Enable multi-prefixing/suffixing

You can now provide multiple prefix/suffix elements, and all of the
permutations of them will be applied.

For example, providing the elements A & B, will yield the following
permutations
	* A
	* B
	* A B
	* B A

1 files changed, 12 insertions, 9 deletions

diff --git a/src/main/java/bjc/rgens/parser/RGrammarSet.java b/src/main/java/bjc/rgens/parser/RGrammarSet.java
index 975510a..c797b8c 100755
--- a/src/main/java/bjc/rgens/parser/RGrammarSet.java
+++ b/src/main/java/bjc/rgens/parser/RGrammarSet.java
@@ -7,6 +7,7 @@ import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.TreeMap;
 import java.util.Scanner;
 import java.util.Set;
 
@@ -34,7 +35,7 @@ public class RGrammarSet {
 
 		exportedRules = new HashMap<>();
 
-		exportFrom = new HashMap<>();
+		exportFrom = new TreeMap<>();
 		loadedFrom = new HashMap<>();
 	}
 
@@ -256,14 +257,16 @@ public class RGrammarSet {
 				 */
 				Path convPath = cfgParent.resolve(path.toString());
 
-				//if(Files.isDirectory(convPath)) {
-				//	/* @TODO implement subset grammars */
-				//	throw new GrammarException("Sub-grammar sets aren't implemented yet");
-				//} else if (convPath.getFileName().endsWith(".gram")) {
+				if(Files.isDirectory(convPath)) {
+					/* @TODO implement subset grammars */
+					throw new GrammarException("Sub-grammar sets aren't implemented yet");
+				} else if (convPath.getFileName().toString().endsWith(".gram")) {
 					/* Load grammar file. */
 					try {
+
 						BufferedReader fis = Files.newBufferedReader(convPath);
 						RGrammar gram = RGrammarParser.readGrammar(fis);
+
 						fis.close();
 
 						/* Add grammar to the set. */
@@ -278,10 +281,10 @@ public class RGrammarSet {
 						String msg = String.format("Error loading file '%s'", path);
 						throw new GrammarException(msg, gex);
 					}
-				//} else {
-				//	String msg = String.format("Unrecognized file type '%s'", convPath.getFileName());
-				//	throw new GrammarException(msg);
-				//}
+				} else {
+					String msg = String.format("Unrecognized file type '%s'", convPath.getFileName());
+					throw new GrammarException(msg);
+				}
 			}
 		}