C# DynamicMetaObject.Clone方法代码示例

        private static DynamicMetaObject MakeUnindexableError(DynamicMetaObjectBinder operation, PythonIndexType op, DynamicMetaObject/*!*/[] types, DynamicMetaObject indexedType, PythonContext state) {
            DynamicMetaObject[] newTypes = (DynamicMetaObject[])types.Clone();
            newTypes[0] = indexedType;

            PythonTypeSlot dummySlot;
            if (op != PythonIndexType.GetItem &&
                op != PythonIndexType.GetSlice &&
                DynamicHelpers.GetPythonType(indexedType.Value).TryResolveSlot(state.SharedContext, "__getitem__", out dummySlot)) {
                // object supports indexing but not setting/deletion
                if (op == PythonIndexType.SetItem || op == PythonIndexType.SetSlice) {
                    return TypeError(operation, "'{0}' object does not support item assignment", newTypes);
                } else {
                    return TypeError(operation, "'{0}' object doesn't support item deletion", newTypes);
                }
            }
            return TypeError(operation, "'{0}' object is unsubscriptable", newTypes);
        }

        private static DynamicMetaObject/*!*/ GetGetOrDeleteSlice(PythonContext state, DynamicMetaObject/*!*/[]/*!*/ args) {
            DynamicMetaObject[] newArgs = (DynamicMetaObject[])args.Clone();
            for (int i = 1; i < newArgs.Length; i++) {
                if (!IsIndexType(state, newArgs[i])) {
                    newArgs[i] = newArgs[i].Restrict(newArgs[i].GetLimitType());
                }
            }

            return new DynamicMetaObject(
                Ast.Call(
                    typeof(PythonOps).GetMethod("MakeSlice"),
                    AstUtils.Convert(GetGetOrDeleteParameter(newArgs, 1), typeof(object)),
                    AstUtils.Convert(GetGetOrDeleteParameter(newArgs, 2), typeof(object)),
                    AstUtils.Convert(GetGetOrDeleteParameter(newArgs, 3), typeof(object))
                ),
                BindingRestrictions.Combine(newArgs)
            );
        }

        /// <summary>
        /// Python has three protocols for slicing:
        ///    Simple Slicing x[i:j]
        ///    Extended slicing x[i,j,k,...]
        ///    Long Slice x[start:stop:step]
        /// 
        /// The first maps to __*slice__ (get, set, and del).  
        ///    This takes indexes - i, j - which specify the range of elements to be
        ///    returned.  In the slice variants both i, j must be numeric data types.  
        /// The 2nd and 3rd are both __*item__.  
        ///    This receives a single index which is either a Tuple or a Slice object (which 
        ///    encapsulates the start, stop, and step values) 
        /// 
        /// This is in addition to a simple indexing x[y].
        /// 
        /// For simple slicing and long slicing Python generates Operators.*Slice.  For
        /// the extended slicing and simple indexing Python generates a Operators.*Item
        /// action.
        /// 
        /// Extended slicing maps to the normal .NET multi-parameter input.  
        /// 
        /// So our job here is to first determine if we're to call a __*slice__ method or
        /// a __*item__ method.  
        /// </summary>
        private static DynamicMetaObject/*!*/ MakeIndexerOperation(DynamicMetaObjectBinder/*!*/ operation, PythonIndexType op, DynamicMetaObject/*!*/[]/*!*/ types, DynamicMetaObject errorSuggestion) {
            string item, slice;
            DynamicMetaObject indexedType = types[0].Restrict(types[0].GetLimitType());
            PythonContext state = PythonContext.GetPythonContext(operation);
            BuiltinFunction itemFunc = null;
            PythonTypeSlot itemSlot = null;
            bool callSlice = false;
            int mandatoryArgs;

            GetIndexOperators(op, out item, out slice, out mandatoryArgs);

            if (types.Length == mandatoryArgs + 1 && IsSlice(op) && HasOnlyNumericTypes(operation, types, op == PythonIndexType.SetSlice)) {
                // two slice indexes, all int arguments, need to call __*slice__ if it exists
                callSlice = BindingHelpers.TryGetStaticFunction(state, slice, indexedType, out itemFunc);
                if (itemFunc == null || !callSlice) {
                    callSlice = MetaPythonObject.GetPythonType(indexedType).TryResolveSlot(state.SharedContext, slice, out itemSlot);
                }
            }

            if (!callSlice) {
                // 1 slice index (simple index) or multiple slice indexes or no __*slice__, call __*item__, 
                if (!BindingHelpers.TryGetStaticFunction(state, item, indexedType, out itemFunc)) {
                    MetaPythonObject.GetPythonType(indexedType).TryResolveSlot(state.SharedContext, item, out itemSlot);
                }
            }

            // make the Callable object which does the actual call to the function or slot
            Callable callable = Callable.MakeCallable(state, op, itemFunc, itemSlot);
            if (callable == null) {
                return errorSuggestion ?? MakeUnindexableError(operation, op, types, indexedType, state);
            }

            // prepare the arguments and make the builder which will
            // call __*slice__ or __*item__
            DynamicMetaObject[] args;
            IndexBuilder builder;
            if (callSlice) {
                // we're going to call a __*slice__ method, we pass the args as is.
                Debug.Assert(IsSlice(op));

                builder = new SliceBuilder(types, callable);

                // slicing is dependent upon the types of the arguments (HasNumericTypes) 
                // so we must restrict them.
                args = ConvertArgs(types);
            } else {
                // we're going to call a __*item__ method.
                builder = new ItemBuilder(types, callable);
                if (IsSlice(op)) {
                    // we need to create a new Slice object.
                    args = GetItemSliceArguments(state, op, types);
                } else {
                    // no need to restrict the arguments.  We're not
                    // a slice and so restrictions are not necessary
                    // here because it's not dependent upon our types.
                    args = (DynamicMetaObject[])types.Clone();

                    // but we do need to restrict based upon the type
                    // of object we're calling on.
                    args[0] = types[0].Restrict(types[0].GetLimitType());
                }

            }

            return builder.MakeRule(operation, state, args);
        }