parsii.tokenizer

Class LookaheadReader

java.lang.Object

parsii.tokenizer.Lookahead<Char>

parsii.tokenizer.LookaheadReader

public class LookaheadReader
extends Lookahead<Char>

An efficient reader of character streams, reading character by character and supporting lookaheads.

Helps to read characters from a Reader one after another. Using next, upcoming characters can be inspected without consuming (removing) the current one.

Field Summary

Fields inherited from class parsii.tokenizer.Lookahead

endOfInputIndicator, endReached, itemBuffer, problemCollector

Constructor Summary

Constructors

Constructor and Description
LookaheadReader(Reader input) Creates a new LookaheadReader for the given Reader.

Method Summary

Modifier and Type	Method and Description
protected Char	endOfInput() Creates the end of input indicator item.
protected Char	fetch() Fetches the next item from the stream.
String	toString()

Methods inherited from class parsii.tokenizer.Lookahead

consume, consume, current, getProblemCollector, next, next, setProblemCollector

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

LookaheadReader

public LookaheadReader(Reader input)

Creates a new LookaheadReader for the given Reader.

Internally a BufferedReader is used to efficiently read single characters. The given reader will not be closed by this class.

Parameters:

input - the reader to draw the input from

Method Detail

endOfInput

protected Char endOfInput()

Description copied from class: Lookahead

Creates the end of input indicator item.

This method will be only called once, as the indicator is cached.

Specified by:

endOfInput in class Lookahead<Char>

Returns:

a special item which marks the end of the input

fetch

protected Char fetch()

Description copied from class: Lookahead

Fetches the next item from the stream.

Specified by:

fetch in class Lookahead<Char>

Returns:

the next item in the stream or null to indicate that the end was reached

toString

public String toString()

Overrides:

toString in class Object