Mercurial Hosting > luan
view src/luan/interp/IndexExpr.java @ 35:e51906de0f11
implement metatables
git-svn-id: https://luan-java.googlecode.com/svn/trunk@36 21e917c8-12df-6dd8-5cb6-c86387c605b9
author | fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9> |
---|---|
date | Tue, 18 Dec 2012 07:05:58 +0000 |
parents | |
children | 2a35154aec14 |
line wrap: on
line source
package luan.interp; import luan.Lua; import luan.LuaException; import luan.LuaTable; import luan.LuaFunction; final class IndexExpr extends BinaryOpExpr { IndexExpr(Expr op1,Expr op2) { super(op1,op2); } @Override public Object eval(LuaStateImpl lua) throws LuaException { return index(lua,op1.eval(lua),op2.eval(lua)); } private static Object index(LuaStateImpl lua,Object t,Object key) throws LuaException { Object h; if( t instanceof LuaTable ) { LuaTable tbl = (LuaTable)t; Object value = tbl.get(key); if( value != null ) return value; h = Utils.getHandlerObject("__index",t); if( h==null ) return null; } else { h = Utils.getHandlerObject("__index",t); if( h==null ) throw new LuaException( "attempt to index a " + Lua.type(t) + " value" ); } if( h instanceof LuaFunction ) { LuaFunction fn = (LuaFunction)h; return Utils.first(fn.call(lua,t,key)); } return index(lua,h,key); } }