code: public static String ceylonRepoPath(final String groupId, final String artifactId, final String version,
              final String classifier, final String extension) {
          
          StringBuilder path = new StringBuilder(STRING_BUILDER_SIZE);
      
          path.append(formatAsDirectory(groupId)).append(PATH_SEPARATOR);
          path.append(artifactId).append(PATH_SEPARATOR);
          path.append(version).append(PATH_SEPARATOR);
          path.append(ceylonModuleName(groupId, artifactId, version, classifier, extension));
      
          return path.toString();
      }
docs: Determines the relative path of a module atifact within a Ceylon repo.
  
  @param groupId Maven group id
  @param artifactId Maven artifact id
  @param version Version
  @param classifier Sources, javadoc etc.
  @param extension The extension or packaging of the artifact
  @return String The computed path