Open Radar

 
Summary:
Compiling my catamorphism function crashes swiftc. This seems to be a result of using curried forms.


Steps to Reproduce:
1. This:
enum E<T> {
	func map<U>(_ : T -> U) -> E<U> { return .C }
	case C
}
protocol FixpointType {
	typealias Recur

	init(_ : Recur)
	var out: Recur { get }
}
func out<Fix: FixpointType>(v: Fix) -> Fix.Recur {
	return v.out
}
func flip<T, U, V>(f: T -> U -> V)(_ x: U)(_ y: T) -> V {
	return f(y)(x)
}
func cata<T, Fix: FixpointType where Fix.Recur == E<Fix>>(f: E<T> -> T)(_ term: Fix) -> T {
	return f(flip(E.map)(cata(f))(out(term)))
}


Expected Results:
should not crash swiftc


Actual Results:
but totally does:
Assertion failed: (!(fd->getType()->is<AnyFunctionType>() && fd->getType()->castTo<AnyFunctionType>()->getResult() ->is<PolymorphicFunctionType>())), function emitGlobalFunctionRef, file /Library/Caches/com.apple.xbs/Sources/swiftlang/swiftlang-700.0.38.1/src/swift/lib/SILGen/SILGenFunction.cpp, line 153.
0  swift                    0x000000010b4e8e0b llvm::sys::PrintStackTrace(__sFILE*) + 43
1  swift                    0x000000010b4e954b SignalHandler(int) + 379
2  libsystem_platform.dylib 0x00007fff88493f1a _sigtramp + 26
3  libsystem_platform.dylib 0x00007faf19823730 _sigtramp + 2436429872
4  libsystem_c.dylib        0x00007fff86f90b53 abort + 129
5  libsystem_c.dylib        0x00007fff86f58c39 basename + 0
6  swift                    0x00000001097505af swift::Lowering::SILGenFunction::emitGlobalFunctionRef(swift::SILLocation, swift::SILDeclRef, swift::Lowering::SILConstantInfo) + 1359
7  swift                    0x0000000109750bc6 swift::Lowering::SILGenFunction::emitFunctionRef(swift::SILLocation, swift::SILDeclRef, swift::Lowering::SILConstantInfo) + 470
8  swift                    0x0000000109737d85 swift::Lowering::SILGenFunction::emitRValueForDecl(swift::SILLocation, swift::ConcreteDeclRef, swift::Type, swift::AccessSemantics, swift::Lowering::SGFContext) + 853
9  swift                    0x000000010973df2b swift::ASTVisitor<(anonymous namespace)::RValueEmitter, swift::Lowering::RValue, void, void, void, void, void, swift::Lowering::SGFContext>::visit(swift::Expr*, swift::Lowering::SGFContext) + 811
10 swift                    0x00000001097477bb (anonymous namespace)::RValueEmitter::visit(swift::Expr*) + 75
…
Stack dump:
0.	Program arguments: /Applications/Xcode-7-beta.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swift -frontend -interpret ./recur.swift -target x86_64-apple-darwin14.3.0 -enable-objc-interop -sdk /Applications/Xcode-7-beta.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk -module-name recur 
1.	While emitting SIL for 'cata' at ./recur.swift:19:1


Regression:
Didn’t happen in Swift 1.2.

Can work around by replacing flip(E.map)(cata(f)) with { E.map($0)(cata(f)) }


Notes:
N/A