Ternary operator request

ruby-talk
1

Hi!

I'm more or less an amateur programmer, but I have fallen in love with Ruby.

I have an improvement idea for Ruby - I don't know if this is the best place to post this, but I thought it might spark some discussion about whether adding this "feature" would be healthy for the language or not.

Let's suppose we have a method called: "some_method?". Why not allow writing ternary operator expressions like this:

some_method? a : b

instead of

some_method? ? a : b

It feels way more natural,

Rob

2

That's a cute idea. I do find myself writing code like

something.zero? ? x : y

But presently there's nothing "special" about method names that end in "?" -
it's only conventional that they return a boolean, and they don't necessarily
have no arguments. In your example

some_method? a : b

how does ruby and the reader distinguish whether 'a' is

1) the first option for the ternary operator's return value or
2) the first argument to some_method?

As an example, this syntax doesn't look quite so appealing...

an_array.include? val x : y

alex

Robert Mannl wrote:

···

Hi!

I'm more or less an amateur programmer, but I have fallen in love with Ruby.

I have an improvement idea for Ruby - I don't know if this is the best place to post this, but I thought it might spark some discussion about whether adding this "feature" would be healthy for the language or not.

Let's suppose we have a method called: "some_method?". Why not allow writing ternary operator expressions like this:

some_method? a : b

instead of

some_method? ? a : b

It feels way more natural,

Rob

3

Hi --

Hi!

I'm more or less an amateur programmer, but I have fallen in love with Ruby.

Welcome!

I have an improvement idea for Ruby - I don't know if this is the best place to post this, but I thought it might spark some discussion about whether adding this "feature" would be healthy for the language or not.

Let's suppose we have a method called: "some_method?". Why not allow writing ternary operator expressions like this:

some_method? a : b

instead of

some_method? ? a : b

It feels way more natural,

I imagine it would be a nightmare to parse, for Ruby and for the human
eye.

   if x? 1 : 2; end

Is that:

   if x?(1) then 2; end

or

   if x? ? true : true; end

etc. (Not great examples, I know, but they indicate how vexed the ?
and : could get.)

I also think the two ?'s in question, though both ?'s, are really
semantically quite distinct.

There's always 'if' :slight_smile:

David

···

On Thu, 15 Sep 2005, Robert Mannl wrote:

--
David A. Black
dblack@wobblini.net

4

though this only works with the attribute type methods provided by traits:

   harp:~ > cat a.rb
   require 'traits'

   trait 'foo' => true

   puts( foo ? 'foo' : 'not foo' )
   puts( foo? ? 'foo' : 'not foo' )

   foo false

   puts( foo ? 'foo' : 'not foo' )
   puts( foo? ? 'foo' : 'not foo' )

   harp:~ > ruby a.rb
   foo
   not foo

cheers.

-a

···

On Thu, 15 Sep 2005, Robert Mannl wrote:

Hi!

I'm more or less an amateur programmer, but I have fallen in love with Ruby.

I have an improvement idea for Ruby - I don't know if this is the best place to post this, but I thought it might spark some discussion about whether adding this "feature" would be healthy for the language or not.

Let's suppose we have a method called: "some_method?". Why not allow writing ternary operator expressions like this:

some_method? a : b

instead of

some_method? ? a : b

--

email :: ara [dot] t [dot] howard [at] noaa [dot] gov
phone :: 303.497.6469
Your life dwells amoung the causes of death
Like a lamp standing in a strong breeze. --Nagarjuna

===============================================================================

5

I hadn't thought of that.

I'll try to wrap my mind around this later, but you seem to be right :slight_smile:

Rob