From 4e328d1f3311c830300487e3f6afd34069ff8923 Mon Sep 17 00:00:00 2001
From: "kr.angelov" <kr.angelov@gmail.com>
Date: Fri, 6 Sep 2013 07:21:38 +0000
Subject: [PATCH] added exhaustive generation in the Java binding

---
 src/runtime/java/Test.java                    |  8 +++++
 src/runtime/java/jpgf.c                       | 22 ++++++++++++++
 .../grammaticalframework/pgf/Generator.java   | 29 +++++++++++++++++++
 .../org/grammaticalframework/pgf/PGF.java     |  4 ++-
 4 files changed, 62 insertions(+), 1 deletion(-)
 create mode 100644 src/runtime/java/org/grammaticalframework/pgf/Generator.java

diff --git a/src/runtime/java/Test.java b/src/runtime/java/Test.java
index 303eaf35f..77de413b3 100644
--- a/src/runtime/java/Test.java
+++ b/src/runtime/java/Test.java
@@ -19,6 +19,14 @@ public class Test {
 		for (Map.Entry<String,Concr> entry : gr.getLanguages().entrySet()) {
 			System.out.println(entry.getKey()+" "+entry.getValue()+" "+entry.getValue().getName());
 		}
+		
+		int count = 10;
+		for (ExprProb ep : gr.generateAll("Phrase")) {
+			System.out.println(ep.getExpr());
+			
+			if (count-- <= 0)
+				break;
+		}
 
 		Concr eng = gr.getLanguages().get("PhrasebookEng");
 		Concr ger = gr.getLanguages().get("PhrasebookGer");
diff --git a/src/runtime/java/jpgf.c b/src/runtime/java/jpgf.c
index 17ae453cb..a0290aeae 100644
--- a/src/runtime/java/jpgf.c
+++ b/src/runtime/java/jpgf.c
@@ -395,3 +395,25 @@ Java_org_grammaticalframework_pgf_Expr_showExpr(JNIEnv* env, jclass clazz, jlong
 	gu_pool_free(tmp_pool);
 	return jstr;
 }
+
+JNIEXPORT jobject JNICALL
+Java_org_grammaticalframework_pgf_Generator_generateAll(JNIEnv* env, jclass clazz, jobject jpgf, jstring jstartCat)
+{
+	GuPool* pool = gu_new_pool();
+
+    GuString startCat = j2gu_string(env, jstartCat, pool);
+
+	GuEnum* res =
+		pgf_generate_all(get_ref(env, jpgf), startCat, pool);
+	if (res == NULL) {
+		throw_string_exception(env, "org/grammaticalframework/pgf/PGFError", "The generation failed");
+		gu_pool_free(pool);
+		return NULL;
+	}
+
+	jclass expiter_class = (*env)->FindClass(env, "org/grammaticalframework/pgf/ExprIterator");
+	jmethodID constrId = (*env)->GetMethodID(env, expiter_class, "<init>", "(Lorg/grammaticalframework/pgf/PGF;JJJ)V");
+	jobject jexpiter = (*env)->NewObject(env, expiter_class, constrId, jpgf, p2l(pool), p2l(pool), p2l(res));
+
+	return jexpiter;
+}
diff --git a/src/runtime/java/org/grammaticalframework/pgf/Generator.java b/src/runtime/java/org/grammaticalframework/pgf/Generator.java
new file mode 100644
index 000000000..c9ffde10b
--- /dev/null
+++ b/src/runtime/java/org/grammaticalframework/pgf/Generator.java
@@ -0,0 +1,29 @@
+package org.grammaticalframework.pgf;
+
+import java.util.Iterator;
+
+class Generator implements Iterable<ExprProb> {
+	private PGF gr;
+	private String startCat;
+	private ExprIterator iter;
+
+	public Generator(PGF gr, String startCat) {
+		this.gr       = gr;
+		this.startCat = startCat;
+		this.iter     = generateAll(gr, startCat);
+	}
+
+	public Iterator<ExprProb> iterator() {
+		if (iter == null) {
+			// If someone has asked for a second iterator over
+			// the same parse results then we have to parse again.
+			return generateAll(gr, startCat);
+		} else {
+			ExprIterator tmp_iter = iter;
+			iter = null;
+			return tmp_iter;
+		}
+	}
+
+	static native ExprIterator generateAll(PGF gr, String startCat);
+}
diff --git a/src/runtime/java/org/grammaticalframework/pgf/PGF.java b/src/runtime/java/org/grammaticalframework/pgf/PGF.java
index 02e5d0c50..c08462b80 100644
--- a/src/runtime/java/org/grammaticalframework/pgf/PGF.java
+++ b/src/runtime/java/org/grammaticalframework/pgf/PGF.java
@@ -22,7 +22,9 @@ public class PGF {
 	
 	public native Type getFunctionType(String fun);
 
-	public native Iterator<ExprProb> generate(Type type);
+	public Iterable<ExprProb> generateAll(String startCat) {
+		return new Generator(this, startCat);
+	}
 
 	public native Expr compute(Expr expr);