This a ANSI C99 implementation of the HAT-trie data structure of Askitis and Sinha, an extremely efficient (space and time) modern variant of tries.

The version implemented here maps arrays of bytes to words (i.e., unsigned longs), which can be used to store counts, pointers, etc, or not used at all if you simply want to maintain a set of unique strings.

For details see,

1. Askitis, N., & Sinha, R. (2007). HAT-trie: a cache-conscious trie-based data structure for strings. Proceedings of the thirtieth Australasian conference on Computer science-Volume 62 (pp. 97–105). Australian Computer Society, Inc.

2. Askitis, N., & Zobel, J. (2005). Cache-conscious collision resolution in string hash tables. String Processing and Information Retrieval (pp. 91–102). Springer.

git clone [email protected]:dcjones/hat-trie.git
cd hat-trie
autoreconf -i
./configure
make install

To use the library, include hat-trie.h and link using -lhat-trie.

Build and run the tests:

make check

• Ruby - https://github.com/luikore/triez
• Python - https://github.com/kmike/hat-trie