diff --git a/SwiftShell/Command.swift b/SwiftShell/Command.swift
index fc3d1a9..d91f15e 100644
--- a/SwiftShell/Command.swift
+++ b/SwiftShell/Command.swift
@@ -85,5 +85,5 @@ public func $ (shellcommand: String) -> String {
 
 /** Turn a sequence into valid parameters for a shell command, properly quoted */
 public func parameters <S : SequenceType> (sequence: S) -> String {
-	return " " + " ".join( sequence.map { "\"\($0)\"" } )
+	return " " + ( sequence.map { "\"\($0)\"" } ).joinWithSeparator(" ")
 }
diff --git a/SwiftShell/FileHandle.swift b/SwiftShell/FileHandle.swift
index 7ad3eab..fe5f757 100644
--- a/SwiftShell/FileHandle.swift
+++ b/SwiftShell/FileHandle.swift
@@ -71,16 +71,25 @@ extension FileHandle: WriteableStreamType {
 	exit(EXIT_FAILURE)
 }
 
+/** Run a function which takes a NSErrorPointer. If an NSError occurs, throw it, otherwise return result. */
+func makeThrowable <T> (nserrorfunc: (NSErrorPointer) -> T) throws -> T {
+	var maybeerror: NSError?
+	let result = nserrorfunc(&maybeerror)
+	if let actualerror = maybeerror {
+		throw actualerror
+	}
+	return result
+}
+
 /** Open a file for reading, and exit if an error occurs. */
 public func open (path: String) -> ReadableStreamType {
 
 	let url = toURLOrError(path)
 	do {
-		let filehandle = try FileHandle(forReadingFromURL: url)
-		return filehandle
+		return try FileHandle(forReadingFromURL: url)
 	} catch {
 		do {
-			try url.checkResourceIsReachable()
+			try makeThrowable(url.checkResourceIsReachableAndReturnError)
 		} catch {
 			printErrorAndExit(error)
 		}
@@ -107,7 +116,7 @@ public func open (forWriting path: String, overwrite: Bool = false) -> Writeable
 		return filehandle
 	} catch {
 		do {
-			try url.checkResourceIsReachable()
+			try makeThrowable(url.checkResourceIsReachableAndReturnError)
 		} catch {
 			printErrorAndExit(error)
 		}
diff --git a/SwiftShell/Pipes.swift b/SwiftShell/Pipes.swift
index 659dc07..6920377 100644
--- a/SwiftShell/Pipes.swift
+++ b/SwiftShell/Pipes.swift
@@ -22,9 +22,9 @@ public func |> <T,U> (lhs: T, rhs: T -> U) -> U {
 public func filter <S : SequenceType>
 	(includeElement: (S.Generator.Element) -> Bool)
 	(source: S)
-	-> LazySequence<FilterSequence<S>> {
+	-> LazyFilterSequence<S> {
 
-		return lazy(source).filter(includeElement)
+		return source.lazy.filter(includeElement)
 }
 
 /**
@@ -45,9 +45,9 @@ public func sorted <S : SequenceType>
 public func map <S: SequenceType, T>
 	(transform: (S.Generator.Element) -> T)
 	(source: S)
-	-> LazySequence<MapSequence<S, T>> {
+	-> LazyMapSequence<S,T> {
 
-		return lazy(source).map(transform)
+		return source.lazy.map(transform)
 }
 
 /**
@@ -71,9 +71,9 @@ public func split (delimiter delimiter: String = "\n")(text: String) -> [String]
 public func join <C : RangeReplaceableCollectionType, S : SequenceType where S.Generator.Element == C>
 	(separator: C)
 	(elements: S)
-	-> C {
+	-> JoinSequence<S> {
 
-		return join(separator, elements)
+		return elements.joinWithSeparator(separator)
 }
 
 /** Turn a sequence into an array. For use after the |> operator. */
@@ -85,7 +85,7 @@ public func toArray <S : SequenceType> (sequence: S) -> [S.Generator.Element] {
 public func drop <S : SequenceType, T : Equatable where S.Generator.Element == T>
 	(tobedropped: [T])
 	(sequence: S)
-	-> LazySequence<FilterSequence<S>> {
+	-> LazyFilterSequence<S> {
 		
 		return sequence |> filter { !tobedropped.contains($0) }
 }
diff --git a/SwiftShellTests/Scripts/runtests.bash b/SwiftShellTests/Scripts/runtests.bash
index 70cbcf9..3ae3dca 100755
--- a/SwiftShellTests/Scripts/runtests.bash
+++ b/SwiftShellTests/Scripts/runtests.bash
@@ -19,7 +19,7 @@ export DYLD_FRAMEWORK_PATH=$PROJECT_ROOT/build/Release/
 
 # Be aware the “assert” command does not check standard error output or exit code.
 
-assert "./print_arguments.swift 1 2" "[./print_arguments.swift, 1, 2]"
+assert "./print_arguments.swift 1 2" "[\"./print_arguments.swift\", \"1\", \"2\"]"
 assert_raises "./exitswhenopeningnon-existentfile.swift" 1
 assert "cat onetwothree.txt | ./print_linenumbers.swift" "line 1: one\nline 2: two\nline 3: three"
 assert "./stream_out.swift" "       3"