DRY isLibrary check

Author: mxcl

Sources/Build/describe().swift

@@ -81,7 +81,7 @@ public func describe(prefix: String, _ conf: Configuration, _ modules: [Module],
 
             // this must be set or swiftc compiles single source file
             // modules with a main() for some reason
-            try write("    is-library: ", module.isLibrary)
+            try write("    is-library: ", module.type == .Library)
 
             for o in node.objectPaths {
                 mkdirs.insert(o.parentDirectory)
@@ -92,7 +92,7 @@ public func describe(prefix: String, _ conf: Configuration, _ modules: [Module],
             var args = ["-c", "-emit-module", "-D", "SWIFT_PACKAGE", "-O", "-whole-module-optimization", "-I", prefix] + swiftcArgs
             let productPath = Path.join(prefix, "\(module.c99name).o")
 
-            if module.isLibrary {
+            if module.type == .Library {
                 args += ["-parse-as-library"]
             }
 

Sources/PackageType/Module.swift

@@ -49,10 +49,15 @@ public class SwiftModule: Module {
         super.init(name: name)
     }
 
-    public var isLibrary: Bool {
-        return !sources.relativePaths.contains { path in
+    public enum ModuleType {
+        case Library, Executable
+    }
+
+    public var type: ModuleType {
+        let isLibrary = !sources.relativePaths.contains { path in
             path.basename.lowercaseString == "main.swift"
         }
+        return isLibrary ? .Library : .Executable
     }
 }
 

Sources/Transmute/Package+products.swift

@@ -18,7 +18,7 @@ extension Package {
     ////// first auto-determine executables
 
         for case let module as SwiftModule in modules {
-            if module.sources.relativePaths.contains("main.swift") {
+            if module.type == .Executable {
                 let product = Product(name: module.name, type: .Executable, modules: [module])
                 products.append(product)
             }

Sources/Transmute/fillModuleGraph().swift

@@ -18,7 +18,7 @@ func fillModuleGraph(packages: [Package], modulesForPackage: (Package) -> [Modul
                 switch $0 {
                 case is TestModule:
                     return false
-                case let module as SwiftModule where module.isLibrary:
+                case let module as SwiftModule where module.type == .Library:
                     return true
                 case is CModule:
                     return true