Mercurial Hosting > luan
view core/src/luan/impl/IndexExpr.java @ 404:d55e873e1f0d
metatables now only apply to tables
author | Franklin Schmidt <fschmidt@gmail.com> |
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date | Wed, 29 Apr 2015 07:04:40 -0600 |
parents | 3dcb0f9bee82 |
children | 3e68917a0dc6 |
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package luan.impl; import luan.Luan; import luan.LuanException; import luan.LuanTable; import luan.LuanFunction; import luan.LuanSource; import luan.modules.StringLuan; import luan.modules.BinaryLuan; import luan.modules.JavaLuan; final class IndexExpr extends BinaryOpExpr { IndexExpr(LuanSource.Element se,Expr op1,Expr op2) { super(se,op1,op2); } @Override public Object eval(LuanStateImpl luan) throws LuanException { return index(luan,op1.eval(luan),op2.eval(luan)); } private Object index(LuanStateImpl luan,Object obj,Object key) throws LuanException { if( obj instanceof LuanTable ) { LuanTable tbl = (LuanTable)obj; Object value = tbl.get(key); if( value != null ) return value; Object h = luan.getHandler("__index",tbl); if( h==null ) return null; if( h instanceof LuanFunction ) { LuanFunction fn = (LuanFunction)h; return Luan.first(luan.bit(se).call(fn,"__index",new Object[]{tbl,key})); } return index(luan,h,key); } if( obj instanceof String ) return StringLuan.__index(luan,(String)obj,key); if( obj instanceof byte[] ) return BinaryLuan.__index(luan,(byte[])obj,key); Object value = JavaLuan.__index(luan,obj,key); if( value != null ) return value; throw luan.bit(op1.se()).exception( "attempt to index '"+op1.se().text()+"' (a " + Luan.type(obj) + " value)" ); } }