PerCederberg.Grammatica.Runtime
Class TokenStringDFA

System.Object
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   +--TokenStringDFA

internal class TokenStringDFA

extends System.Object

A deterministic finite state automaton for matching exact strings. It uses a sorted binary tree representation of the state transitions in order to enable quick matches with a minimal memory footprint. It only supports a single character transition between states, but may be run in an all case-insensitive mode.

Since:

1.5

TokenStringDFA

public TokenStringDFA();

Creates a new empty string automaton.

AddMatch

public void AddMatch( string str, bool caseInsensitive, TokenPattern value );

Adds a string match to this automaton. New states and transitions will be added to extend this automaton to support the specified string.

Parameters:

str - the string to match

caseInsensitive - the case-insensitive flag

value - the match value

Match

public TokenPattern Match( ReaderBuffer buffer, bool caseInsensitive );

Checks if the automaton matches an input stream. The matching will be performed from a specified position. This method will not read any characters from the stream, just peek ahead. The comparison can be done either in case-sensitive or case-insensitive mode.

Parameters:

input - the input stream to check

pos - the starting position

caseInsensitive - the case-insensitive flag

Returns:

the match value, or null if no match was found

Throws:

IOException - if an I/O error occurred

ToString

public override string ToString();

Returns a detailed string representation of this automaton.

Returns:

a detailed string representation of this automaton