Can ik make this more beautifull?

Ruby
1

nowadays i try to improve my coding style to produce nicer and beter
readable code. I try to improve the following code but i dont know how.

if condtion1
x=1
else
if condition2
x=2
else
if condition3
x=3
end
end
x=nill
end

there are three different conditions which can not occur at the same
time
can i make this nicer?

2

Actually, when you set x to nil, in the end of the code, you’re losing
your entire second “if” clause. Unless these conditions are calls to
other functions or something like that, you could refactor your code
this way:

x = condition1 ? 1 : nil

Best regards!

Felipe Giotto :wink:

3

On Thu, 2008-01-31 at 20:52 +0900, Remco Hh wrote:

       x=3
    end
  end
  x=nill

end

there are three different conditions which can not occur at the same
time
can i make this nicer?

http://www.ruby-doc.org/docs/ProgrammingRuby/html/tut_expressions.html#S5

HTH,

Felix

4

Jari W. wrote:

     if condition3

A case expression is probably the most clear alternative. The shortest
is perhaps something like:

x = condition1 ? 1 : condition2 ? 2 : 3

Best regards,

Jari W.

Short it may be but this sort of code can hardly be called beautiful, I
have had to maintain crap like this before and the few keystrokes the
author saved was made up for 1000 times when someone updated it and
things didn’t ‘quite’ work how they thought. Ruby allows simplicity and
clarity, this however is heading into obfuscation.

The better solution is to use the elsif keyword to flatten the
indentation:

if (temp == ‘cat’)
x = 1
elsif(temp == ‘dog’)
x = 2
elsif(temp == ‘banana’)
x = 3
else
x = nil
end

5

Remco Hh wrote:

       x=3
    end
  end
  x=nill

end

there are three different conditions which can not occur at the same
time
can i make this nicer?

A case expression is probably the most clear alternative. The shortest
is perhaps something like:

x = condition1 ? 1 : condition2 ? 2 : 3

Best regards,

Jari W.

6

That is apparently a matter of opinion.
I find the single line alternative clear, concise and quite beautiful.
It reads just like a sentence for me.

The 9-line alternative is annoyingly verbose and just burns vertical
space.
That style has me paging up and down or reaching for the scroll bar more
often.
Having to do that does not make the code easier to read in my opinion.

– Mike B.

Peter H. wrote:

Jari W. wrote:

     if condition3

A case expression is probably the most clear alternative. The shortest
is perhaps something like:

x = condition1 ? 1 : condition2 ? 2 : 3

Best regards,

Jari W.

Short it may be but this sort of code can hardly be called beautiful, I
have had to maintain crap like this before and the few keystrokes the
author saved was made up for 1000 times when someone updated it and
things didn’t ‘quite’ work how they thought. Ruby allows simplicity and
clarity, this however is heading into obfuscation.

The better solution is to use the elsif keyword to flatten the
indentation:

if (temp == ‘cat’)
x = 1
elsif(temp == ‘dog’)
x = 2
elsif(temp == ‘banana’)
x = 3
else
x = nil
end

7

On Jan 31, 8:47 am, Peter H. [email protected] wrote:

  else

have had to maintain crap like this before and the few keystrokes the
elsif(temp == ‘banana’)
x = 3
else
x = nil
end

Which is analogous to the case statement:

case temp
when ‘cat’: 1
when ‘dog’: 2
when ‘banana’: 3
else nil
end

8

Peter H. wrote:

  else

elsif(temp == ‘dog’)
x = 2
elsif(temp == ‘banana’)
x = 3
else
x = nil
end

But this elsif solution isn’t heading for clarity either, compared to
using a case expression:
x = case temp
when 1 then ‘cat’
when 2 then ‘dog’
when 3 then ‘banana’
else nil
end

In the elsif example, x appears 4 times instead of 1, temp appears 3
times instead of 1. Apart from require an editor that support
refactoring and the risk of typos, there will also be a performance hit
when temp isn’t matched.

Best regards,

Jari W.

9

On Jan 31, 9:14 am, Mike B. [email protected] wrote:

– Mike B.

clarity, this however is heading into obfuscation.
else
x = nil
end

–
Posted viahttp://www.ruby-forum.com/.

Since your making a choice, a hash seems like it might be a tidy
option:

answers = {condition1=>1, condition2=>2, condition3=>3}
x = answers[condition]

As for the oneline version, I always find it particulary confusing in
Ruby as you can have ? at the end of a method or it can be used in
front a character to get the characters ASCII code. And nesting just
multiplies the problemn, IMHO

cheers

10

Jari W. wrote:

times instead of 1. Apart from require an editor that support
refactoring and the risk of typos, there will also be a performance
hit when temp isn’t matched.

Indeed this is a nice solution to the problem of assigning a value.
However the ‘temp == …’ was of my own invention and not part of the
OP. That simply gave ‘condition1’, ‘condition2’ etc so there is a strong
possibility that what you propose would not work for him as the
conditions might not be based upon the same variable as in my example,
if the OP is new to programming you will have led him down the wrong
path by not pointing out that your solution only works for conditions
based upon the conditions all being tests of temp.

Also when posting code it helps to run it, no matter how much of a
genius you are. Your code does not do what mine did. Try this instead:

x = case temp
when ‘cat’ then 1
when ‘dog’ then 2
when ‘banana’ then 3
else nil
end

I would worry less about how many keystrokes you have saved and spend a
little more time getting it right and testing your code. You wrote 3
lines less than me and got it completely backwards.

11

2008/1/31, Jari W. [email protected]:

     x=2

can i make this nicer?

x = 1
x = case temp
when 1 then ‘cat’
when 2 then ‘dog’
when 3 then ‘banana’
else nil
end

In the elsif example, x appears 4 times instead of 1, temp appears 3
times instead of 1. Apart from require an editor that support
refactoring and the risk of typos, there will also be a performance hit
when temp isn’t matched.

If you are using “case” then there is yet another solution:

x = case
when condition1 then 1
when condition2 then 2
when condition3 then 3
else nil
end

Another approach would be to stuff conditions in an array:

CONDITIONS = [
lambda {|x| condition1 },
lambda {|x| condition2 },
lambda {|x| condition3 },
]

def test(*values)
CONDITIONS.each_with_index do |c,i|
return i+1 if c[*values]
end
nil
end

x = test “whatever”

Kind regards

robert

12

On Jan 31, 10:18 am, Peter H. [email protected] wrote:

In the elsif example, x appears 4 times instead of 1, temp appears 3
path by not pointing out that your solution only works for conditions
end

I would worry less about how many keystrokes you have saved and spend a
little more time getting it right and testing your code. You wrote 3
lines less than me and got it completely backwards.

On a more general note, here are some guidelines I use to write clear
code. All of these guidelines follow the principle of lightening the
load on your working memory:

(1) Name variables what you call them. If you have a variable named
a and someone asks, “What’s a?” and you say “That’s the amount of time
left”, then rename a to time_left.
(2) In general, avoid abbreviations. The time you save typing is
wasted in other areas. While it may be completely obvious to you that
“prev” means preview, the comment next to the code that mentions
“previous” values can confuse the issue (yes, this is a real-life
example). Abbreviations also may force the user of your code to have
to look up method names more often (Now was that method called prev or
previous?)
(3) Write cohesively. Ideally, each part of the system should be
responsible for one clearly-expressed thing. Each method should have
one purpose, each class should have one overarching, easily-expressed
purpose, etc.

13

Mike B. wrote:

That is apparently a matter of opinion.
I find the single line alternative clear, concise and quite beautiful.
It reads just like a sentence for me.

The 9-line alternative is annoyingly verbose and just burns vertical
space.
That style has me paging up and down or reaching for the scroll bar more
often.
Having to do that does not make the code easier to read in my opinion.

When you have to debug or maintain multiply nested ?: logic you will
find yourself questioning the parentage of the original programmer. ?:
is useful to keep minor details from getting verbose, nested ?: is the
path to madness.

14

Felipe Giotto ha scritto:

  else
     if condition3
       x=3
    end
  end
  x=nill

end

there are three different conditions which can not occur at the same
time
can i make this nicer?

just learn to quote… http://www.carnackyweb.com/?p=30

15

Mike B. ha scritto:

– Mike B.

x = nil
end

quoting…this stranger!! http://www.carnackyweb.com/?p=30

16

Hi,

Am Donnerstag, 31. Jan 2008, 22:47:22 +0900 schrieb Peter H.:

Jari W. wrote:
if (temp == ‘cat’)
x = 1
elsif(temp == ‘dog’)
x = 2
elsif(temp == ‘banana’)
x = 3
else
x = nil
end

x = if cond1 then
1
elsif cond2 then
2
elsif cond3 then
3
end

The else clause is superfluous.

Bertram

17

Peter H. wrote:

Mike B. wrote:

That is apparently a matter of opinion.
I find the single line alternative clear, concise and quite beautiful.
It reads just like a sentence for me.
…

When you have to debug or maintain multiply nested ?: logic you will
find yourself questioning the parentage of the original programmer. ?:
is useful to keep minor details from getting verbose, nested ?: is the
path to madness.

Well you might, but I won’t. Like I said, it’s a matter of opinion.
I don’t have problem with nested ?:
I usually use brackets with them. For me that’s works as well
as indentation and verticality.

– Mike