KrancScript.m: Use Piraha to parse .kranc files

Currently we just print the XML structure to standard output.

Tools/CodeGen/KrancScript.m

@@ -18,18 +18,46 @@
     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *)
 
-BeginPackage["KrancScript`", {"Errors`", "Helpers`", "Kranc`"}];
+BeginPackage["KrancScript`", {"Errors`", "Helpers`", "Kranc`", "JLink`"}];
 
 CreateThornFromKrancScript;
 
 Begin["`Private`"];
 
+InstallJava[];
+
+(* The JRE does not share a current directory with the Mathematica
+   kernel, so relative paths have to be converted to absolute paths.
+   It is not possible to change the JRE working directory. *)
+
+absPath[s_String] :=
+  If[StringTake[s,1] === $PathnameSeparator, s, FileNameJoin[{Directory[],s}]];
+
+fullKrancDir = absPath[KrancDirectory];
+
+Print[AddToClassPath[
+ FileNameJoin[{fullKrancDir, "Tools","PirahaPEG","piraha.jar"}]]];
+
 DefFn[
   parseScript[filename_String] :=
   Module[
-    {},
+    {g,m,c,sw,dout,xmlString,xml},
+    g = JavaNew["edu.lsu.cct.piraha.Grammar"];
+    g@compileFile[JavaNew["java.io.File", FileNameJoin[{fullKrancDir, "Auxiliary", "Grammars","kranc2.peg"}]]];
+
+    c = Grammar`readContents[JavaNew["java.io.File", absPath@filename]];
+
+    m = g@matcher["thorn", c];
+
+    If[!m@match[0], ThrowError["Failed to parse input file: ",m@near[]@toString[]]];
 
-    {}]];
+    sw = JavaNew["java.io.StringWriter"];
+    dout = JavaNew["edu.lsu.cct.piraha.DebugOutput", JavaNew["java.io.PrintWriter", sw]];
+    m@dumpMatchesXML[dout];
+    dout@flush[];
+    xmlString = sw@toString[];
+    xml = ImportString[xmlString, "XML"];
+    xml]];
 
 DefFn[
   CreateThornFromKrancScript[filename_String] :=