#type-inference

How to: How can I reliably determine the type of a variable that is declared using var at design time?

How can I reliably determine the type of a variable that is declared using var at design time?

I’m working on a completion (intellisense) facility for C# in emacs.

The idea is, if a user types a fragment, then asks for completion via a particular keystroke combination, the completion facility will use .NET reflection to determine the possible completions.

Doing this requires that the type of the…

How to: What limits does scala place on the "acceptable complexity" of inferred types?

What limits does scala place on the "acceptable complexity" of inferred types?

According to the Scala Language Spec:

… local type inference is permitted to limit the complexity of inferred bounds [of type parameters]. Minimality and maximality of types have to be understood relative to the set of types of acceptable complexity.

In practice what are the limits?

Also, are there different limits…

Fixed Use of var keyword in C# #dev #it #asnwer

Use of var keyword in C#

After discussion with colleagues regarding the use of the ‘var’ keyword in C# 3 I wondered what people’s opinions were on the appropriate uses of type inference via var?

For example I rather lazily used var in questionable circumstances, e.g.:-

foreach(var item in someList) { // ... } // Type of 'item' not clear. var something = someObject.SomeProperty; // Type of…

How to: Collections.emptyList() returns a List?

Collections.emptyList() returns a List<Object>?

I’m having some trouble navigating Java’s rule for inferring generic type parameters. Consider the following class, which has an optional list parameter:

import java.util.Collections; import java.util.List; public class Person { private String name; private List nicknames; public Person(String name) { this(name,Collections.emptyList()); } public…

How to: Use of var keyword in C#

Use of var keyword in C#

After discussion with colleagues regarding the use of the ‘var’ keyword in C# 3 I wondered what people’s opinions were on the appropriate uses of type inference via var?

For example I rather lazily used var in questionable circumstances, e.g.:-

foreach(var item in someList) { // ... } // Type of 'item' not clear. var something = someObject.SomeProperty; // Type of…

So Type Inference is pretty cool, so are Extension Methods. And of course Fluent APIs help making code that calls your API look beter and more readable.

My colleague Martijn works on NEST, a .NET client for elasticsearch written in C#. I occasionally help him out and we discus design patterns like these fluent APIs. But he ran into a problem a while ago, which we couldn't figure out a solution to, so we let things rest.

Working on a pet project I discovered that you can make Extenstion method generic and it got me thinking...

My efforts resulted in a github repo with test code and a very long stackoverflow question http://stackoverflow.com/questions/16442596/extension-methods-and-type-inference.