hash_syntax
In Ruby 1.9, you can write a hash with symbol keys in two ways:
{ :foo => bar }
{ foo: bar }
Some have expressed discontent at this syntax change. Luckily, it's purely syntax sugar: there's no reason other than preference to use one or the other (assuming you are targeting 1.9). That means we can freely convert between them! That's what hash_syntax does: it scans Ruby code and turns the code into all 1.8 syntax or all 1.9 syntax.
Using hash_syntax
To convert a whole project to 1.8 syntax:
hash_syntax --to-18
To convert a whole project to 1.9 syntax:
hash_syntax --to-19
With no arguments, hash_syntax will scan the following paths using Dir[]
and operate on
each matching file:
app/**/*.rb
ext/**/*.rb
features/**/*.rb
lib/**/*.rb
spec/**/*.rb
test/**/*.rb
If you wish to convert individual files, you can name them explicitly:
hash_syntax --to-19 lib/foo.rb
That's all there is to it!
How it works
hash_syntax
uses the object_regex
library
(source) to perform regex searches on the Ruby token
stream of a given file. A Ruby 1.8 symbol hash key which can be converted to 1.9's syntax can be described as:
symbeg (ident | kw) sp? hashrocket
By using each token's unique name, (with one tweak: all other operators are op
and the hashrocket is hashrocket
),
object_regex can search using this pattern and find it in the Ruby source. Conveniently, you cannot have a line break
between the symbol and the hashrocket; otherwise, the regex would be a bit more complicated (also needing to consider
comments!). Each match is replaced inline as text, and hash_syntax
notes how much the line has shrunk, in case further
replacements happen on the same line. A better option would be to replace the actual tokens in the stream and reconstruct
the source from the token stream.
Ruby 1.9 symbol tokens are just a single label
token; they are easy to find in the source.
Installation
gem install hash_syntax
Note on Patches/Pull Requests
- Fork the project.
- Make your feature addition or bug fix.
- Add tests for it. This is important so I don't break it in a future version unintentionally.
- Commit, do not mess with rakefile, version, or history. (if you want to have your own version, that is fine but bump version in a commit by itself I can ignore when I pull)
- Send me a pull request. Bonus points for topic branches.
Copyright
Copyright (c) 2011 Michael Edgar. See LICENSE for details.