Mercurial Hosting > luan
view src/luan/LuaState.java @ 40:e3624b7cd603
implement stack trace
git-svn-id: https://luan-java.googlecode.com/svn/trunk@41 21e917c8-12df-6dd8-5cb6-c86387c605b9
author | fschmidt@gmail.com <fschmidt@gmail.com@21e917c8-12df-6dd8-5cb6-c86387c605b9> |
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date | Fri, 21 Dec 2012 10:45:54 +0000 |
parents | 8a57ebfdfd78 |
children | 786699c78837 |
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package luan; import java.util.List; import java.util.ArrayList; public abstract class LuaState { private final LuaTable global = new LuaTable(); private final List<MetatableGetter> mtGetters = new ArrayList<MetatableGetter>(); final List<StackTraceElement> stackTrace = new ArrayList<StackTraceElement>(); public final LuaTable global() { return global; } public final LuaTable getMetatable(Object obj) { if( obj instanceof LuaTable ) { LuaTable table = (LuaTable)obj; return table.getMetatable(); } for( MetatableGetter mg : mtGetters ) { LuaTable table = mg.getMetatable(obj); if( table != null ) return table; } return null; } public final void addMetatableGetter(MetatableGetter mg) { mtGetters.add(mg); } public Object[] call(LuaFunction fn,LuaElement calledFrom,String fnName,Object... args) throws LuaException { stackTrace.add( new StackTraceElement(calledFrom,fnName) ); try { return fn.call(this,args); } finally { stackTrace.remove(stackTrace.size()-1); } } public final String checkString(LuaElement el,Object obj) throws LuaException { String s = Lua.asString(obj); if( s == null ) throw new LuaException( this, el, "attempt to use a " + Lua.type(obj) + " as a string" ); return s; } public final LuaNumber checkNumber(LuaElement el,Object obj) throws LuaException { LuaNumber n = Lua.toNumber(obj); if( n == null ) throw new LuaException( this, el, "attempt to perform arithmetic on a " + Lua.type(obj) + " value" ); return n; } public final LuaFunction checkFunction(LuaElement el,Object obj) throws LuaException { if( obj instanceof LuaFunction ) return (LuaFunction)obj; throw new LuaException( this, el, "attempt to call a " + Lua.type(obj) + " value" ); } public final String toString(LuaElement el,Object obj) throws LuaException { LuaFunction fn = getHandlerFunction(el,"__tostring",obj); if( fn != null ) return checkString( el, Lua.first( call(fn,el,"__tostring",obj) ) ); if( obj == null ) return "nil"; return obj.toString(); } public final LuaFunction getHandlerFunction(LuaElement el,String op,Object obj) throws LuaException { Object f = getHandler(op,obj); if( f == null ) return null; return checkFunction(el,f); } public final Object getHandler(String op,Object obj) { LuaTable t = getMetatable(obj); return t==null ? null : t.get(op); } }