Better String Library (2015) | Hacker News Reader

Better String Library (2015)

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So we have:

* https://en.wikipedia.org/wiki/String_(computer_science)

* https://en.wikipedia.org/wiki/Rope_(data_structure)

* https://hn.algolia.com/?query=Ropes%2C%20an%20Alternative%20...

* https://en.wikipedia.org/wiki/Piece_table

* https://hn.algolia.com/?query=%22Piece%20Table%22

* https://en.wikipedia.org/wiki/Gap_buffer

* https://hn.algolia.com/?query=Gap%20Buffer

Anything else? Would be nice to implement all of these as a single library!

What am I missing?

This library is called bstrings, but Microsoft has BSTR/BStrings. Those are ucs-2/utf-16, zero terminated, with a length prefix.

In Windows 8, someone at Microsoft decided they had too many string types, so they introduced another one (HSTRING).

In VB/ASP3.0 (Windows 2000) the VB string concat was very slow and I built a small class to just make them concat faster (pre-allocated buffer). Sped up those Response.Write() like 40x.

While writing it I was surprised by all the text vs binary crap Windows does.

I wonder if they used BSTR. Which was made for COM and OLE. Iirc vb and vbscript basically spoke COM.

Each BSTR is on the COM heap, and they have just one length field, no notion of "capacity". So you don't get amortized constant time appends.

The NT kernel had UNICODE_STRING which had a capacity. So many string types...

Wouldn't https://github.com/websnarf/bstrlib be a better URL?

Yes :-)

Not sure why it mentions C++. C++ has std::string which is far superior to this.

That is true. I've used bstring before in my project and it's been at least a magnitude slower that std::string in basic operations (concatenation, replacement(s) and so on.)

Seems like asking for trouble to have the struct not opaque.

I believe this is the same string representation Rust uses? Although in Rust the empty string is guaranteed to not allocate memory, not sure if that's true here.

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