diff options
Diffstat (limited to 'compiler/src/dotty/tools/dotc/transform/TreeExtractors.scala')
-rw-r--r-- | compiler/src/dotty/tools/dotc/transform/TreeExtractors.scala | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/compiler/src/dotty/tools/dotc/transform/TreeExtractors.scala b/compiler/src/dotty/tools/dotc/transform/TreeExtractors.scala new file mode 100644 index 000000000..7a5c5df9d --- /dev/null +++ b/compiler/src/dotty/tools/dotc/transform/TreeExtractors.scala @@ -0,0 +1,48 @@ +package dotty.tools.dotc +package transform + +import ast.{Trees, tpd} +import core._, core.Decorators._ +import Contexts._, Flags._, Trees._, Types._, StdNames._, Symbols._ +import ValueClasses._ + +object TreeExtractors { + import tpd._ + + /** Match arg1.op(arg2) and extract (arg1, op.symbol, arg2) */ + object BinaryOp { + def unapply(t: Tree)(implicit ctx: Context): Option[(Tree, Symbol, Tree)] = t match { + case Apply(sel @ Select(arg1, _), List(arg2)) => + Some((arg1, sel.symbol, arg2)) + case _ => + None + } + } + + /** Match new C(args) and extract (C, args) */ + object NewWithArgs { + def unapply(t: Tree)(implicit ctx: Context): Option[(Type, List[Tree])] = t match { + case Apply(Select(New(_), nme.CONSTRUCTOR), args) => + Some((t.tpe, args)) + case _ => + None + } + } + + /** For an instance v of a value class like: + * class V(val underlying: X) extends AnyVal + * Match v.underlying() and extract v + */ + object ValueClassUnbox { + def unapply(t: Tree)(implicit ctx: Context): Option[Tree] = t match { + case Apply(sel @ Select(ref, _), Nil) => + val d = ref.tpe.widenDealias.typeSymbol.denot + if (isDerivedValueClass(d) && (sel.symbol eq valueClassUnbox(d.asClass))) { + Some(ref) + } else + None + case _ => + None + } + } +} |