Add section about Yoda conditions

[camsaul]

Consider two ways to check what sort of bird we have on hand:

1. (= bird-type :toucan) -- one reads this code as "bird type equals toucan"
2. (= :toucan bird-type) -- you'd read this as "toucan equals bird type"

Now while they both do exactly the same thing, the former is the "normal" way to write things and the latter is a Yoda condition

[seancorfield]

I don't find anything wrong with 2. and it has specific benefits in many languages because having the constant first avoids this error:

if ( x = 2 ) { ... } // assignment

if ( 2 = x ) { ... } // compiler will catch this as an error!

if ( 2 == x ) { ... } // what was actually intended

So you'll likely find a lot of people who've had that drummed into them for years and it'll be natural for them to write:

(if (= 2 x) ...)

(and I do this myself, very deliberately)

[memark]

and it has specific benefits in many languages

Those are also known as "badly designed languages". Wouldn't it be great to be rid of those practices now that we're actually using a language as good as Clojure? :)