Mercurial Hosting > luan
diff src/luan/impl/UnmExpr.java @ 166:4eaee12f6c65
move luan/interp to impl
git-svn-id: https://luan-java.googlecode.com/svn/trunk@167 21e917c8-12df-6dd8-5cb6-c86387c605b9
| author | fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9> |
|---|---|
| date | Sun, 22 Jun 2014 04:17:38 +0000 |
| parents | src/luan/interp/UnmExpr.java@f5af13062b10 |
| children |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/luan/impl/UnmExpr.java Sun Jun 22 04:17:38 2014 +0000 @@ -0,0 +1,29 @@ +package luan.impl; + +import luan.Luan; +import luan.LuanFunction; +import luan.LuanException; +import luan.LuanSource; +import luan.LuanBit; + + +// unary minus +final class UnmExpr extends UnaryOpExpr { + + UnmExpr(LuanSource.Element se,Expr op) { + super(se,op); + } + + @Override public Object eval(LuanStateImpl luan) throws LuanException { + Object o = op.eval(luan); + Number n = Luan.toNumber(o); + if( n != null ) + return -n.doubleValue(); + LuanBit bit = luan.bit(se); + LuanFunction fn = bit.getHandlerFunction("__unm",o); + if( fn != null ) { + return Luan.first(bit.call(fn,"__unm",new Object[]{o})); + } + throw bit.exception("attempt to perform arithmetic on a "+Luan.type(o)+" value"); + } +}