/DLR_Main/Languages/IronPython/IronPython.Modules/_ctypes/Array.cs

/* ****************************************************************************

 *

 * Copyright (c) Microsoft Corporation. 

 *

 * This source code is subject to terms and conditions of the Apache License, Version 2.0. A 

 * copy of the license can be found in the License.html file at the root of this distribution. If 

 * you cannot locate the  Apache License, Version 2.0, please send an email to 

 * dlr@microsoft.com. By using this source code in any fashion, you are agreeing to be bound 

 * by the terms of the Apache License, Version 2.0.

 *

 * You must not remove this notice, or any other, from this software.

 *

 *

 * ***************************************************************************/



using System;

using System.Collections;

using System.Text;



using Microsoft.Scripting.Runtime;



using IronPython.Runtime;

using IronPython.Runtime.Operations;

using IronPython.Runtime.Types;

using System.Collections.Generic;



#if CLR2

using Microsoft.Scripting.Math;

#else

using System.Numerics;

#endif



#if !SILVERLIGHT

namespace IronPython.Modules {

    /// <summary>

    /// Provides support for interop with native code from Python code.

    /// </summary>

    public static partial class CTypes {

        

        [PythonType("Array")]

        public abstract class _Array : CData {



            public void __init__(params object[] args) {

                INativeType nativeType = NativeType;



                _memHolder = new MemoryHolder(nativeType.Size);



                if (args.Length > ((ArrayType)nativeType).Length) {

                    throw PythonOps.IndexError("too many arguments");

                }

                nativeType.SetValue(_memHolder, 0, args);

            }



            public object this[int index] {

                get {

                    index = PythonOps.FixIndex(index, ((ArrayType)NativeType).Length);

                    INativeType elementType = ElementType;

                    return elementType.GetValue(

                        _memHolder,

                        this,

                        checked(index * elementType.Size),

                        false

                    );

                }

                set {

                    index = PythonOps.FixIndex(index, ((ArrayType)NativeType).Length);

                    INativeType elementType = ElementType;



                    object keepAlive = elementType.SetValue(

                        _memHolder,

                        checked(index * elementType.Size),

                        value

                    );



                    if (keepAlive != null) {

                        _memHolder.AddObject(index.ToString(), keepAlive);

                    }

                }

            }



            public object this[[NotNull]Slice slice] {

                get {

                    int start, stop, step;

                    int size = ((ArrayType)NativeType).Length;

                    SimpleType elemType = ((ArrayType)NativeType).ElementType as SimpleType;



                    slice.indices(size, out start, out stop, out step);

                    if ((step > 0 && start >= stop) || (step < 0 && start <= stop)) {

                        if (elemType != null && (elemType._type == SimpleTypeKind.WChar || elemType._type == SimpleTypeKind.Char)) {

                            return String.Empty;

                        }

                        return new List();

                    }



                    int n = (int)(step > 0 ? (0L + stop - start + step - 1) / step : (0L + stop - start + step + 1) / step);

                    if (elemType != null && (elemType._type == SimpleTypeKind.WChar || elemType._type == SimpleTypeKind.Char)) {

                        int elmSize = ((INativeType)elemType).Size;

                        StringBuilder res = new StringBuilder(n);



                        for (int i = 0, index = start; i < n; i++, index += step) {

                            char c = elemType.ReadChar(_memHolder, checked(index * elmSize));

                            res.Append(c);

                        }



                        return res.ToString();

                    } else {

                        object[] ret = new object[n];

                        int ri = 0;

                        for (int i = 0, index = start; i < n; i++, index += step) {

                            ret[ri++] = this[index];

                        }



                        return new List(ret);

                    }

                }

                set {

                    int start, stop, step;

                    int size = ((ArrayType)NativeType).Length;

                    SimpleType elemType = ((ArrayType)NativeType).ElementType as SimpleType;



                    slice.indices(size, out start, out stop, out step);



                    int n = (int)(step > 0 ? (0L + stop - start + step - 1) / step : (0L + stop - start + step + 1) / step);

                    IEnumerator ie = PythonOps.GetEnumerator(value);

                    for (int i = 0, index = start; i < n; i++, index += step) {

                        if (!ie.MoveNext()) {

                            throw PythonOps.ValueError("sequence not long enough");

                        }

                        this[index] = ie.Current;

                    }



                    if (ie.MoveNext()) {

                        throw PythonOps.ValueError("not all values consumed while slicing");

                    }

                }

            }



            public int __len__() {

                return ((ArrayType)NativeType).Length;

            }



            private INativeType ElementType {

                get {

                    return ((ArrayType)NativeType).ElementType;

                }

            }



            

            internal override PythonTuple GetBufferInfo() {

                INativeType elemType = ElementType;

                int dimensions = 1;

                List<object> shape = new List<object>();

                shape.Add((BigInteger)__len__());

                while (elemType is ArrayType) {

                    dimensions++;

                    shape.Add((BigInteger)((ArrayType)elemType).Length);

                    elemType = ((ArrayType)elemType).ElementType;

                }





                return PythonTuple.MakeTuple(

                    NativeType.TypeFormat,

                    dimensions,

                    PythonTuple.Make(shape)

                );

            }

        }

    }

}

#endif