Generates Ctags and Vim Paths from Gemfile.lock

ctags_vim_paths_gemfile.rb

#!/usr/bin/ruby
require 'rubygems'
require 'bundler'

=begin
This script was written to incorporate Bundler and Gemfile.lock into
Vim's tag and file-finding tools.
=end

# This code generates ctags.  If a Gemfile.lock is found
# in the current directory, tags will be generated for
# every gem referenced in the Gemfile.

bundler_paths = []
if File.exist?('Gemfile.lock')
  lockfile_contents = Bundler.read_file('Gemfile.lock')
  lockfile = Bundler::LockfileParser.new(lockfile_contents)
  bundler_paths = lockfile.specs.map do |spec|
    spec.__materialize__
    spec.full_gem_path
  end
end

tags_file    = ".tags"
opts         = "--extra=+f -R -f #{tags_file}"
exclude_dirs = "--exclude=.git --exclude=log --exclude=.svn"
ctag_paths   = "* #{bundler_paths.map {|x| x + '/*'}.join(' ')}"
command      = "ctags #{opts} #{exclude_dirs} #{ctag_paths} 2> /dev/null"

puts "Processing ctags..."
system command
puts "Wrote ctags to '#{tags_file}'"

# This code generates a script that loads Bundler paths into vim.
# To use this script in vim, put this command into your .vimrc:
#
# autocmd BufNewFile,BufRead *.rb silent! source .paths.vim<cr>

system "rm -f .paths.vim"
unless bundler_paths.empty?
  gem_paths  = Gem.all_load_paths
  vim_paths  = bundler_paths.map {|x| x = x + '/lib'} - gem_paths
  paths_file = ".paths.vim"
  File.open(paths_file, 'w') do |file|
    vim_paths.each {|x| file.puts "silent! set path+=#{x}" }
  end
  puts "Wrote #{vim_paths.length} vim paths to '#{paths_file}'"
end

Thanks for that explanation.