In my youth I once attended a lecture given by Brian Kernighan on the subject of code quality, which was very influential on my attitudes towards writing legible code. One of the things that Kernighan recommended was to endeavour write code that was so clear that it could be easily read over the phone and understood. Most people find code much easier to comprehend when read than when heard; if you can make it clear enough to be understood when heard, it’s probably pretty clear code.
I was reminded of this when I got the following question from a colleague by email:
Subject: Stupid C# 3.0 lambda expression question How does one read the => operator?
Subject: Stupid C# 3.0 lambda expression question
How does one read the => operator?
First off, I told my colleague that there are no stupid questions, only stupid people. No stupid people work here, so don’t stress about it. This is a perfectly sensible question.
As far as I know, we do not have an “official” line on how to read this operator over the phone. In the absense of any other context, I personally would say c=>c+1 as “see goes to see plus one”. Some variations that I’ve heard:
For a projection, (Customer c)=>c.Name: “customer see becomes see dot name”
For a predicate, (Customer c)=>c.Age > 21: “customer see such that see dot age is greater than twenty-one”
An unfortunate conflation is that the => operator looks a lot like ⇒, the “implies” operator in mathematics. Since => does not have the same semantics as ⇒, it is probably a bad idea to read => as “implies”. (x⇒y would have the semantics of !x|y in C#.)
Incidentally, it is a little known fact that VB6 and VBScript implemented the ⇒ operator with the Imp keyword and the ⇔ operator with the Eqv keyword. They disappeared in VB.NET. Where did they go? It is a mystery!