diff options
Diffstat (limited to 'compiler/src/dotty/tools/dotc/typer/Applications.scala')
-rw-r--r-- | compiler/src/dotty/tools/dotc/typer/Applications.scala | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/compiler/src/dotty/tools/dotc/typer/Applications.scala b/compiler/src/dotty/tools/dotc/typer/Applications.scala index 2f2af9868..c4d3e2292 100644 --- a/compiler/src/dotty/tools/dotc/typer/Applications.scala +++ b/compiler/src/dotty/tools/dotc/typer/Applications.scala @@ -48,13 +48,15 @@ object Applications { ref.info.widenExpr.dealias } + def canProductMatch(tp: Type)(implicit ctx: Context) = + extractorMemberType(tp, nme._1).exists + /** Does `tp` fit the "product match" conditions as an unapply result type - * for a pattern with `numArgs` subpatterns> - * This is the case of `tp` is a subtype of the Product<numArgs> class. + * for a pattern with `numArgs` subpatterns? + * This is the case of `tp` has members `_1` to `_N` where `N == numArgs`. */ def isProductMatch(tp: Type, numArgs: Int)(implicit ctx: Context) = - 0 <= numArgs && numArgs <= Definitions.MaxTupleArity && - tp.derivesFrom(defn.ProductNType(numArgs).typeSymbol) + numArgs > 0 && productArity(tp) == numArgs /** Does `tp` fit the "get match" conditions as an unapply result type? * This is the case of `tp` has a `get` member as well as a @@ -69,6 +71,9 @@ object Applications { sels.takeWhile(_.exists).toList } + def productArity(tp: Type)(implicit ctx: Context) = + if (canProductMatch(tp)) productSelectorTypes(tp).size else -1 + def productSelectors(tp: Type)(implicit ctx: Context): List[Symbol] = { val sels = for (n <- Iterator.from(0)) yield tp.member(nme.selectorName(n)).symbol sels.takeWhile(_.exists).toList @@ -109,7 +114,7 @@ object Applications { getUnapplySelectors(getTp, args, pos) else if (unapplyResult isRef defn.BooleanClass) Nil - else if (defn.isProductSubType(unapplyResult)) + else if (canProductMatch(unapplyResult)) productSelectorTypes(unapplyResult) // this will cause a "wrong number of arguments in pattern" error later on, // which is better than the message in `fail`. |