Mercurial Hosting > luan
diff src/luan/Lua.java @ 1:2df768b926aa
start Luan
git-svn-id: https://luan-java.googlecode.com/svn/trunk@2 21e917c8-12df-6dd8-5cb6-c86387c605b9
author | fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9> |
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date | Tue, 13 Nov 2012 05:54:32 +0000 |
parents | |
children | 4da26b11d12a |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/luan/Lua.java Tue Nov 13 05:54:32 2012 +0000 @@ -0,0 +1,56 @@ +package luan; + + +public class Lua { + + public static String toString(Object obj) { + if( obj == null ) + return "nil"; + return obj.toString(); + } + + public static String type(Object obj) { + if( obj == null ) + return "nil"; + if( obj instanceof String ) + return "string"; + if( obj instanceof Boolean ) + return "boolean"; + if( obj instanceof LuaNumber ) + return "number"; + return "userdata"; + } + + public static int length(Object obj) throws LuaException { + if( obj instanceof String ) { + String s = (String)obj; + return s.length(); + } + if( obj instanceof LuaTable ) { + LuaTable t = (LuaTable)obj; + return t.length(); + } + throw new LuaException( "attempt to get length of a " + type(obj) + " value" ); + } + + static LuaNumber toNumber(Object obj) throws LuaException { + if( obj instanceof LuaNumber ) + return (LuaNumber)obj; + if( obj instanceof String ) { + String s = (String)obj; + try { + return new LuaNumber( Double.parseDouble(s) ); + } catch(NumberFormatException e) {} + } + throw new LuaException( "attempt to perform arithmetic on a " + type(obj) + " value" ); + } + + static LuaNumber add(Object n1,Object n2) throws LuaException { + return new LuaNumber( toNumber(n1).n + toNumber(n2).n ); + } + + static LuaNumber sub(Object n1,Object n2) throws LuaException { + return new LuaNumber( toNumber(n1).n - toNumber(n2).n ); + } + +}