diff options
Diffstat (limited to 'src/compiler/scala/tools/nsc/typechecker/ContextErrors.scala')
| -rw-r--r-- | src/compiler/scala/tools/nsc/typechecker/ContextErrors.scala | 23 |
1 files changed, 20 insertions, 3 deletions
diff --git a/src/compiler/scala/tools/nsc/typechecker/ContextErrors.scala b/src/compiler/scala/tools/nsc/typechecker/ContextErrors.scala index 7ecc2be9be..2472f63993 100644 --- a/src/compiler/scala/tools/nsc/typechecker/ContextErrors.scala +++ b/src/compiler/scala/tools/nsc/typechecker/ContextErrors.scala @@ -408,11 +408,28 @@ trait ContextErrors { setError(tree) } - def MissingParameterTypeError(fun: Tree, vparam: ValDef, pt: Type) = + def MissingParameterTypeError(fun: Tree, vparam: ValDef, pt: Type, withTupleAddendum: Boolean) = { + def issue(what: String) = { + val addendum: String = fun match { + case Function(params, _) if withTupleAddendum => + val funArity = params.length + val example = analyzer.exampleTuplePattern(params map (_.name)) + (pt baseType FunctionClass(1)) match { + case TypeRef(_, _, arg :: _) if arg.typeSymbol == TupleClass(funArity) && funArity > 1 => + sm"""| + |Note: The expected type requires a one-argument function accepting a $funArity-Tuple. + | Consider a pattern matching anoynmous function, `{ case $example => ... }`""" + case _ => "" + } + case _ => "" + } + issueNormalTypeError(vparam, what + addendum) + } if (vparam.mods.isSynthetic) fun match { case Function(_, Match(_, _)) => MissingParameterTypeAnonMatchError(vparam, pt) - case _ => issueNormalTypeError(vparam, "missing parameter type for expanded function " + fun) - } else issueNormalTypeError(vparam, "missing parameter type") + case _ => issue("missing parameter type for expanded function " + fun) + } else issue("missing parameter type") + } def MissingParameterTypeAnonMatchError(vparam: Tree, pt: Type) = issueNormalTypeError(vparam, "missing parameter type for expanded function\n"+ |