Use new asClassPathString method and create FileUtils for classpath

The method asClasspathString is now deprecated. Moreover it's moved
to ClassFileLookup in the case someone was using it in some project
(an alternative classpath also will support it - just in the case).
All its usages existing in Scala sources are changed to
asClassPathString method. The only difference is the name.

Some operations on files or their names are moved from ClassPath to
the newly created FileUtils dedicated to classpath. It will be
possible to reuse them when implementing an alternative classpath
representation. Moreover such allocation-free extension methods like
the one added in this commit will improve the readability.

1 files changed, 46 insertions, 0 deletions

diff --git a/src/compiler/scala/tools/nsc/classpath/FileUtils.scala b/src/compiler/scala/tools/nsc/classpath/FileUtils.scala
new file mode 100644
index 0000000000..0221454c04
--- /dev/null
+++ b/src/compiler/scala/tools/nsc/classpath/FileUtils.scala
@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2014 Contributor. All rights reserved.
+ */
+package scala.tools.nsc.classpath
+
+import java.net.URL
+import scala.reflect.internal.FatalError
+import scala.reflect.io.AbstractFile
+
+/**
+ * Common methods related to files used in the context of classpath
+ */
+object FileUtils {
+  implicit class AbstractFileOps(val file: AbstractFile) extends AnyVal {
+
+    /**
+     * Safe method returning a sequence containing one URL representing this file, when underlying file exists,
+     * and returning given default value in other case
+     */
+    def toURLs(default: => Seq[URL] = Seq.empty): Seq[URL] = if (file.file == null) default else Seq(file.toURL)
+  }
+
+  def stripSourceExtension(fileName: String): String = {
+    if (endsScala(fileName)) stripClassExtension(fileName)
+    else if (endsJava(fileName)) stripJavaExtension(fileName)
+    else throw new FatalError("Unexpected source file ending: " + fileName)
+  }
+
+  def endsClass(fileName: String): Boolean =
+    fileName.length > 6 && fileName.substring(fileName.length - 6) == ".class"
+
+  def endsScalaOrJava(fileName: String): Boolean =
+    endsScala(fileName) || endsJava(fileName)
+
+  def endsJava(fileName: String): Boolean =
+    fileName.length > 5 && fileName.substring(fileName.length - 5) == ".java"
+
+  def endsScala(fileName: String): Boolean =
+    fileName.length > 6 && fileName.substring(fileName.length - 6) == ".scala"
+
+  def stripClassExtension(fileName: String): String =
+    fileName.substring(0, fileName.length - 6) // equivalent of fileName.length - ".class".length
+
+  def stripJavaExtension(fileName: String): String =
+    fileName.substring(0, fileName.length - 5)
+}