Month: September 2009

An object lesson in blogging and accuracy; was: Efficient "vote counting" with LINQ to Objects – and the value of nothing

By jonskeet

Well, this is embarrassing. Yesterday evening, I excitedly wrote a blog post about an interesting little idea for making a particular type of LINQ query (basically vote counting) efficient. It was an idea that had occurred to me a few months back, but I hadn’t got round to blogging about it. The basic idea was to take a completely empty struct, and use that as the element type in the results of a grouping query – as the struct was empty, it would take no space, therefore "huge" arrays could be created for no cost beyond the fixed array overhead, … Continue reading An object lesson in blogging and accuracy; was: Efficient "vote counting" with LINQ to Objects – and the value of nothing

API design: choosing between non-ideal options

By jonskeet

So, UnconstrainedMelody is coming on quite nicely. It now has quite a few useful options for flags enums, "normal enums" and delegates. However, there are two conflicting limitations which leave a couple of options. (Other related answers on Stack Overflow have suggested alternative approaches, basically.) Currently, most of the enums code is in two classes: Flags and Enums. Both are non-generic: the methods within them are generic methods, so they have type parameters (and constraints). The main benefit of this is that generic type inference only applies to generic methods, and I definitely want that for extension methods and anywhere … Continue reading API design: choosing between non-ideal options

Generic constraints for enums and delegates

By jonskeet

As most readers probably know, C# prohibits generic type constraints from referring to System.Object, System.Enum, System.Array, System.Delegate and System.ValueType. In other words, this method declaration is illegal: public static T[] GetValues<T>() where T : struct, System.Enum {     return (T[]) Enum.GetValues(typeof(T)); } This is a pity, as such a method could be useful. (In fact there are better things we can do… such as returning a read-only collection. That way we don’t have to create a new array each time the method is called.) As far as I can tell, there is no reason why this should be prohibited. Eric Lippert … Continue reading Generic constraints for enums and delegates

Recent activities

By jonskeet

It’s been a little while since I’ve blogged, and quite a lot has been going on. In fact, there are a few things I’d have blogged about already if it weren’t for “things” getting in the way. Rather than writing a whole series of very short blog posts, I thought I’d wrap them all up here… C# in Depth: next MEAP drop available soon – Code Contracts Thanks to everyone who gave feedback on my writing dilemma. For the moment, the plan is to have a whole chapter about Code Contracts, but not include a chapter about Parallel Extensions. My … Continue reading Recent activities