REXPGenericVector.java

package org.rosuda.REngine;
import java.util.Vector;
import java.util.HashMap;

/** REXPGenericVector represents a generic vector in R. Its elements can be typically of any {@link REXP} type. */
public class REXPGenericVector extends REXPVector {
	/** payload */
	private RList payload;
	
	/** creates a new generic vector from a list. If the list is named, the <code>"names"</code> attribute is created automatically from it.
	 *  @param list list to create the vector from */
	public REXPGenericVector(RList list) {
		super();
		payload=(list==null)?new RList():list;
		// automatically generate 'names' attribute
		if (payload.isNamed())
			attr = new REXPList(
				new RList(new REXP[] { new REXPString(payload.keys()) },
						  new String[] { "names" }));
	}
	
	/** creates a new generic vector from a list. Note that the names in the list are ignored as they are expected to be defined by the attributes parameter.
	 *  @param list list to create the vector from (names are ignored - use {@link #REXPGenericVector(RList)} or the <code>"names"</code> attribute for named lists
	 *  @param attr attributes */
	public REXPGenericVector(RList list, REXPList attr) {
		super(attr);
		payload=(list==null)?new RList():list;
	}

	/* generic vectors are converted either to a <code>Map</code> (if it is a named vector and there are no duplicate names) or a <code>Vector</code>. The contained elements are converted using <code>asNativeJavaObject</code> recursively. */
	public Object asNativeJavaObject() throws REXPMismatchException {
		// we need to convert the inside as well
		int n = payload.size();

		// named list -> map but only if
		//  a) all names are present
		//  b) there are no duplicates in the names
		if (payload.isNamed()) {
			String[] names = payload.keys();
			if (names.length == n) {
				HashMap map = new HashMap();
				boolean valid = true;
				for (int i = 0; i < n; i++) {
					if (map.containsKey(names[i])) {
						valid = false;
						break;
					}
					Object value = payload.elementAt(i);
					if (value != null)
						value = ((REXP) value).asNativeJavaObject();
					map.put(names[i], value);
				}
				if (valid)
					return map;
			}
		}

		// otherwise drop names and use just a vector
		Vector v = new Vector();
		for (int i = 0; i < n; i++) {
			Object value = payload.elementAt(i);
			if (value != null)
				value = ((REXP) value).asNativeJavaObject();
			v.addElement(value);
		}

		return v;
	}
	
	public int length() { return payload.size(); }

	public boolean isList() { return true; }

	public boolean isRecursive() { return true; }

	public RList asList() { return payload; }
	
	public String toString() {
		return super.toString()+(asList().isNamed()?"named":"");
	}

	public String toDebugString() {
		StringBuffer sb = new StringBuffer(super.toDebugString()+"{");
		int i = 0;
		while (i < payload.size() && i < maxDebugItems) {
			if (i>0) sb.append(",\n");
			sb.append(payload.at(i).toDebugString());
			i++;
		}
		if (i < payload.size()) sb.append(",..");
		return sb.toString()+"}";
	}
}