TextMate Command: Reformat C Defines

For the TextMate users out there who write C and C++, here’s a handy command for beautifying a bunch of #define lines. I don’t know about you, but I’m used to seeing lots of header files with this kind of junk:

#define FOO       1
#define BAR    3
#define BAZ   (FOO + BAR)
#define REALLY_LONG_DEFINE (BAZ * 2)

What I want is a magic command to line up all the definitions to the column that’s the nearest multiple of the tab size, like so:

#define FOO                 1
#define BAR                 3
#define BAZ                 (FOO + BAR)
#define REALLY_LONG_DEFINE  (BAZ * 2)

So here’s a script to do that: Download “Reformat Defines” TextMate Command. Source code follows for the curious.

Source Code

#!/usr/bin/ruby

lines = Array.new

# Read in lines
STDIN.readlines.each do |line|
  match = line.strip.match(/#define (\S+)\s+(.*)/)
  
  if (match)
    lines << { :constant => match[1], :value => match[2] }
  else
    lines << line.rstrip
  end
end

# Find longest constant
constant_size = 0;
lines.each do |line|
  if (line.class == Hash && line[:constant].length > constant_size)
    constant_size = line[:constant].length
  end
end

# Up size to next multiple of the tab size:
tab_size = ENV['TM_TAB_SIZE'].to_i
constant_size = constant_size + (tab_size - (constant_size % tab_size))

#  Format output
lines.each do |line|
  if (line.class == Hash)
    printf("#define %-#{constant_size}s%s\n", line[:constant], line[:value])
  else
    puts line
  end
end