added checkExpr in Java

doc/runtime-api.html

@@ -929,7 +929,7 @@ Prelude PGF2> print e'
 AdjCN (PositA red_A) (UseN theatre_N)
 </pre>
 <pre class="java">
-Expr new_e = gr.checkExpr(e,Type.readType("CN")); //// TODO
+Expr new_e = gr.checkExpr(e,Type.readType("CN"));
 System.out.println(e)
 </pre>
 <pre class="csharp">

src/runtime/java/jpgf.c

@@ -1704,3 +1704,43 @@ Java_org_grammaticalframework_pgf_PGF_inferExpr(JNIEnv* env, jobject self, jobje
 
 	return jtyped_expr;
 }
+
+JNIEXPORT jobject JNICALL
+Java_org_grammaticalframework_pgf_PGF_checkExpr(JNIEnv* env, jobject self, jobject jexpr, jobject jtp)
+{
+	GuPool* pool = gu_new_pool();
+	GuPool* tmp_pool = gu_local_pool();
+	GuExn* err = gu_exn(tmp_pool);
+
+	PgfExpr expr =
+		gu_variant_from_ptr((void*) get_ref(env, jexpr));
+	PgfType* tp  =
+		get_ref(env, jtp);
+	pgf_check_expr(get_ref(env, self), &expr, tp, err, pool);
+	if (!gu_ok(err)) {
+		if (gu_exn_caught(err, PgfExn)) {
+			GuString msg = (GuString) gu_exn_caught_data(err);
+			throw_string_exception(env, "org/grammaticalframework/pgf/PGFError", msg);
+		} else if (gu_exn_caught(err, PgfTypeError)) {
+			GuString msg = (GuString) gu_exn_caught_data(err);
+			throw_string_exception(env, "org/grammaticalframework/pgf/TypeError", msg);
+ 		} else {
+			throw_string_exception(env, "org/grammaticalframework/pgf/PGFError", "The type cannot be inferred");
+		}
+		gu_pool_free(tmp_pool);
+		gu_pool_free(pool);
+		return NULL;
+	}
+
+	gu_pool_free(tmp_pool);
+
+	jclass pool_class = (*env)->FindClass(env, "org/grammaticalframework/pgf/Pool");
+	jmethodID pool_constrId = (*env)->GetMethodID(env, pool_class, "<init>", "(J)V");
+	jobject jpool = (*env)->NewObject(env, pool_class, pool_constrId, p2l(pool));
+
+	jclass expr_class  = (*env)->GetObjectClass(env, jexpr);
+	jmethodID expr_constrId = (*env)->GetMethodID(env, expr_class, "<init>", "(Lorg/grammaticalframework/pgf/Pool;Ljava/lang/Object;J)V");
+	jexpr = (*env)->NewObject(env, expr_class, expr_constrId, jpool, NULL, p2l(gu_variant_to_ptr(expr)));
+
+	return jexpr;
+}

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

@@ -67,7 +67,10 @@ public class PGF {
 	/** Takes an expression and returns a refined version
 	 * of the expression together with its type */
 	public native TypedExpr inferExpr(Expr expr) throws TypeError;
-
+	
+	/** Takes an expression and checks it agains a type. The returned expression
+	 * is a possibly refined version of the original. */
+	public native Expr checkExpr(Expr expr, Type ty) throws TypeError;
 
 	public native String graphvizAbstractTree(Expr expr);