <local Test> -> object Test -> package <empty> | |
| == Enclosing template or block == | |
| Template( // val <local Test>: <notype> in object Test | |
| "App" // parents | |
| ValDef( | |
| private | |
| "_" | |
| <tpt> | |
| <empty> | |
| ) | |
| // 2 statements | |
| DefDef( // def <init>(): Test.type in object Test | |
| <method> | |
| "<init>" | |
| [] | |
| List(Nil) | |
| <tpt> // tree.tpe=Test.type | |
| Block( // tree.tpe=Unit | |
| Apply( // def <init>(): Object in class Object, tree.tpe=Object | |
| Test.super."<init>" // def <init>(): Object in class Object, tree.tpe=()Object | |
| Nil | |
| ) | |
| () | |
| ) | |
| ) | |
| Match( | |
| 42 | |
| // 2 cases | |
| CaseDef( | |
| Apply( | |
| StringContext("into ints: ", " and ", "")."split" | |
| // 2 arguments | |
| Bind( | |
| "x" | |
| "_" | |
| ) | |
| Bind( | |
| "y" | |
| "_" | |
| ) | |
| ) | |
| Apply( | |
| "println" | |
| Apply( | |
| "scala"."Tuple4" | |
| // 4 arguments | |
| "x" | |
| "y" | |
| "x"."getClass" | |
| "y"."getClass" | |
| ) | |
| ) | |
| ) | |
| CaseDef( | |
| "_" | |
| Apply( | |
| "println" | |
| "fail" | |
| ) | |
| ) | |
| ) | |
| ) | |
| == Expanded type of tree == | |
| TypeRef( | |
| TypeSymbol( | |
| final case class Some[+A <: <?>] extends Option[A] with Product with Serializable | |
| ) | |
| args = List( | |
| TypeRef( | |
| TypeSymbol( | |
| case class Tuple2[+T1 <: <?>, +T2 <: <?>] extends Product2[T1,T2] with Product with Serializable | |
| ) | |
| args = List( | |
| TypeRef(TypeSymbol(final abstract class Int extends AnyVal)) | |
| TypeRef(TypeSymbol(final abstract class Int extends AnyVal)) | |
| ) | |
| ) | |
| ) | |
| ) | |
| uncaught exception during compilation: java.lang.NullPointerException | |
| error: java.lang.NullPointerException | |
| at scala.tools.nsc.typechecker.Infer$class.extractorFormalTypes(Infer.scala:93) | |
| at scala.tools.nsc.Global$$anon$1.extractorFormalTypes(Global.scala:493) | |
| at scala.tools.nsc.typechecker.Typers$Typer.doTypedUnapply(Typers.scala:3483) | |
| at scala.tools.nsc.typechecker.Typers$Typer.doTypedApply(Typers.scala:3417) | |
| at scala.tools.nsc.typechecker.Typers$Typer.normalTypedApply$1(Typers.scala:4583) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typedApply$1(Typers.scala:4615) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typed1(Typers.scala:5520) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typed(Typers.scala:5598) | |
| at scala.tools.nsc.typechecker.Typers$Typer$$anonfun$119$$anonfun$apply$43.apply(Typers.scala:5712) | |
| at scala.tools.nsc.typechecker.Typers$Typer$$anonfun$119$$anonfun$apply$43.apply(Typers.scala:5712) | |
| at scala.tools.nsc.typechecker.Contexts$Context.withImplicitsDisabledAllowEnrichment(Contexts.scala:232) | |
| at scala.tools.nsc.typechecker.Typers$Typer$$anonfun$119.apply(Typers.scala:5712) | |
| at scala.tools.nsc.typechecker.Typers$Typer$$anonfun$119.apply(Typers.scala:5712) | |
| at scala.tools.nsc.typechecker.TypeDiagnostics$class.typingInPattern(TypeDiagnostics.scala:72) | |
| at scala.tools.nsc.Global$$anon$1.typingInPattern(Global.scala:493) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typedPattern(Typers.scala:5712) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typedCase(Typers.scala:2446) | |
| at scala.tools.nsc.typechecker.Typers$Typer$$anonfun$typedCases$1.apply(Typers.scala:2492) | |
| at scala.tools.nsc.typechecker.Typers$Typer$$anonfun$typedCases$1.apply(Typers.scala:2491) | |
| at scala.collection.immutable.List.loop$1(List.scala:170) | |
| at scala.collection.immutable.List.mapConserve(List.scala:186) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typedCases(Typers.scala:2491) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typedMatch(Typers.scala:2504) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typedVirtualizedMatch$1(Typers.scala:4319) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typed1(Typers.scala:5532) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typed(Typers.scala:5598) | |
| at scala.tools.nsc.typechecker.Typers$Typer.scala$tools$nsc$typechecker$Typers$Typer$$typedStat$1(Typers.scala:2917) | |
| at scala.tools.nsc.typechecker.Typers$Typer$$anonfun$60.apply(Typers.scala:3021) | |
| at scala.tools.nsc.typechecker.Typers$Typer$$anonfun$60.apply(Typers.scala:3021) | |
| at scala.collection.immutable.List.loop$1(List.scala:170) | |
| at scala.collection.immutable.List.mapConserve(List.scala:186) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typedStats(Typers.scala:3021) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typedTemplate(Typers.scala:1910) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typedModuleDef(Typers.scala:1791) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typed1(Typers.scala:5540) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typed(Typers.scala:5598) | |
| at scala.tools.nsc.typechecker.Typers$Typer.scala$tools$nsc$typechecker$Typers$Typer$$typedStat$1(Typers.scala:2917) | |
| at scala.tools.nsc.typechecker.Typers$Typer$$anonfun$60.apply(Typers.scala:3021) | |
| at scala.tools.nsc.typechecker.Typers$Typer$$anonfun$60.apply(Typers.scala:3021) | |
| at scala.collection.immutable.List.loop$1(List.scala:170) | |
| at scala.collection.immutable.List.mapConserve(List.scala:186) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typedStats(Typers.scala:3021) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typedPackageDef$1(Typers.scala:5257) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typed1(Typers.scala:5543) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typed(Typers.scala:5598) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typed(Typers.scala:5655) | |
| at scala.tools.nsc.typechecker.Analyzer$typerFactory$$anon$3.apply(Analyzer.scala:99) | |
| at scala.tools.nsc.Global$GlobalPhase.applyPhase(Global.scala:464) | |
| at scala.tools.nsc.typechecker.Analyzer$typerFactory$$anon$3$$anonfun$run$1.apply(Analyzer.scala:91) | |
| at scala.tools.nsc.typechecker.Analyzer$typerFactory$$anon$3$$anonfun$run$1.apply(Analyzer.scala:91) | |
| at scala.collection.Iterator$class.foreach(Iterator.scala:727) | |
| at scala.collection.AbstractIterator.foreach(Iterator.scala:1157) | |
| at scala.tools.nsc.typechecker.Analyzer$typerFactory$$anon$3.run(Analyzer.scala:91) | |
| at scala.tools.nsc.Global$Run.compileUnitsInternal(Global.scala:1583) | |
| at scala.tools.nsc.Global$Run.compileUnits(Global.scala:1557) | |
| at scala.tools.nsc.Global$Run.compileSources(Global.scala:1553) | |
| at scala.tools.nsc.Global$Run.compile(Global.scala:1662) | |
| at scala.tools.nsc.Driver.doCompile(Driver.scala:33) | |
| at scala.tools.nsc.Main$.doCompile(Main.scala:79) | |
| at scala.tools.nsc.Driver.process(Driver.scala:54) | |
| at scala.tools.nsc.Driver.main(Driver.scala:67) | |
| at scala.tools.nsc.Main.main(Main.scala) | |
| Exception in thread "main" java.lang.NullPointerException | |
| at scala.tools.nsc.typechecker.Infer$class.extractorFormalTypes(Infer.scala:93) | |
| at scala.tools.nsc.Global$$anon$1.extractorFormalTypes(Global.scala:493) | |
| at scala.tools.nsc.typechecker.Typers$Typer.doTypedUnapply(Typers.scala:3483) | |
| at scala.tools.nsc.typechecker.Typers$Typer.doTypedApply(Typers.scala:3417) | |
| at scala.tools.nsc.typechecker.Typers$Typer.normalTypedApply$1(Typers.scala:4583) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typedApply$1(Typers.scala:4615) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typed1(Typers.scala:5520) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typed(Typers.scala:5598) | |
| at scala.tools.nsc.typechecker.Typers$Typer$$anonfun$119$$anonfun$apply$43.apply(Typers.scala:5712) | |
| at scala.tools.nsc.typechecker.Typers$Typer$$anonfun$119$$anonfun$apply$43.apply(Typers.scala:5712) | |
| at scala.tools.nsc.typechecker.Contexts$Context.withImplicitsDisabledAllowEnrichment(Contexts.scala:232) | |
| at scala.tools.nsc.typechecker.Typers$Typer$$anonfun$119.apply(Typers.scala:5712) | |
| at scala.tools.nsc.typechecker.Typers$Typer$$anonfun$119.apply(Typers.scala:5712) | |
| at scala.tools.nsc.typechecker.TypeDiagnostics$class.typingInPattern(TypeDiagnostics.scala:72) | |
| at scala.tools.nsc.Global$$anon$1.typingInPattern(Global.scala:493) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typedPattern(Typers.scala:5712) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typedCase(Typers.scala:2446) | |
| at scala.tools.nsc.typechecker.Typers$Typer$$anonfun$typedCases$1.apply(Typers.scala:2492) | |
| at scala.tools.nsc.typechecker.Typers$Typer$$anonfun$typedCases$1.apply(Typers.scala:2491) | |
| at scala.collection.immutable.List.loop$1(List.scala:170) | |
| at scala.collection.immutable.List.mapConserve(List.scala:186) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typedCases(Typers.scala:2491) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typedMatch(Typers.scala:2504) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typedVirtualizedMatch$1(Typers.scala:4319) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typed1(Typers.scala:5532) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typed(Typers.scala:5598) | |
| at scala.tools.nsc.typechecker.Typers$Typer.scala$tools$nsc$typechecker$Typers$Typer$$typedStat$1(Typers.scala:2917) | |
| at scala.tools.nsc.typechecker.Typers$Typer$$anonfun$60.apply(Typers.scala:3021) | |
| at scala.tools.nsc.typechecker.Typers$Typer$$anonfun$60.apply(Typers.scala:3021) | |
| at scala.collection.immutable.List.loop$1(List.scala:170) | |
| at scala.collection.immutable.List.mapConserve(List.scala:186) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typedStats(Typers.scala:3021) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typedTemplate(Typers.scala:1910) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typedModuleDef(Typers.scala:1791) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typed1(Typers.scala:5540) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typed(Typers.scala:5598) | |
| at scala.tools.nsc.typechecker.Typers$Typer.scala$tools$nsc$typechecker$Typers$Typer$$typedStat$1(Typers.scala:2917) | |
| at scala.tools.nsc.typechecker.Typers$Typer$$anonfun$60.apply(Typers.scala:3021) | |
| at scala.tools.nsc.typechecker.Typers$Typer$$anonfun$60.apply(Typers.scala:3021) | |
| at scala.collection.immutable.List.loop$1(List.scala:170) | |
| at scala.collection.immutable.List.mapConserve(List.scala:186) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typedStats(Typers.scala:3021) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typedPackageDef$1(Typers.scala:5257) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typed1(Typers.scala:5543) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typed(Typers.scala:5598) | |
| at scala.tools.nsc.typechecker.Typers$Typer.typed(Typers.scala:5655) | |
| at scala.tools.nsc.typechecker.Analyzer$typerFactory$$anon$3.apply(Analyzer.scala:99) | |
| at scala.tools.nsc.Global$GlobalPhase.applyPhase(Global.scala:464) | |
| at scala.tools.nsc.typechecker.Analyzer$typerFactory$$anon$3$$anonfun$run$1.apply(Analyzer.scala:91) | |
| at scala.tools.nsc.typechecker.Analyzer$typerFactory$$anon$3$$anonfun$run$1.apply(Analyzer.scala:91) | |
| at scala.collection.Iterator$class.foreach(Iterator.scala:727) | |
| at scala.collection.AbstractIterator.foreach(Iterator.scala:1157) | |
| at scala.tools.nsc.typechecker.Analyzer$typerFactory$$anon$3.run(Analyzer.scala:91) | |
| at scala.tools.nsc.Global$Run.compileUnitsInternal(Global.scala:1583) | |
| at scala.tools.nsc.Global$Run.compileUnits(Global.scala:1557) | |
| at scala.tools.nsc.Global$Run.compileSources(Global.scala:1553) | |
| at scala.tools.nsc.Global$Run.compile(Global.scala:1662) | |
| at scala.tools.nsc.Driver.doCompile(Driver.scala:33) | |
| at scala.tools.nsc.Main$.doCompile(Main.scala:79) | |
| at scala.tools.nsc.Driver.process(Driver.scala:54) | |
| at scala.tools.nsc.Driver.main(Driver.scala:67) | |
| at scala.tools.nsc.Main.main(Main.scala) |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment