Community Experience With Iterators vs Overwriting

[jehugaleahsa@gmail.com]

Hello:

I was running some tests today and found an interesting result. I have
a large library where half the methods work on IEnumerable<T>
(Iterators similar to LINQ), and another that works on List<T>, using
indices to overwrite values.

I wanted to see which performed better overall (I guessed wrong). What
surprised me what that a well-written Iterator typically ran faster
(usually generating a new IEnumerable<U>) than a similar method that
just overwrites a List<T>.

Does anyone have a good explanation for why this is true? Is it just a
fluke on my part? And what does the community say about using one over
the other? I honestly think there is something beautiful about
Iterators and would like to use them more often than not.

Thanks for your input,
Travis

[Michael Starberg]

Re: Community Experience With Iterators vs Overwriting


<jehugaleahsa@g mail.comwrote in message
news:e27350c5-6199-412b-9f90-032f2b782e93@h1 1g2000prf.googl egroups.com...

Hello:
>
I was running some tests today and found an interesting result. I have
a large library where half the methods work on IEnumerable<T>
(Iterators similar to LINQ), and another that works on List<T>, using
indices to overwrite values.

ok.

>
I wanted to see which performed better overall (I guessed wrong). What
surprised me what that a well-written Iterator typically ran faster
(usually generating a new IEnumerable<U>) than a similar method that
just overwrites a List<T>.

Good for you.
But what is 'faster'?

Is performance a problem for you?

>
Does anyone have a good explanation for why this is true?

I have not.

Is it just a fluke on my part? And what does the community say about using
one over
the other?

I say use 'foreach' over 'for'.
Not because one is faster or not,
but just to get rid of the
'i <= list.Length' bugs.

Also it looks nicer. Much more readable.
Also with typing foreach and press tab, you can do a iterator very quickly.

With the common snippet over foreach, with the old snippet started with
'var',
I just had to write my own foreach-snippet, 'fe' that skips that first step.
Don't need to tab through 'var' with my snippet. 'var' is just fine for me
=)

I honestly think there is something beautiful about
Iterators and would like to use them more often than not.

I honsestly also think they are beautiful. May have to do something with
that I actaully have to maintain other peoples code!? =)
The for(init; expression; iter) is HighTech from the -70ies (60ies?). - Move
along folks, there is nothing to see here.. move along...

>
Thanks for your input,

Use foreach whenever you can.
And Never, Never and NEVER, do a myList.ForEach( lambda =lambda.whateve r
== 'something');

... that is just plain ugly!

foreach is your friend!

Travis

Happy Coding
- Michael Starberg