Comment by klysm
4 days ago
This isn’t a great example of what linq is good at. There’s no reason to do ToList there, and the ForEach isn’t particularly idiomatic
4 days ago
This isn’t a great example of what linq is good at. There’s no reason to do ToList there, and the ForEach isn’t particularly idiomatic
Yeah, I hit the problem that there isn't a null-type equivalent of Select() for Action<T>, nor is there a IEnumerable.ForEach (controversial), so that's a bit of a hack. But I wanted to make it as close to the original example as possible.
> There’s no reason to do ToList there
In this case, I would move it to the very end if we are concerned about the underlying data shifting when the collection is actually enumerated.
Forgetting to materialize LINQ results can cause a lot of trouble, oftentimes in ways that happily evade detection while a debugger is attached.
> if we are concerned about the underlying data shifting when the collection is actually enumerated
I’m not sure what you mean by this. You can fulfill the IEnumerable contract without allowing multiple enumerations, but that doesn’t really have to do with the data shifting around. Doing ToList can be an expensive and unnecessary allocation
Imagine a live SQL query you are subsequently filtering with LINQ.
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Yes, ForEach isn't idiomatic but he could use Select instead.
Side effects in a Select is not idiomatic either