Merge pull request #21 from compgen-io/bed-combine-2

Bed combine 2

src/java/io/compgen/ngsutils/bed/BedStrandFilter.java

@@ -0,0 +1,43 @@
+package io.compgen.ngsutils.bed;
+
+import java.util.Iterator;
+
+import io.compgen.ngsutils.bam.Strand;
+
+public class BedStrandFilter implements Iterator<BedRecord>{
+	protected final Iterator<BedRecord> it;
+	protected final Strand strand;
+
+	protected BedRecord cur = null;
+
+    public BedStrandFilter(Iterator<BedRecord> it, Strand strand) {
+    	this.it = it;
+    	this.strand = strand;
+    }
+	@Override
+	public boolean hasNext() {
+		if (cur == null && it.hasNext()) {
+			populate();
+		}
+		return cur != null;
+	}
+	@Override
+	public BedRecord next() {
+		BedRecord ret = cur;
+		cur = null;
+		populate();
+
+		return ret;
+	}
+
+	private void populate() {
+		while (it.hasNext()) {
+			BedRecord tmp = it.next();
+			if (strand.matches(tmp.coord.strand)) {
+				cur = tmp;
+				return;
+			}
+		}
+	}
+}
+