Feat: Zero-indexed tables

src/MoonSharp.Interpreter/CoreLib/TableIteratorsModule.cs

@@ -23,7 +23,7 @@ public static DynValue ipairs(ScriptExecutionContext executionContext, CallbackA
 
 			DynValue meta = executionContext.GetMetamethodTailCall(table, "__ipairs", args.GetArray());
 
-			return meta.IsNotNil() ? meta : DynValue.NewTuple(DynValue.NewCallback(__next_i), table, DynValue.NewNumber(0));
+			return meta.IsNotNil() ? meta : DynValue.NewTuple(DynValue.NewCallback(__next_i), table, DynValue.NewNumber(executionContext.OwnerScript.Options.IndexTablesFrom == 0 ? -1 : 0));
 		}
 
 		// pairs (t)
@@ -64,8 +64,8 @@ public static DynValue next(ScriptExecutionContext executionContext, CallbackArg
 
 			if (pair.HasValue)
 				return DynValue.NewTuple(pair.Value.Key, pair.Value.Value);
-			else
-				throw new ScriptRuntimeException("invalid key to 'next'");
+
+			throw new ScriptRuntimeException("invalid key to 'next'");
 		}
 
 		// __next_i (table [, index])
@@ -76,17 +76,10 @@ public static DynValue __next_i(ScriptExecutionContext executionContext, Callbac
 			DynValue table = args.AsType(0, "!!next_i!!", DataType.Table);
 			DynValue index = args.AsType(1, "!!next_i!!", DataType.Number);
 
-			int idx = ((int)index.Number) + 1;
+			int idx = (int) index.Number + 1;
 			DynValue val = table.Table.Get(idx);
 
-			if (val.Type != DataType.Nil)
-			{
-				return DynValue.NewTuple(DynValue.NewNumber(idx), val);
-			}
-			else
-			{
-				return DynValue.Nil;
-			}
+			return val.Type != DataType.Nil ? DynValue.NewTuple(DynValue.NewNumber(idx), val) : DynValue.Nil;
 		}
 	}
 }

src/MoonSharp.Interpreter/CoreLib/TableModule.cs

@@ -41,7 +41,7 @@ public static DynValue pack(ScriptExecutionContext executionContext, CallbackArg
 			DynValue v = DynValue.NewTable(t);
 
 			for (int i = 0; i < args.Count; i++)
-				t.Set(i + 1, args[i]);
+				t.Set(i + executionContext.OwnerScript.Options.IndexTablesFrom, args[i]);
 
 			t.Set("n", DynValue.NewNumber(args.Count));
 
@@ -61,7 +61,7 @@ public static DynValue sort(ScriptExecutionContext executionContext, CallbackArg
 
 			List<DynValue> values = new List<DynValue>();
 
-			for (int i = 1; i <= end; i++)
+			for (int i = executionContext.OwnerScript.Options.IndexTablesFrom; i < end + executionContext.OwnerScript.Options.IndexTablesFrom; i++)
 				values.Add(vlist.Table.Get(i));
 
 			try
@@ -76,39 +76,34 @@ public static DynValue sort(ScriptExecutionContext executionContext, CallbackArg
 
 			for (int i = 0; i < values.Count; i++)
 			{
-				vlist.Table.Set(i + 1, values[i]);
+				vlist.Table.Set(i + executionContext.OwnerScript.Options.IndexTablesFrom, values[i]);
 			}
 
 			return vlist;
 		}
 
 		private static int SortComparer(ScriptExecutionContext executionContext, DynValue a, DynValue b, DynValue lt)
 		{
-			if (lt.IsNil())
-			{
-				lt = executionContext.GetBinaryMetamethod(a, b, "__lt");
-
-				if (lt.IsNil())
-				{
-					if (a.Type == DataType.Number && b.Type == DataType.Number)
-						return a.Number.CompareTo(b.Number);
-					if (a.Type == DataType.String && b.Type == DataType.String)
-						return a.String.CompareTo(b.String);
+			if (!lt.IsNil())
+				return LuaComparerToClrComparer(
+					executionContext.GetScript().Call(lt, a, b),
+					executionContext.GetScript().Call(lt, b, a));
+
+			lt = executionContext.GetBinaryMetamethod(a, b, "__lt");
 
-					throw ScriptRuntimeException.CompareInvalidType(a, b);
-				}
-				else
-				{
-					return LuaComparerToClrComparer(
-						executionContext.GetScript().Call(lt, a, b),
-						executionContext.GetScript().Call(lt, b, a));
-				}
-			}
-			else
-			{
+			if (!lt.IsNil())
 				return LuaComparerToClrComparer(
 					executionContext.GetScript().Call(lt, a, b),
 					executionContext.GetScript().Call(lt, b, a));
+
+			switch (a.Type)
+			{
+				case DataType.Number when b.Type == DataType.Number:
+					return a.Number.CompareTo(b.Number);
+				case DataType.String when b.Type == DataType.String:
+					return a.String.CompareTo(b.String);
+				default:
+					throw ScriptRuntimeException.CompareInvalidType(a, b);
 			}
 		}
 
@@ -144,20 +139,20 @@ public static DynValue insert(ScriptExecutionContext executionContext, CallbackA
 			if (vvalue.IsNil())
 			{
 				vvalue = vpos;
-				vpos = DynValue.NewNumber(len + 1);
+				vpos = DynValue.NewNumber(len + executionContext.OwnerScript.Options.IndexTablesFrom);
 			}
 
 			if (vpos.Type != DataType.Number)
 				throw ScriptRuntimeException.BadArgument(1, "table.insert", DataType.Number, vpos.Type, false);
 
-			int pos = (int)vpos.Number;
+			int pos = vpos.Int;
 
-			if (pos > len + 1 || pos < 1)
+			if (pos > len + 1 || pos < executionContext.OwnerScript.Options.IndexTablesFrom)
 				throw new ScriptRuntimeException("bad argument #2 to 'insert' (position out of bounds)");
 
 			for (int i = len; i >= pos; i--)
 			{
-				list.Set(i + 1, list.Get(i));
+				list.Set(i + executionContext.OwnerScript.Options.IndexTablesFrom, list.Get(i));
 			}
 
 			list.Set(pos, vvalue);
@@ -181,7 +176,7 @@ public static DynValue remove(ScriptExecutionContext executionContext, CallbackA
 
 			int pos = vpos.IsNil() ? len : (int)vpos.Number;
 
-			if (pos >= len + 1 || (pos < 1 && len > 0))
+			if (pos >= len + 1 || (pos < executionContext.OwnerScript.Options.IndexTablesFrom && len > 0))
 				throw new ScriptRuntimeException("bad argument #1 to 'remove' (position out of bounds)");
 
 			for (int i = pos; i <= len; i++)
@@ -210,24 +205,15 @@ public static DynValue concat(ScriptExecutionContext executionContext, CallbackA
 
 			Table list = vlist.Table;
 			string sep = vsep.IsNil() ? "" : vsep.String;
-			int start = vstart.IsNilOrNan() ? 1 : (int)vstart.Number;
-			int end; 
-
-			if (vend.IsNilOrNan())
-			{
-				end = GetTableLength(executionContext, vlist);
-			}
-			else 
-			{
-				end = (int)vend.Number;
-			}
+			int start = vstart.IsNilOrNan() ? executionContext.OwnerScript.Options.IndexTablesFrom : vstart.Int;
+			int end = vend.IsNilOrNan() ? GetTableLength(executionContext, vlist) : vend.Int;
 
 			if (end < start)
 				return DynValue.NewString(string.Empty);
 
 			StringBuilder sb = new StringBuilder();
 
-			for (int i = start; i <= end; i++)
+			for (int i = start; i < end + executionContext.OwnerScript.Options.IndexTablesFrom; i++)
 			{
 				DynValue v = list.Get(i);
 
@@ -250,21 +236,20 @@ private static int GetTableLength(ScriptExecutionContext executionContext, DynVa
 		{
 			DynValue __len = executionContext.GetMetamethod(vlist, "__len");
 
-			if (__len.IsNotNil())
+			if (!__len.IsNotNil())
 			{
-				DynValue lenv = executionContext.GetScript().Call(__len, vlist);
+				return vlist.Table.Length;
+			}
+
+			DynValue lenv = executionContext.GetScript().Call(__len, vlist);
 
-				double? len = lenv.CastToNumber();
+			double? len = lenv.CastToNumber();
 
-				if (len == null)
-					throw new ScriptRuntimeException("object length is not a number");
+			if (len == null)
+				throw new ScriptRuntimeException("object length is not a number");
+
+			return (int)len;
 
-				return (int)len;
-			}
-			else
-			{
-				return (int)vlist.Table.Length;
-			}
 		}
 	}
 

src/MoonSharp.Interpreter/DataStructs/Extension_Methods.cs

@@ -18,15 +18,9 @@ internal static class Extension_Methods
 		/// <returns></returns>
 		public static TValue GetOrDefault<TKey, TValue>(this Dictionary<TKey, TValue> dictionary, TKey key)
 		{
-			TValue v;
-
-			if (dictionary.TryGetValue(key, out v))
-				return v;
-
-			return default(TValue);
+			return dictionary.TryGetValue(key, out TValue v) ? v : default;
 		}
 
-
 		/// <summary>
 		/// Gets a value from the dictionary or creates it
 		/// </summary>
@@ -38,13 +32,13 @@ public static TValue GetOrDefault<TKey, TValue>(this Dictionary<TKey, TValue> di
 		/// <returns></returns>
 		public static TValue GetOrCreate<TKey, TValue>(this Dictionary<TKey, TValue> dictionary, TKey key, Func<TValue> creator)
 		{
-			TValue v;
-
-			if (!dictionary.TryGetValue(key, out v))
+			if (dictionary.TryGetValue(key, out TValue v))
 			{
-				v = creator();
-				dictionary.Add(key, v);
+				return v;
 			}
+
+			v = creator();
+			dictionary.Add(key, v);
 
 			return v;
 		}

src/MoonSharp.Interpreter/DataStructs/FastStack.cs

@@ -15,18 +15,16 @@ internal class FastStack<T> : IList<T>
 		int m_HeadIdx = 0;
 		private int maxCapacity;
 
+		public int Count => m_HeadIdx;
 		public int MaxCapacity => maxCapacity;
-
+		public ref T this[int index] => ref m_Storage[index];
+
 		public FastStack(int initialCapacity, int maxCapacity)
 		{
 			m_Storage = new T[initialCapacity];
 			this.maxCapacity = maxCapacity;
 		}
 
-		public ref T this[int index] => ref m_Storage[index];
-
-
-
 		void Grow(int newSize)
 		{
 			if (newSize < m_Storage.Length) return;
@@ -64,7 +62,7 @@ private void Zero(int from, int to)
 
 		private void Zero(int index)
 		{
-			m_Storage[index] = default(T);
+			m_Storage[index] = default;
 		}
 
 		public ref T Peek(int idxofs = 0)
@@ -88,7 +86,7 @@ public void RemoveLast( int cnt = 1)
 			if (cnt == 1)
 			{
 				--m_HeadIdx;
-				m_Storage[m_HeadIdx] = default(T);
+				m_Storage[m_HeadIdx] = default;
 			}
 			else
 			{
@@ -117,13 +115,6 @@ public void ClearSection(int index, int length)
 			Array.Clear(m_Storage, index, length);
 		}
 
-
-		public int Count
-		{
-			get { return m_HeadIdx; }
-		}
-
-
 		#region IList<T> Impl.
 
 		int IList<T>.IndexOf(T item)
@@ -143,14 +134,8 @@ void IList<T>.RemoveAt(int index)
 
 		T IList<T>.this[int index]
 		{
-			get
-			{
-				return this[index];
-			}
-			set
-			{
-				this[index] = value;
-			}
+			get => this[index];
+			set => this[index] = value;
 		}
 
 		void ICollection<T>.Add(T item)
@@ -173,15 +158,9 @@ void ICollection<T>.CopyTo(T[] array, int arrayIndex)
 			throw new NotImplementedException();
 		}
 
-		int ICollection<T>.Count
-		{
-			get { return this.Count; }
-		}
+		int ICollection<T>.Count => this.Count;
 
-		bool ICollection<T>.IsReadOnly
-		{
-			get { return false; }
-		}
+		bool ICollection<T>.IsReadOnly => false;
 
 		bool ICollection<T>.Remove(T item)
 		{