# Sequence 0.1.0 Released **URL:** \ **Category:** Ruby\ **Created:** [October 7, 2006, 7:39am UTC](https://www.ruby-forum.com/t/sequence-0-1-0-released/71341 "2006-10-07T07:39:41Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![pandemic](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/8491ac/32.png) [@pandemic](https://www.ruby-forum.com/u/pandemic)\ **Post date:** [October 7, 2006, 7:39am UTC](https://www.ruby-forum.com/t/sequence-0-1-0-released/71341/1 "2006-10-07T07:39:41Z")
Sequence version 0.1.0 has been released! [http://rubyforge.org/projects/sequence](http://rubyforge.org/projects/sequence) [http://sequence.rubyforge.org/](http://sequence.rubyforge.org/) Sequence is a wrapper api for accessing data in Strings, Arrays, Files, IOs, and Enumerations. Each sequence encapsulates some data and a current position within it. There are methods for moving the position, reading and writing data(with or without moving the position) forward or backward from the current position (or anywhere at all), scanning for patterns (like StringScanner, but it works in Files too, among others), and saving a position that will remain valid even after data is deleted or inserted elsewhere within the sequence. There are also some utility classes for making sequences reversed or circular, turning one-way sequences into two-way, buffering, and making sequences that are subsets or aggregations of existing sequences. Sequence is based on Eric M.'s Cursor library. I’d like to thank Eric for Cursor, without which Sequence would not have existed; my design is very much a derivative of his. known problems: Some unit tests fail Buffered does not work at all Shifting’s modify methods don’t work reliably Some write operations failing for List No unit tests at all for array-like sequences (tho Reg’s unit test does test OfArray at least somewhat…) ---
**Author:** ![pandemic](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/8491ac/32.png) [@pandemic](https://www.ruby-forum.com/u/pandemic)\ **Post date:** [October 7, 2006, 8:05am UTC](https://www.ruby-forum.com/t/sequence-0-1-0-released/71341/2 "2006-10-07T08:05:43Z")
Caleb C. wrote: > position (or anywhere at all), scanning for patterns (like > StringScanner, but it works in Files too, among others), and > saving a position that will remain valid even after data is > deleted or inserted elsewhere within the sequence. [snip] Sounds interesting… is it better than Eric M’s Cursor class? Different in some significant way? Hal ---
**Author:** ![pandemic](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/8491ac/32.png) [@pandemic](https://www.ruby-forum.com/u/pandemic)\ **Post date:** [October 7, 2006, 6:48pm UTC](https://www.ruby-forum.com/t/sequence-0-1-0-released/71341/3 "2006-10-07T18:48:26Z")
On 10/6/06, Hal F. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Sounds interesting… is it better than Eric M’s Cursor > class? Different in some significant way? Well, Sequence is faster than Cursor for most things. I haven’t benchmarked, but (eg) #read should be at least 10-100x faster. (Except when reading from a file, which Cursor optimizes fairly well, if I remember.) I think that the support for #scan and friends (from StringScanner) is better in Sequence. Eric will disagree with me on this. Cursor doesn’t have an equivalent to my Sequence::Subseq. Cursor::Linked more or less corresponds to my Sequence::List (except that I never properly understood Cursor::Linked – how to use it, how it works). Those are the biggest differences. The sequence api has otherwise about the same capabilities as its ancestor. I’ve moved everything around to suit my way of thinking, tho, so it isn’t compatible (except for doing very simple things). ---
**Author:** ![pandemic](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/8491ac/32.png) [@pandemic](https://www.ruby-forum.com/u/pandemic)\ **Post date:** [October 7, 2006, 8:28pm UTC](https://www.ruby-forum.com/t/sequence-0-1-0-released/71341/4 "2006-10-07T20:28:32Z")
On 10/7/06, Caleb C. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > I think that the support for #scan and friends (from StringScanner) is > for doing very simple things). Sorry I haven’t been working on Cursor lately. I will readily admit that performance isn’t too great on Cursor. I was focusing on functionality first. Unfortunately when I go back and improve performance, I’ll be changing the API slightly. My focus for the year has been on Grammar which now has kick-ass performance (even faster than regexp’s when used in conjunction with Dominick Baton’s ruby2cext). It also has some interesting new features (like handling left recursion in an LL(1) parser). I’ll try to get some of this into CVS soon at least. Because Grammar’s are on par (can be faster) with regexp’s I’ll be removing regexp support from Cursor in the next release. It is just too ugly to support in a clean way - they are too tied to String. Grammar on the other hand can work on anything that looks remotely like a Cursor - usually just #read1next will do. So, maybe it is best that Caleb made an derivative of Cursor since he really wanted regexp support. When I get back to Cursor, I’ll be improving performance quite a bit. I’ve been using C++ lately (which I hate) and will probably be taking some of the STL ideas (i.e. iterators, sequences, algorithms) I’ve learned over to Cursor. I think I’ll make it so that you can #extend some of ruby’s standard objects to look like a Cursor (or just #include in that class to make all of them look like Cursor’s). That should give very good performance.