added getFunctionProb in the Java and C API

src/runtime/c/pgf/pgf.c

@@ -165,6 +165,17 @@ pgf_function_type(PgfPGF* pgf, PgfCId funname)
 	return absfun->type;
 }
 
+double
+pgf_function_prob(PgfPGF* pgf, PgfCId funname) 
+{
+	PgfAbsFun* absfun =
+		gu_seq_binsearch(pgf->abstract.funs, pgf_absfun_order, PgfAbsFun, funname);
+	if (absfun == NULL)
+		return INFINITY;
+
+	return absfun->ep.prob;
+}
+
 GuString
 pgf_print_name(PgfConcr* concr, PgfCId id)
 {

src/runtime/c/pgf/pgf.h

@@ -66,6 +66,9 @@ pgf_iter_functions_by_cat(PgfPGF* pgf, PgfCId catname,
 PgfType*
 pgf_function_type(PgfPGF* pgf, PgfCId funname);
 
+double
+pgf_function_prob(PgfPGF* pgf, PgfCId funname);
+
 GuString
 pgf_print_name(PgfConcr*, PgfCId id);
 

src/runtime/java/jpgf.c

@@ -178,6 +178,18 @@ Java_org_grammaticalframework_pgf_PGF_getFunctionType(JNIEnv* env, jobject self,
 	return jtype;
 }
 
+JNIEXPORT jdouble JNICALL
+Java_org_grammaticalframework_pgf_PGF_getFunctionProb(JNIEnv* env, jobject self, jstring jid)
+{
+	PgfPGF* pgf = get_ref(env, self);
+	GuPool* tmp_pool = gu_local_pool();
+	PgfCId id = j2gu_string(env, jid, tmp_pool);
+	double prob = pgf_function_prob(pgf, id);
+	gu_pool_free(tmp_pool);
+
+	return prob;
+}
+
 typedef struct {
 	GuMapItor fn;
 	JNIEnv *env;

src/runtime/java/org/grammaticalframework/pgf/PGF.java

@@ -42,6 +42,12 @@ public class PGF {
 	 */
 	public native Type getFunctionType(String fun);
 
+	/** Returns the negative logarithmic probability of the function
+	 * with the given name.
+	 * @param fun The name of the function.
+	 */
+	public native double getFunctionProb(String fun);
+
 	/** Returns an iterable over the set of all expression in
 	 * the given category. The expressions are enumerated in decreasing
 	 * probability order.