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diff core/src/luan/impl/LenExpr.java @ 171:3dcb0f9bee82
add core component
git-svn-id: https://luan-java.googlecode.com/svn/trunk@172 21e917c8-12df-6dd8-5cb6-c86387c605b9
author | fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9> |
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date | Sun, 22 Jun 2014 05:41:22 +0000 |
parents | src/luan/impl/LenExpr.java@4eaee12f6c65 |
children | d55e873e1f0d |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/core/src/luan/impl/LenExpr.java Sun Jun 22 05:41:22 2014 +0000 @@ -0,0 +1,37 @@ +package luan.impl; + +import luan.Luan; +import luan.LuanTable; +import luan.LuanFunction; +import luan.LuanException; +import luan.LuanSource; +import luan.LuanBit; + + +final class LenExpr extends UnaryOpExpr { + + LenExpr(LuanSource.Element se,Expr op) { + super(se,op); + } + + @Override public Object eval(LuanStateImpl luan) throws LuanException { + Object o = op.eval(luan); + if( o instanceof String ) { + String s = (String)o; + return s.length(); + } + if( o instanceof byte[] ) { + byte[] a = (byte[])o; + return a.length; + } + LuanBit bit = luan.bit(se); + LuanFunction fn = bit.getHandlerFunction("__len",o); + if( fn != null ) + return Luan.first(bit.call(fn,"__len",new Object[]{o})); + if( o instanceof LuanTable ) { + LuanTable t = (LuanTable)o; + return t.length(); + } + throw bit.exception( "attempt to get length of a " + Luan.type(o) + " value" ); + } +}