rope is still under early development. Check it out if you wish to follow my progress or help, but do not use it in your applications (yet!).
rope is a pure Ruby implementation of the Rope data structure.
For many applications, the Rope class can be a drop-in replacement for String that is optimized for certain use cases.
Using a Rope instance over a String may be desirable in applications that manipulate large amounts of text.
rope currently offers:
- Fast string concatenation and substring operations involving large strings
- Immutability, which is desirable for functional programming techniques or multithreaded applications
Planned features for rope:
- Ability to view a function producing characters as a Rope (including I/O operations). For instance, a piece of a Rope may be a 100MB file, but is only read when that section of the string is examined. Concatenating to the end of that Rope does not involve reading the entire file.
- Implement a Rope counterpart to every immutable method available on the String class.
Disadvantages of rope:
- Single character replacements are expensive
- Iterating character-by-character is slightly more expensive than in a String (TODO: how much? .. haven’t implemented iterators yet)
rope is hosted on rubygems
gem install rope
… or in your Gemfile
rope is tested against MRI 1.8.7 and 1.9.2.
Creating a Rope
rope = "123456789".to_rope # Rope::Rope.new("123456789") also works puts rope # "123456789"
A Rope instance can be concatenated with another Rope or String instance.
rope = "12345" string = "6789" rope += string puts rope # "123456789"
A Rope instance offers efficient substring operations. The slice and  methods are synonymous with their String counterparts.
rope = "123456789".to_rope puts rope.slice(3, 4) # 4567 puts rope.slice(-6, 4) # 4567 # TODO: More examples when they are implemented