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comparison src/luan/interp/LenExpr.java @ 7:bca8fc5d928b

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work on expressions git-svn-id: https://luan-java.googlecode.com/svn/trunk@8 21e917c8-12df-6dd8-5cb6-c86387c605b9
author fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9>
date Tue, 20 Nov 2012 10:06:27 +0000
parents src/luan/interp/LengthExpr.java@7a2cdbc5767f
children b7d7069fee58
comparison
equal deleted inserted replaced
6:a315783c9524 7:bca8fc5d928b
1 package luan.interp;
2
3 import luan.Lua;
4 import luan.LuaNumber;
5 import luan.LuaTable;
6 import luan.LuaException;
7 import luan.LuaState;
8
9
10 final class LenExpr extends UnaryOpExpr {
11
12 LenExpr(Expr op) {
13 super(op);
14 }
15
16 @Override Object eval(LuaState lua) throws LuaException {
17 return new LuaNumber( length(op.eval(lua)) );
18 }
19
20 private static int length(Object obj) throws LuaException {
21 if( obj instanceof String ) {
22 String s = (String)obj;
23 return s.length();
24 }
25 if( obj instanceof LuaTable ) {
26 LuaTable t = (LuaTable)obj;
27 return t.length();
28 }
29 throw new LuaException( "attempt to get length of a " + Lua.type(obj) + " value" );
30 }
31 }