Lucene.Net  3.0.3
Lucene.Net is a .NET port of the Java Lucene Indexing Library
 All Classes Namespaces Files Functions Variables Typedefs Enumerations Properties
Public Member Functions | Properties | List of all members
Lucene.Net.QueryParsers.ICharStream Interface Reference

This interface describes a character stream that maintains line and column number positions of the characters. It also has the capability to backup the stream to some extent. An implementation of this interface is used in the TokenManager implementation generated by JavaCCParser. More...

Inherited by Lucene.Net.QueryParsers.FastCharStream.

Public Member Functions

char ReadChar ()
 Returns the next character from the selected input. The method of selecting the input is the responsibility of the class implementing this interface. Can throw any java.io.IOException.
 
void Backup (int amount)
 Backs up the input stream by amount steps. Lexer calls this method if it had already read some characters, but could not use them to match a (longer) token. So, they will be used again as the prefix of the next token and it is the implemetation's responsibility to do this right.
 
char BeginToken ()
 Returns the next character that marks the beginning of the next token. All characters must remain in the buffer between two successive calls to this method to implement backup correctly.
 
char[] GetSuffix (int len)
 Returns an array of characters that make up the suffix of length 'len' for the currently matched token. This is used to build up the matched string for use in actions in the case of MORE. A simple and inefficient implementation of this is as follows :
 
void Done ()
 The lexer calls this function to indicate that it is done with the stream and hence implementations can free any resources held by this class. Again, the body of this function can be just empty and it will not affect the lexer's operation.
 

Properties

int Column [get]
 Returns the column position of the character last read.
 
int Line [get]
 Returns the line number of the character last read.
 
int EndColumn [get]
 Returns the column number of the last character for current token (being matched after the last call to BeginTOken).
 
int EndLine [get]
 Returns the line number of the last character for current token (being matched after the last call to BeginTOken).
 
int BeginColumn [get]
 Returns the column number of the first character for current token (being matched after the last call to BeginTOken).
 
int BeginLine [get]
 Returns the line number of the first character for current token (being matched after the last call to BeginTOken).
 
string Image [get]
 Returns a string made up of characters from the marked token beginning to the current buffer position. Implementations have the choice of returning anything that they want to. For example, for efficiency, one might decide to just return null, which is a valid implementation.
 

Detailed Description

This interface describes a character stream that maintains line and column number positions of the characters. It also has the capability to backup the stream to some extent. An implementation of this interface is used in the TokenManager implementation generated by JavaCCParser.

All the methods except backup can be implemented in any fashion. backup needs to be implemented correctly for the correct operation of the lexer. Rest of the methods are all used to get information like line number, column number and the String that constitutes a token and are not used by the lexer. Hence their implementation won't affect the generated lexer's operation.

Definition at line 40 of file CharStream.cs.

Member Function Documentation

void Lucene.Net.QueryParsers.ICharStream.Backup ( int  amount)

Backs up the input stream by amount steps. Lexer calls this method if it had already read some characters, but could not use them to match a (longer) token. So, they will be used again as the prefix of the next token and it is the implemetation's responsibility to do this right.

Implemented in Lucene.Net.QueryParsers.FastCharStream.

char Lucene.Net.QueryParsers.ICharStream.BeginToken ( )

Returns the next character that marks the beginning of the next token. All characters must remain in the buffer between two successive calls to this method to implement backup correctly.

Implemented in Lucene.Net.QueryParsers.FastCharStream.

void Lucene.Net.QueryParsers.ICharStream.Done ( )

The lexer calls this function to indicate that it is done with the stream and hence implementations can free any resources held by this class. Again, the body of this function can be just empty and it will not affect the lexer's operation.

Implemented in Lucene.Net.QueryParsers.FastCharStream.

char [] Lucene.Net.QueryParsers.ICharStream.GetSuffix ( int  len)

Returns an array of characters that make up the suffix of length 'len' for the currently matched token. This is used to build up the matched string for use in actions in the case of MORE. A simple and inefficient implementation of this is as follows :

{ String t = GetImage(); return t.substring(t.length() - len, t.length()).toCharArray(); }

Implemented in Lucene.Net.QueryParsers.FastCharStream.

char Lucene.Net.QueryParsers.ICharStream.ReadChar ( )

Returns the next character from the selected input. The method of selecting the input is the responsibility of the class implementing this interface. Can throw any java.io.IOException.

Implemented in Lucene.Net.QueryParsers.FastCharStream.

Property Documentation

int Lucene.Net.QueryParsers.ICharStream.BeginColumn
get

Returns the column number of the first character for current token (being matched after the last call to BeginTOken).

Definition at line 77 of file CharStream.cs.

int Lucene.Net.QueryParsers.ICharStream.BeginLine
get

Returns the line number of the first character for current token (being matched after the last call to BeginTOken).

Definition at line 82 of file CharStream.cs.

int Lucene.Net.QueryParsers.ICharStream.Column
get

Returns the column position of the character last read.

<deprecated> </deprecated>

See Also
EndColumn

Definition at line 54 of file CharStream.cs.

int Lucene.Net.QueryParsers.ICharStream.EndColumn
get

Returns the column number of the last character for current token (being matched after the last call to BeginTOken).

Definition at line 67 of file CharStream.cs.

int Lucene.Net.QueryParsers.ICharStream.EndLine
get

Returns the line number of the last character for current token (being matched after the last call to BeginTOken).

Definition at line 72 of file CharStream.cs.

string Lucene.Net.QueryParsers.ICharStream.Image
get

Returns a string made up of characters from the marked token beginning to the current buffer position. Implementations have the choice of returning anything that they want to. For example, for efficiency, one might decide to just return null, which is a valid implementation.

Definition at line 102 of file CharStream.cs.

int Lucene.Net.QueryParsers.ICharStream.Line
get

Returns the line number of the character last read.

<deprecated> </deprecated>

See Also
EndLine

Definition at line 62 of file CharStream.cs.


The documentation for this interface was generated from the following file: