Variables in String interpolation go against common practice

[gaffneyc]

Mainly looking at #1a4ebd4a where it suggests removing { } around variables when doing string interpolation. I don't feel it's common practice and suggesting it might cause confusion.

This came up today when a developer who's been working with ruby for about 2 years was surprised that you could even do #@variable interpolation. Seems to me that if it was in common practice he should have run into this style at least once in those two years.

[ethicalhack3r]

Out of curiosity how do you deal with having a string straight after the variable when using string interpolation without { }?

Example with { }:

puts "#{@variable}string_straight_after_without_space"

Example without { }:

puts "#@variablestring_straight_after_without_space"

The above wouldn't work as it would consume string_straight_after_without_space as the variable name. Or in this case is not having { } mandatory? or am I missing something?

[gaffneyc]

@ethicalhack3r I believe the only way to get around that is to add { }. So if the style of dropping { } stands then it should probably have a caveat added. I'd prefer to just reverse the suggestion to always add { } even if it's just a single variable.

[bbatsov]

@gaffneyc You're making an interesting point. I've noticed that most experienced Ruby hackers tend to use #@var, but there are quite few of those around, so indeed - a lot of people are simply not aware of the syntax. On a related note - I rarely find the need to interpolate an instance variable; most of the time I seem to be interpolating local vars and method call results.

@ethicalhack3r Good example. Have been coding Ruby for a long while, never had to do something like. I'll definitely mention it as an exception to the rule.

I'll leave this issue open for a while to collect input for more people. I'm not sure the rule is a bad one, but you know what they say - "vox populi, vox dei".

[zmoazeni]

@bbatsov I'll weigh in to say I've worked with ruby for a while and have not seen this style before (I'm just one guy though). Didn't even know it existed. And even now, I still prefer "#{@var}" to "@var". Do you have any links to any well known projects where this is acceptable?

[gaffneyc]

@bbatsov Do you know of any open source projects that use the style? I've been working with ruby for eight years and I've seen it extremely rarely.

[ethicalhack3r]

We use it a little in WPScan but probably only because we saw it on here.

https://github.com/wpscanteam/wpscan/blob/master/lib/wpscan/wp_item.rb

[betamatt]

I wasn't even aware of #@var. Now that I am, I would still question why it's an advantage to have interpolation not be #{explicit}.

[bbatsov]

@gaffneyc To be honest, I don't recall seeing much instance variable interpolation while perusing the source code of other projects. At any rate, I'm seriously considering reversing the rule at this point in the name of clarity and consistency.