I am working on a library for C++ which is small, has no dependencies other than itself (i'm not using boost), works on all platforms, and most importantly is as friendly as C#.
This morning I finished testing my C++ implementation of linq. Here is an example of what it looks like. Your feedback is appreciated:
Edit: I expanded the examples
// Enumerable queries in C++
// This program searches the current directory
// And selects results using expression nodes
#include <Codebot/Packages/System.h>
#include <Codebot/Packages/Expressions.h>
using namespace Codebot;
using namespace Codebot::IO;
using namespace Codebot::Text;
using namespace Codebot::Expressions;
void TestFileFind()
{
String SearchPath = "*";
if (Application::Args().Length() > 0)
SearchPath = Application::Args()[0];
FileFind find;
find.Search(SearchPath);
auto query = Query(find)
.OrderBy([] (FileResult a, FileResult b)
{
if (a.Attributes.Contains(FileAttribute::Directory))
{
if (b.Attributes.Contains(FileAttribute::Directory))
return a.Name < b.Name;
return true;
}
if (b.Attributes.Contains(FileAttribute::Directory))
return false;
return a.Name < b.Name;
});
ForEach(item, query)
WriteLine(item.ToString());
auto bytes = query
.Select<int>([] (FileResult a) { return a.Size; })
.Sum();
WriteLine("{0|-31} total bytes\n", bytes);
}
void TestNumbers()
{
Array<int> numbers = {7, 4, 2, 8, 3, 6};
auto q = Query(numbers);
WriteLine("The first value is {0}",
q.FirstOrDefault());
WriteLine("The count value is {0}",
q.Count());
WriteLine("The sum value is {0}",
q.Where([] (int i) { return IsOdd(i); }).Sum());
WriteLine("The average value is {0}",
q.Average());
WriteLine("The min value is {0}",
q.Min());
WriteLine("The max value is {0}",
q.Max());
q = q.Where([] (int i) { return i > 2 && i < 8; })
.OrderBy([] (int a, int b) { return a > b; });
WriteLine("List: {0:list}\n", q);
}
void TestStrings()
{
Array<String> names = {"John", "Terrance", "Ralph", "Carl", "Stanley"};
auto q = Query(names);
WriteLine("The first value is {0}",
q.FirstOrDefault());
WriteLine("There are {0} items",
q.Count());
WriteLine("The sum is {0}", q
.Where([] (String s) { return s.Contains("a"); }).Sum());
WriteLine("The minimum value is {0}",
q.Min());
WriteLine("The maximum value is {0}",
q.Max());
q = q.Where([] (String s) { return s > "Mary"; })
.OrderBy([] (String a, String b) { return a.Length() < b.Length(); });
WriteLine("List: {0:list}\n", q);
}
int main()
{
return Application::Run({TestFileFind, TestNumbers, TestStrings});
}
/*
Output:
. Dir
.. Dir
Debug Dir
.cproject 14030 2012-04-12 14:41:33
.project 2508 2012-04-14 08:20:42
Person.h 1726 2012-04-12 22:59:28
Widget.cpp 871 2012-04-12 01:34:43
Widget.h 1663 2012-04-12 22:59:36
main.cpp 2415 2012-04-15 20:32:45
23213 total bytes
The first value is 7
The count value is 6
The sum value is 10
The average value is 5
The min value is 2
The max value is 8
List: {7, 6, 4, 3}
The first value is John
There are 5 items
The sum is TerranceRalphCarlStanley
The minimum value is Carl
The maximum value is Terrance
List: {Ralph, Stanley, Terrance}
*/
