5 ms·
> Braces Are Free, Use Them I disagree. Braces have a cognitive load, particularly if they're given whole lines to themselves. Which is easier to read, whil
by adavies42 15y ago
> Braces Are Free, Use Them
I disagree. Braces have a cognitive load, particularly if they're given whole lines to themselves. Which is easier to read,
while ((len = getline(line, MAXLINE)) > 0)
if (len > max) {
max = len;
copy(longest, line);
}
if (max > 0) /* there was a line */
printf("%s", longest);
or
while ((len = getline(line, MAXLINE)) > 0)
{
if (len > max)
{
max = len;
copy(longest, line);
}
}
if (max > 0) /* there was a line */
{
printf("%s", longest);
}
? Personally, I'd probably write it
while ((len = getline(line, MAXLINE)) > 0)
if (len > max) {
max = len;
copy(longest, line);
}
if (max > 0) printf("%s", longest);
. Consistent structural indenting makes it easy to see the boundaries of the control structures.
- SeanLuke 15y agoI'm probably the last person in the world to prefer: while ((len = getline(line, MAXLINE)) > 0) if (len > max) { max = len; copy(longest, line); } if (max > 0) /* there was a line */ printf("%s", longest); I fear this may be literally true: this brace style is called Whitesmith's, and I was reporting bugs to the cc-mode indenter for emacs a while ago. BSD/Allman and K&R styles never made sense to me.
- glitch 15y agoSeanLuke, that is exactly how I'd write it too! ✼Whitesmith fistbump✼ — Related: I love the Wikipedia talk section on it: http://en.wikipedia.org/wiki/Talk:Indent_style#Whitesmiths_style http://en.wikipedia.org/wiki/Talk:Indent_style#Whitesmiths_s...
- Roboprog 15y agoSteve McConnell makes a pretty good case for Whitesmith's formatting in this book (at least the first edition) in the code formatting chapter: http://books.google.com/books/about/Code_complete.html?id=QnghAQAAIAAJ http://books.google.com/books/about/Code_complete.html?id=Qn... Of course, he presents most of the major styles, pretending to be "fair and balanced", but if you read between the lines of the "abstract block" argument, it's clear that the other styles which align keywords or grouping symbols at a different level other than the compound statements they delimit are brain damaged, or at least visually misleading.
- zedshaw 15y agoAdd a new statement to the while-loop. Now you've figured out why that style isn't so hot. You now have to remember to go add the new braces, and typically people are mentally putting them in so they forget. Same with the last if-statement. You'll go, add the new line, indent and go "cool done". Then scratch your head for hours wondering why it's not working.
- Roboprog 15y agoExactly. Fully bracketed syntax prevents this kind of maintenance breakage. Weird contrast: Perl, for all its klugy syntax, requires fully bracketed syntax on the statement bodies of "if", "while" & the like, so this never happens. Of course, you get other readability issues there...
- SeanLuke 15y agoOh, well there are two issues here: whether to always include braces, and what brace style to use. Whitesmiths is a brace style, that's what I was pointing out. The decision to include braces or not is a different thing. I tend to omit braces in obvious situations, but am not beholden to it.
- NickPollard 15y agoI'm currently experimenting with a hybrid of this and K&R style, that would look like this: while ((len = getline(line, MAXLINE)) > 0) if (len > max) { max = len; copy(longest, line); } if (max > 0) /* there was a line */ printf("%s", longest); So far I'm finding that it gives good readability, doesn't waste too many lines on braces, and doesn't run into many issues of accidentally leaving braces out. I started it after having started writing lisp and python, and I'm getting used to just ignoring the braces and going by indentation, which this style emphasises.
- ufo 15y agoWe are talking abou K&R here. Please use the less spacious TrueBraceStyle instead of the heretic Allman style. :) Joke aside, the problem I see in your argument is that lack of braces is also a cognitive load. If braces are always there I can safely ignore them but if they can be ommited I need to worry if a certain piece if code is braced or not when I read and edit it. The only exception I currently live with is single line if statements, as long as the statement is on the same line as the `if`
- lurker14 15y agoThe middle version uses braces nicely to add whitespace to the function to help the reader flow through the code, instead of chasing matched-parens and wondering if each line is a continuation of the previous.
- scott_s 15y agoBecause it's the style I use, and because I don't need to bug-check the indented code to make sure it's braced correctly, I find this easiest to read: while ((len = getline(line, MAXLINE)) > 0) { if (len > max) { max = len; copy(longest, line); } } if (max > 0) { /* there was a line */ printf("%s", longest); }
- silon3 15y agoBy far.
- cbs 15y agoEasiest to read? The middle. The way I would write it for my own use is closest to the top, but the easiest to read is the middle. Always using braces, and giving them their own lines makes nesting as unambiguous as possible and the extra white space reduces density making foreign code easier to digest.
- nessus42 15y agoAll this talk about where the right place to put braces is, makes me pine for Python.
- deleted 15y ago[deleted]
- deleted 15y ago[deleted]
- deleted 15y ago[deleted]
- anon_d 15y agoI would write it as follows. Same argument. while ((len=getline(line,MAXLINE)) > 0) if (len>max) max=len, copy(longest,line); if (max > 0) printf("%s",longest);
- zedshaw 15y ago> Braces have a cognitive load, particularly if they're given whole lines to themselves. Which is easier to read, Checking braces has a higher load when they aren't there and when they aren't consistently used. But, without evidence both of our points are pointless. So, in my book I'm pushing the standards of always use braces except in a few little cases.
- mindcrime 15y agoI'll take the 2nd one, please. And twice on Sunday.
- Teckla 15y agoWhen it comes to assignment and comparison in constructs such as while loops, I think this variation adds readability: while (len = getline(line, MAXLINE), len > 0) ... I've never seen anyone else use it, though.