--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/luan/impl/LuanImpl.java	Fri Aug 26 14:36:40 2016 -0600
@@ -0,0 +1,250 @@
+package luan.impl;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.ArrayList;
+import luan.Luan;
+import luan.LuanState;
+import luan.LuanTable;
+import luan.LuanFunction;
+import luan.LuanException;
+import luan.modules.JavaLuan;
+
+
+public final class LuanImpl {
+	private LuanImpl() {}  // never
+
+	public static int len(LuanState luan,Object o) throws LuanException {
+		if( o instanceof String ) {
+			String s = (String)o;
+			return s.length();
+		}
+		if( o instanceof byte[] ) {
+			byte[] a = (byte[])o;
+			return a.length;
+		}
+		if( o instanceof LuanTable ) {
+			LuanTable t = (LuanTable)o;
+			return t.length(luan);
+		}
+		throw new LuanException( "attempt to get length of a " + Luan.type(o) + " value" );
+	}
+
+	public static Object unm(LuanState luan,Object o) throws LuanException {
+		if( o instanceof Number )
+			return -((Number)o).doubleValue();
+		if( o instanceof LuanTable ) {
+			LuanFunction fn = Luan.getHandlerFunction("__unm",(LuanTable)o);
+			if( fn != null ) {
+				return Luan.first(fn.call(luan,new Object[]{o}));
+			}
+		}
+		throw new LuanException("attempt to perform arithmetic on a "+Luan.type(o)+" value");
+	}
+
+	private static Object arithmetic(LuanState luan,String op,Object o1,Object o2) throws LuanException {
+		LuanFunction fn = Luan.getBinHandler(op,o1,o2);
+		if( fn != null )
+			return Luan.first(fn.call(luan,new Object[]{o1,o2}));
+		String type = !(o1 instanceof Number) ? Luan.type(o1) : Luan.type(o2);
+		throw new LuanException("attempt to perform arithmetic on a "+type+" value");
+	}
+
+	public static Object pow(LuanState luan,Object o1,Object o2) throws LuanException {
+		if( o1 instanceof Number && o2 instanceof Number )
+			return Math.pow( ((Number)o1).doubleValue(), ((Number)o2).doubleValue() );
+		return arithmetic(luan,"__pow",o1,o2);
+	}
+
+	public static Object mul(LuanState luan,Object o1,Object o2) throws LuanException {
+		if( o1 instanceof Number && o2 instanceof Number )
+			return ((Number)o1).doubleValue() * ((Number)o2).doubleValue();
+		return arithmetic(luan,"__mul",o1,o2);
+	}
+
+	public static Object div(LuanState luan,Object o1,Object o2) throws LuanException {
+		if( o1 instanceof Number && o2 instanceof Number )
+			return ((Number)o1).doubleValue() / ((Number)o2).doubleValue();
+		return arithmetic(luan,"__div",o1,o2);
+	}
+
+	public static Object mod(LuanState luan,Object o1,Object o2) throws LuanException {
+		if( o1 instanceof Number && o2 instanceof Number ) {
+			double d1 = ((Number)o1).doubleValue();
+			double d2 = ((Number)o2).doubleValue();
+			return d1 - Math.floor(d1/d2)*d2;
+		}
+		return arithmetic(luan,"__mod",o1,o2);
+	}
+
+	public static Object add(LuanState luan,Object o1,Object o2) throws LuanException {
+		if( o1 instanceof Number && o2 instanceof Number )
+			return ((Number)o1).doubleValue() + ((Number)o2).doubleValue();
+		return arithmetic(luan,"__add",o1,o2);
+	}
+
+	public static Object sub(LuanState luan,Object o1,Object o2) throws LuanException {
+		if( o1 instanceof Number && o2 instanceof Number )
+			return ((Number)o1).doubleValue() - ((Number)o2).doubleValue();
+		return arithmetic(luan,"__sub",o1,o2);
+	}
+
+	public static Object concat(LuanState luan,Object o1,Object o2) throws LuanException {
+		LuanFunction fn = Luan.getBinHandler("__concat",o1,o2);
+		if( fn != null )
+			return Luan.first(fn.call(luan,new Object[]{o1,o2}));
+		String s1 = luan.toString(o1);
+		String s2 = luan.toString(o2);
+		return s1 + s2;
+	}
+
+	public static boolean eq(LuanState luan,Object o1,Object o2) throws LuanException {
+		if( o1 == o2 || o1 != null && o1.equals(o2) )
+			return true;
+		if( o1 instanceof Number && o2 instanceof Number ) {
+			Number n1 = (Number)o1;
+			Number n2 = (Number)o2;
+			return n1.doubleValue() == n2.doubleValue();
+		}
+		if( o1 instanceof byte[] && o2 instanceof byte[] ) {
+			byte[] b1 = (byte[])o1;
+			byte[] b2 = (byte[])o2;
+			return Arrays.equals(b1,b2);
+		}
+		if( !(o1 instanceof LuanTable && o2 instanceof LuanTable) )
+			return false;
+		LuanTable t1 = (LuanTable)o1;
+		LuanTable t2 = (LuanTable)o2;
+		LuanTable mt1 = t1.getMetatable();
+		LuanTable mt2 = t2.getMetatable();
+		if( mt1==null || mt2==null )
+			return false;
+		Object f = mt1.rawGet("__eq");
+		if( f == null || !f.equals(mt2.rawGet("__eq")) )
+			return false;
+		LuanFunction fn = Luan.checkFunction(f);
+		return Luan.checkBoolean( Luan.first(fn.call(luan,new Object[]{o1,o2})) );
+	}
+
+	public static boolean le(LuanState luan,Object o1,Object o2) throws LuanException {
+		if( o1 instanceof Number && o2 instanceof Number ) {
+			Number n1 = (Number)o1;
+			Number n2 = (Number)o2;
+			return n1.doubleValue() <= n2.doubleValue();
+		}
+		if( o1 instanceof String && o2 instanceof String ) {
+			String s1 = (String)o1;
+			String s2 = (String)o2;
+			return s1.compareTo(s2) <= 0;
+		}
+		LuanFunction fn = Luan.getBinHandler("__le",o1,o2);
+		if( fn != null )
+			return Luan.checkBoolean( Luan.first(fn.call(luan,new Object[]{o1,o2})) );
+		fn = Luan.getBinHandler("__lt",o1,o2);
+		if( fn != null )
+			return !Luan.checkBoolean( Luan.first(fn.call(luan,new Object[]{o2,o1})) );
+		throw new LuanException( "attempt to compare " + Luan.type(o1) + " with " + Luan.type(o2) );
+	}
+
+	public static boolean lt(LuanState luan,Object o1,Object o2) throws LuanException {
+		return Luan.isLessThan(luan,o1,o2);
+	}
+
+	public static boolean cnd(Object o) throws LuanException {
+		return !(o == null || Boolean.FALSE.equals(o));
+	}
+
+	public static void nop(Object o) {}
+
+	public static void put(LuanState luan,Object t,Object key,Object value) throws LuanException {
+		if( t instanceof LuanTable ) {
+			LuanTable tbl = (LuanTable)t;
+			tbl.put(luan,key,value);
+			return;
+		}
+		if( t != null && luan.java.ok )
+			JavaLuan.__new_index(luan,t,key,value);
+		else
+			throw new LuanException( "attempt to index a " + Luan.type(t) + " value" );
+	}
+
+	public static Object pick(Object o,int i) {
+		if( i < 1 )
+			throw new RuntimeException();
+		if( !(o instanceof Object[]) )
+			return null;
+		Object[] a = (Object[])o;
+		return i<a.length ? a[i] : null;
+	}
+
+	public static Object[] varArgs(Object[] a,int i) {
+		if( i >= a.length )
+			return LuanFunction.NOTHING;
+		Object[] rtn = new Object[a.length - i];
+		System.arraycopy(a,i,rtn,0,rtn.length);
+		return rtn;
+	}
+
+	public static Object[] concatArgs(Object o1,Object o2) {
+		if( o1 instanceof Object[] ) {
+			Object[] a1 = (Object[])o1;
+			if( o2 instanceof Object[] ) {
+				Object[] a2 = (Object[])o2;
+				Object[] rtn = new Object[a1.length+a2.length];
+				System.arraycopy(a1,0,rtn,0,a1.length);
+				System.arraycopy(a2,0,rtn,a1.length,a2.length);
+				return rtn;
+			} else {
+				Object[] rtn = new Object[a1.length+1];
+				System.arraycopy(a1,0,rtn,0,a1.length);
+				rtn[a1.length] = o2;
+				return rtn;
+			}
+		} else {
+			if( o2 instanceof Object[] ) {
+				Object[] a2 = (Object[])o2;
+				Object[] rtn = new Object[1+a2.length];
+				rtn[0] = o1;
+				System.arraycopy(a2,0,rtn,1,a2.length);
+				return rtn;
+			} else {
+				Object[] rtn = new Object[2];
+				rtn[0] = o1;
+				rtn[2] = o2;
+				return rtn;
+			}
+		}
+	}
+
+	public static LuanTable table(Object[] a) {
+		LuanTable table = new LuanTable();
+		int i = 0;
+		for( Object fld : a ) {
+			if( fld instanceof TableField ) {
+				TableField tblFld = (TableField)fld;
+				Object key = tblFld.key;
+				Object value = tblFld.value;
+				if( key != null && value != null )
+					table.rawPut(key,value);
+			} else {
+				i++;
+				if( fld != null )
+					table.rawPut(i,fld);
+			}
+		}
+		return table;
+	}
+
+	public static Object first(Object[] a) {
+		return a.length==0 ? null : a[0];
+	}
+
+	public static String strconcat(String... a) {
+		StringBuilder sb = new StringBuilder();
+		for( String s : a ) {
+			sb.append(s);
+		}
+		return sb.toString();
+	}
+
+}