From 6d588bfe29fbc33cde914f79752c3d0a0f80c9bc Mon Sep 17 00:00:00 2001
From: Kare Morstol <kare@nottoobadsoftware.com>
Date: Thu, 23 Oct 2014 01:41:53 +0200
Subject: [PATCH] Add "parameters" function for turning a sequence into valid
 parameters for a shell command, properly quoted.

---
 SwiftShell/Command.swift            |  4 ++++
 SwiftShellTests/Command_Tests.swift | 16 ++++++++++++++++
 2 files changed, 20 insertions(+)

diff --git a/SwiftShell/Command.swift b/SwiftShell/Command.swift
index a13e35d..ed0190a 100644
--- a/SwiftShell/Command.swift
+++ b/SwiftShell/Command.swift
@@ -86,3 +86,7 @@ public func $ (shellcommand: String) -> String {
 	return output.fileHandleForReading.read().trim()
 }
 
+/** Turn a sequence into valid parameters for a shell command, properly quoted */
+public func parameters <S : SequenceType>(sequence: S) -> String {
+	return sequence |> map {"\"\(toString($0))\""} |> join(" ")
+}
diff --git a/SwiftShellTests/Command_Tests.swift b/SwiftShellTests/Command_Tests.swift
index 3cbe914..1ad9831 100644
--- a/SwiftShellTests/Command_Tests.swift
+++ b/SwiftShellTests/Command_Tests.swift
@@ -32,4 +32,20 @@ class Command_Tests: XCTestCase {
 		let result = stream("line 1\nline 2\nline 3") |> SwiftShell.run("grep " + $("echo 2"))
 		XCTAssertEqual( result.read(), "line 2\n")
 	}
+	
+	func testParametersFromSequenceOfStrings () {
+		XCTAssertEqual( parameters(["one", "two", "three"]), "\"one\" \"two\" \"three\"" )
+	}
+	
+	func testParametersFromSequenceOfStreams () {
+		var (writable, readable) = streams()
+		
+		let result = SequenceOf([stream("one"), stream("two"), stream("three")].generate()) |> parameters
+		
+		XCTAssertEqual( result, "\"one\" \"two\" \"three\"" )
+	}
+	
+	func testParametersFromSequenceOfNumbers () {
+		XCTAssertEqual( parameters([1, 2, 3]), "\"1\" \"2\" \"3\"" )
+	}
 }