Re^2: Ternary operators: a hinderance, not a help

in reply to Re: Ternary operators: a hinderance, not a help
in thread Ternary operators: a hinderance, not a help

Agreed, for that example.

As I state in the OP, however, my point about readability and clarity is concerned more with more complex constructs, of which that example is not one :)

Vertical space savings are all well and good, but not at the expense of readability. Chained/cascading ternaries quickly lose readability, especially when combined with other code elements.

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Comment on Re^2: Ternary operators: a hinderance, not a help

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Re^3: Ternary operators: a hinderance, not a help by fizbin (Chaplain) on Aug 09, 2005 at 20:55 UTC
I think that what you may be missing is that vertical space savings often enhance readability in terms of making it possible to see the whole forest at once. In the same vein, I've seen (mostly beginning C++) people say that printf-formatted strings are too much like line noise, and everything should really be formatted through the expressive cout format, with operators to change the number of digits of precision, etc. The same people might well complain about `pack`. The common lisp community often fields complaints about how terribly obscure the syntax is to `format`. The point is that compressing stuff that's not terribly important to understanding the whole improves understanding of the code overall. Good code should read like stuff you want to read, and my eyes glaze over with too much pointless verbosity. (Usually, my eyes glazing is a sign that the code I'm reading suffers from severe cut-and-paste and really needs to be refactored to deal with multiple cases in a more generic fashion.) You've obviously encountered several bad uses of the ?: operator. Allow me to present at least one good one: `my $numspells = ($doDeanStuff ? 1 : 0) + ($doSeamusStuff ? 1 : 0) + ($doHarryStuff ? 2 : 0) # Harry's stuff takes multipl +e spells + ($doRonStuff ? 1 : 0) + ($doSeverusStuff ? 5 : 0); # it's really complicated print "Budget for this incantation is $numspells spells\n";` [download] Now in this case I'm sure you could do: `my $numspells = 0; $numspells += 1 if ($doDeanStuff); $numspells += 1 if ($doSeamusStuff); $numspells += 2 if ($doHarryStuff); # Harry's stuff takes multiple sp +ells $numspells += 1 if ($doRonStuff); $numspells += 5 if ($doSeverusStuff); # it's really complicated` [download] But I think that the first version is easier - or at least, faster - to read. (more whitespace per bit of meaning) And code that's faster to read is more likely to get read in full before someone makes changes to it. (Yeah, I'm just getting around to reading book 6 now) `-- @/=map{[/./g]}qw/.h_nJ Xapou cets krht ele_ r_ra/; map{y/X_/\n /;print}map{pop@$_}@/for@/` [download]	[reply] [d/l] [select]
Re^3: Ternary operators: a hinderance, not a help by Anonymous Monk on Aug 10, 2005 at 10:56 UTC
As I state in the OP, however, my point about readability and clarity is concerned more with more complex constructs, of which that example is not one :) I got the impression the OP condemned all use of `?:`. If your opinion is "use `?:` when that's readable, use `if/then/else` when that is", you and I agree, because that's what I do. I use `?:` when I find that more readable `if/then/else`, otherwise, I use `if/then/else`. Chained/cascading ternaries quickly lose readability, especially when combined with other code elements. So do chained/cascading `if/then/else` constructs. Or nested loops, or nested indices. Your original example, I would write either as: `my $number = $logical_test ? $value : 0;` [download] or `my $number = $value; $number = 0 unless $logical_test;` [download] or `my $number = 0; $number = $value if $logical_test;` [download] depending whether I want to stress the default value of `$number`. (I might use one of the latter two if `$logical_test` is expected to have a particular value, and it not having it is an exception, I use the former line if $logical_test could go both ways). If `$logical_test` is 0 if it's false, I might even write it as: `my $number = $logical_test && $value;` [download] I wouldn't easily write: `my $number; if ($logical_test) { $number = $value; } else { $number = 0; }` [download] as it assigns an initial value to `$number` in a different scope than its declaration - IMO, that doesn't score bonus points when it comes to readability. It's also 7 lines instead of 1, although it can easily be shortened to: `my $number; if ($logical_test) {$number = $value} else {$number = 0}` [download] But still, it's three lines. And worse, both blocks have two thirds of their tokens in common - which just shouts "factor out, factor out". Which would lead to: `my $number = do {if ($logical_test) {$value} else {0}};` [download] But then I prefer: `my $number = $logical_test ? $value : 0;` [download]	[reply] [d/l] [select]

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