Programming Perl, 4th Edition

Programming with Style

You’ll certainly have your own preferences in regard to formatting, but there are some general guidelines that will make your programs easier to read, understand, and maintain. Larry made some general recommendations in perlstyle, but they are just recommendations. You might also like Perl Best Practices or Modern Perl.

The most important thing is to run your programs under strict and warnings pragmas, unless you have a good reason not to. If you need to turn them off, use no in the smallest scope possible. The sigtrap and even the diagnostics pragmas may also be beneficial.

Regarding aesthetics of code layout, about the only thing Larry cares strongly about is that the closing brace of a multiline BLOCK should be “outdented” to line up with the keyword that started the construct. Beyond that, he has other preferences that aren’t so strong. Examples in this book (should) all follow these coding conventions:

• Use four-column indents.

• Put an opening brace on the same line as its preceding keyword, if possible; otherwise, line them up vertically:

  while ($condition) {        # for short ones, align with keywords
      # do something
  }
  
  # if the condition wraps, line up the braces with each other
  while ($this_condition and $that_condition
         and $this_other_long_condition)
  {
      # do something
  }

• Put space before the opening brace of a multiline BLOCK.

• A short BLOCK may be put on one line, including braces.

• Omit the semicolon in a short, one-line BLOCK.

• Surround most operators with space.

• Surround ...