What do you call this in Ruby?

This sums up what I dislike most about Scala (which is an even worse offender in this regard). A rule of thumb: if a 10-year-old wouldn't be able to intuitively read the operator, use words.

greydius3• 10 years ago

Written words are symbols as well. What should we do when we don't understand words?

kibwen2• 10 years ago

We Google them, which is an impossible task for non-alphabetic symbols. :P

incepted2• 10 years ago

Slippery slope argument.

I like the Litmus test that a ten year old should be able to read them, which means that +, *, / and - are fine but =~> and other nonsense should be banned.

PeCaN• 10 years ago

Pfft try Haskell sometime.

Everything that's even remotely Applicative seems to have a tendency to export 20 variations of <*>.

Then there's Lenses, the coolest line noise you'll ever see.

jowiar4• 10 years ago

Yep. Haskellians invaded the early Scala community, crapping on codebases everywhere.

ssmoot2• 10 years ago

People say that. But it's totally misguided IME. You're talking about scalaz.

Normal Scala code has fewer symbols than Ruby aside from function lifting (the underscore).

In fact, you've got Generics (square braces), curly braces for blocks, fatty arrows for call-by-name, functions parameters and pattern matching. Parens for methods and tuples. Underscore for function lifting. cons (double or triple colon). Stab by arrows as an optional shorthand infix notation for creating Pairs AKA Tuple2.

Every once in a blue moon you might see :+ to mean add a single item.

You can write a whole heckuva lot of Scala and never use much more than that. If you're facing symbolic overload then you should probably reevaluate the libraries you're using.

The only ones I use frequently that add anything else are spray-routing/akka-http's Route.~ to concatinate routes and json4s's JObject.~ to concatinate two objects together.

Yes there's a world of libraries that add a lot more, but they're entirely optional. You aren't a bad programmer if you do or do not use scalaz. (At least I don't consider myself a bad one, and I don't.)

Scala itself doesn't actually extend all that far beyond c#. The FUD around symbols in Scala is just that. You add cons, the occasional stabby arrow and the underscore and you've got the extent of Scala's additions you'll find in your average library.

I just do not get how people walk away with this impression. Especially Rubyists where ivars, cvars, pipe characters, two different HashMap styles etc is in everyday code.

IME Scala developers in-training don't actually have much trouble with this stuff. What they have trouble with is pattern-matching structure and function composition.

But Ruby can't do either.

In fact, other than the ability to invent more complex DSLs with more symbols I'm not actually sure that there's anything Ruby does better. Or more consistently.

jowiar4• 10 years ago

The problem is that having Scalaz and its ilk underpinning a lot of libraries mean that, if you need to go down the debugging stack, you find yourself pretty quickly in squiggle soup.

krotton• 10 years ago

SBT's the worst offender.

technion• 10 years ago

I had a Microsoft support technician ask us to press the "flower button" in a powershell script. It took a while to work out he meant { and }.

broodbucket• 10 years ago

Wish I worked with a language with a === operator so I could say "threequals". Very clever and fitting.

BigJono• 10 years ago

I've worked with Javascript for years and never thought of this. Such wasted opportunity...

cdcarter2• 10 years ago

'!!' -> "truthy?"

MichaelApproved4• 10 years ago

! -> "not truthy". So !! means "not 'not truthy'" which is truthy.

Truthy is something that isn't exactly a true boolean but will equate to true(thy) when evaluated with this type of comparison. Things like undefined, null, and empty string will not be truthy.

More info on what's truthy (for JavaScript at least) is here http://james.padolsey.com/javascript/truthy-falsey/

edit: typically, if you want to test for truthy, you'll just evaluate it like so

if (my_object) { //truthy }else{ //not truthy }

Does anyone know a time when you'd use !! instead of just the object in the evaluation? I'm not a Ruby dev, so I don't know specific cases for needing !!

cdcarter2• 10 years ago

Yep, I thought it was a common enough idiom in Ruby as well that it might belong on the list!

tinco• 10 years ago

Generally when you prepare a value for serialization. In my ~8 years of Ruby I've only used !! a few times. I think all those times had to do with configuration and/or serialization. For example:

```

    my_option = !!ENV[MY_OPTION] # is false when not set
    puts "my_option is: #{my_option}"

```

Stratoscope• 10 years ago

One typical use for !! in JavaScript or Ruby is where a function/method returns a boolean value that indicates the presence or absence of an object.

You could just use:

  return myObject;

Since that value will be truthy or falsy, any code that tests it will generally work, as your if statement example demonstrates.

But there are two advantages to doing this instead:

  return !! myObject;

1) Now you are returning an actual boolean value, not just a truthy/falsy value.

2) Sometimes more importantly, you are now releasing this function's reference to the object, instead of possibly keeping that reference around much longer than needed and preventing it from being garbage collected.

kbenson2• 10 years ago

In other words, "cast to boolean"

eru4• 10 years ago

A select few operators (out of hundreds) for a single Haskell library: https://github.com/ekmett/lens/wiki/Operators

(For full disclosure, the lens library is infamous for this.)

kccqzy• 10 years ago

You are perfectly fine importing the module Control.Lens.Combinators[0], which has the full functionality of lens except the operators. There's nothing you can do with operators but can't do with normal functions named with words.

[0] http://ekmett.github.io/lens/src/Control-Lens-Combinators.ht...

eru4• 10 years ago

Oh, definitely. Haskell approach to operators and overloading is exactly the Right Way: operators are weirdly syntaxed function, and you can add your own. No need to make bit-shifting do IO.

santaclaus• 10 years ago

=~

Cigarette operator! This list is on fire.

kbenson2• 10 years ago

Such little imagination... You should learn from your forefathers. Quantity is no substitute for quality. ;)

http://search.cpan.org/dist/perlsecret/lib/perlsecret.pod#SY...

Bluestrike2• 10 years ago

It would seem like the forefathers won this round. You've got to love the inchworm on a stick.

dward• 10 years ago

    =( )=  goatse operator

cannot unsee.

teddyh• 10 years ago

Normal single-character operators also have names:

http://www.catb.org/jargon/html/A/ASCII.html

biot• 10 years ago

How did hashrocket get named? I would think instead of => a hashrocket would look like: #>

edit: Makes total sense. Thanks for the replies.

Cerium• 10 years ago

I understand that it is the rocket shaped operator used in making hashes.

{:cats => "foo"}

arjie• 10 years ago

Ruby's associative arrays are called hashes. That operator is how you assign a value to a key.

gregschlom• 10 years ago

my favorite is the "Elvis operator" in kotlin ?:

Took me a while to figure out why it was called that way.

brandonbloom2• 10 years ago

Meanwhile:

    Mathematica 10.0 for Mac OS X x86 (64-bit)
    Copyright 1988-2014 Wolfram Research, Inc.

    In[1]:= FullForm[x->y*z^w]

    Out[1]//FullForm= Rule[x, Times[y, Power[z, w]]]

    In[2]:= x\[UnionPlus]y\[RightTee]z

    Out[2]= x ⊎ y ⊢ z

There's no reason your programming language shouldn't be able to tell you what these things are called in English without an external reference.

Skywing2• 10 years ago

Or is there? queue x-files theme song

eru4• 10 years ago

Some operators are so abstract that they don't really have a good name.

Eg if you are talking about groups in general, how do you pronounce the group operation ∘? At uni, we usually just called it Kringel.

brandonbloom2• 10 years ago

The name can be arbitrary, as long as it's unambiguous. By the way, here's what mathematica says when I copy paste that and enter x∘y: SmallCircle[x,y]

Also fun:

    In[3]:= SpokenString[x\[SmallCircle]y]
    Out[3]= "SmallCircle of x and y"

Which can be turned in to sound:

    Speak[x\[SmallCircle]y]

jack9• 10 years ago

... is an ellipsis.

! is enunciated as "bang" from BASH parlance, iirc.

juanfatas2• 10 years ago

thank you, added.

dasil003• 10 years ago

stabby lambda is my favorite.

ilikepi• 10 years ago

I like the name "stabby lambda", but I dislike its use. It seems less readable to me. The again I also think ruby 1.9 Hash syntax is less readable, so maybe my judgement is suspect.

Skywing2• 10 years ago

dat bacon cannon

zyxley• 10 years ago

This seems like it could have been prime territory for a bit of surrealist/meta fiction, with gradually stranger descriptions of operators turning into a short story of some kind.

mokus• 10 years ago

Looks like quite a few of these were cribbed from the intercal character set[0]. Nice to see that living on.

[0] http://www.muppetlabs.com/~breadbox/intercal-man/tonsila.htm...

clairity• 10 years ago

i like the yoda operator: !!!

i've never used it... what's a good use case?

What do you call this in Ruby?

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