PrefixAutomaton

Namespace

Rowles.LeanLucene.Codecs.Fst

Assembly

Rowles.LeanLucene.dll

Accepts any byte sequence that starts with a given UTF-8 prefix. States: 0..prefix.Length-1 = matching prefix bytes, prefix.Length = accepted (sink).

public sealed class PrefixAutomaton : IAutomaton

PrefixAutomaton

Implements

IAutomaton

PrefixAutomaton(ReadOnlySpan<byte>)

Initialises a new PrefixAutomaton from a raw UTF-8 byte prefix.

PrefixAutomaton(string)

Initialises a new PrefixAutomaton from a string prefix, converted to UTF-8.

Start

Initial state of the automaton.

CanMatch(int)

Returns true if the automaton could potentially accept any string starting from the given state. Used for early pruning during intersection. Returns false only if the state is dead (no path to any accept state).

IsAccept(int)

Returns true if the given state is an accepting state.

Step(int, byte)

Transition function: returns next state given current state and input byte, or -1 if no transition.