using

System;

using

System.Threading;

using

System.Collections.Generic;

using

System.Diagnostics;

namespace

DuckTyping

{

class

Program

{

public

static

int

Range

=

10000000

;

static

void

Main(

string

[] args)

{

string

newRange

=

Console.ReadLine();

if

(

!

string

.IsNullOrEmpty(newRange))

{

Range

=

Int32.Parse(newRange);

}

FakeEnumerable fake

=

new

FakeEnumerable();

RealEnumerable real

=

new

RealEnumerable();

YieldEnumerable

yield

=

new

YieldEnumerable();

Stopwatch sw

=

new

Stopwatch();

sw.Start();

foreach

(var item

in

fake)

{

}

sw.Stop();

Console.WriteLine(

"

Duck Typing : {0}

"

,sw.ElapsedMilliseconds);

sw.Reset();

sw.Start();

foreach

(var item

in

real)

{

}

sw.Stop();

Console.WriteLine(

"

Interface compl: {0}

"

, sw.ElapsedMilliseconds); sw.Reset();

sw.Reset();

sw.Start();

foreach

(var item

in

yield

)

{

}

sw.Stop();

Console.WriteLine(

"

Yield compl: {0}

"

, sw.ElapsedMilliseconds);

Console.ReadKey();

}

}

public

class

FakeEnumerable

{

public

FakeEnumerator GetEnumerator()

{

return

new

FakeEnumerator();

}

}

public

class

FakeEnumerator

{

public

FakeEnumerator()

{

this

.Current

=

1

;

}

public

int

Current {

get

;

set

;}

public

bool

MoveNext()

{

Current

++

;

return

Current

<

Program.Range;

}

}

public

class

RealEnumerable : IEnumerable

<

int

>

{

public

IEnumerator

<

int

>

GetEnumerator()

{

return

new

RealEnumerator();

}

System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()

{

throw

new

NotImplementedException();

}

}

public

class

RealEnumerator : IEnumerator

<

int

>

{

private

int

current;

public

RealEnumerator()

{

this

.current

=

0

;

}

public

int

Current

{

get

{

return

this

.current; }

}

public

void

Dispose()

{

}

object

System.Collections.IEnumerator.Current

{

get

{

return

this

.current; }

}

public

bool

MoveNext()

{

current

++

;

return

current

<

Program.Range;

}

public

void

Reset()

{

throw

new

NotImplementedException();

}

}

public

class

YieldEnumerable : IEnumerable

<

int

>

{

private

static

int

index

=

0

;

public

IEnumerator

<

int

>

GetEnumerator()

{

while

(index

<

Program.Range)

yield

return

index

++

;

}

System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()

{

throw

new

NotImplementedException();

}

}

}