The TrieST class represents an symbol table of key-value pairs, with string keys and generic values. It supports the usual Put, Get, Indexer, Contains, Delete, Count, and IsEmpty methods. It also provides character-based methods for finding the string in the symbol table that is the Longest prefix of a given prefix, finding all strings in the symbol table that Start with a given prefix, and finding all strings in the symbol table that Match a given pattern. A symbol table implements the Associative array abstraction: when associating a value with a key that is already in the symbol table, the convention is to replace the old value with the new value. Unlike DictionaryTKey, TValue, this class uses the convention that values cannot be null. Setting the value associated with a key to null is equivalent to deleting the key from the symbol table.

This implementation uses a 256-way trie. The Put, Contains, Delete, and Longest prefix operations take time proportional to the length of the key (in the worst case). Construction takes constant time. The Count, and IsEmpty operations take constant time. Construction takes constant time.