LuaArray.java

package se.krka.kahlua.vm;

import se.krka.kahlua.stdlib.BaseLib;

public class LuaArray implements LuaTable {

	private LuaTable metatable;
	
	private Object[] data;
	private int len;

    private boolean recalculateLen;

	public LuaArray() {
		data = new Object[16];
		len = 0;
	}
	
	public int len() {
        if (recalculateLen) {
            int index = this.len - 1;
            Object[] data = this.data;
            while (index >= 0) {
                if (data[index] != null) {
                    break;
                }
                index--;
            }
            this.len = index + 1;
            recalculateLen = false;
        }
		return len;
	}

    public Object rawget(int index) {
        if (index < 1 || index > len) {
            return null;
        }
        return data[(index - 1)];
    }

    public void rawset(int index, Object value) {
        if (index <= 0) {
            BaseLib.fail("Index out of range: " + index);
        }
        if (index >= len) {
	        if (value == null) {
	        	if (index == len) {
	                data[index - 1] = value;
	                recalculateLen = true;
	        	}
	        	return;
	        }
            if (data.length < index) {
                int newMaxLen = 2 * index;
                int newCap = newMaxLen - 1;
                Object[] newData = new Object[newCap];
                System.arraycopy(data, 0, newData, 0, len);
                data = newData;
            }
            len = index;
        }
        data[(index - 1)] = value;
    }

    private int getKeyIndex(Object key) {
        if (key instanceof Double) {
            Double d = (Double) key;
            return d.intValue();
        }
        return -1;
    }

    public Object rawget(Object key) {
        LuaTableImpl.checkKey(key);
        int index = getKeyIndex(key);
        return rawget(index);
    }

    public void rawset(Object key, Object value) {
        LuaTableImpl.checkKey(key);
        int index = getKeyIndex(key);
        if (index == -1) {
            BaseLib.fail("Invalid table key: " + key);
        }
        rawset(index, value);
    }

    public Object next(Object key) {
		int index;
		if (key == null) {
			index = 0;
		} else {
            index = getKeyIndex(key);
            if (index <= 0 || index > len) {
                BaseLib.fail("invalid key to 'next'");
                return null;
            }
		}
		while (index < len) {
			if (data[index] != null) {
				return LuaState.toDouble(index + 1);
			}
			index++;
		}
		return null;
	}

    public LuaTable getMetatable() {
		return metatable;
	}

	public void setMetatable(LuaTable metatable) {
		this.metatable = metatable;
	}

	public void updateWeakSettings(boolean weakKeys, boolean weakValues) {
		BaseLib.fail("Can't set weakness on arrays");
	}
}