ANTLR 4 Runtime (Optimized) 4.9.0 · org.antlr.v4.runtime.UnbufferedCharStream

Modifier and Type	Field and Description
protected int	currentCharIndex Absolute character index.
protected char[]	data A moving window buffer of the data being scanned.
protected Reader	input
protected int	lastChar This is the `LA(-1)` character for the current position.
protected int	lastCharBufferStart When `numMarkers > 0`, this is the `LA(-1)` character for the first character in `data`.
protected int	n The number of characters currently in `data`.
public String	name The name or source of this char stream.
protected int	numMarkers Count up with `mark()` and down with `release()`.
protected int	p 0..n-1 index into `data` of next character.

Access	Constructor and Description
public	UnbufferedCharStream() Useful for subclasses that pull char from other than this.input.
public	UnbufferedCharStream(int bufferSize) Useful for subclasses that pull char from other than this.input.
public	UnbufferedCharStream(InputStream input)
public	UnbufferedCharStream(Reader input)
public	UnbufferedCharStream(InputStream input, int bufferSize)
public	UnbufferedCharStream(Reader input, int bufferSize)

Method Summary

Modifier and Type	Method and Description
protected void	add(int c)
public void	consume() Implements org.antlr.v4.runtime.IntStream.consume. Consumes the current symbol in the stream.
protected int	fill(int n) Add `n` characters to the buffer.
protected final int	getBufferStartIndex()
public String	getSourceName() Implements org.antlr.v4.runtime.IntStream.getSourceName. Gets the name of the underlying symbol source.
public String	getText(Interval an interval within the stream interval) Implements org.antlr.v4.runtime.CharStream.getText. This method returns the text for a range of characters within this input stream.
public int	index() Implements org.antlr.v4.runtime.IntStream.index. Return the index into the stream of the input symbol referred to by `LA(1)`.
public int	LA(int i) Implements org.antlr.v4.runtime.IntStream.LA. Gets the value of the symbol at offset `i` from the current position.
public int	mark() Implements org.antlr.v4.runtime.IntStream.mark. Return a marker that we can release later.
protected int	nextChar() Override to provide different source of characters than `input`.
public void	release(int marker) Implements org.antlr.v4.runtime.IntStream.release. Decrement number of markers, resetting buffer if we hit 0.
public void	seek(int The absolute index to seek to. index) Implements org.antlr.v4.runtime.IntStream.seek. Seek to absolute character index, which might not be in the current sliding window.
public int	size() Implements org.antlr.v4.runtime.IntStream.size. Returns the total number of symbols in the stream, including a single EOF symbol.
public boolean	supportsUnicodeCodePoints() Implements org.antlr.v4.runtime.UnicodeCharStream.supportsUnicodeCodePoints. Determines if the current stream supports Unicode code points.
protected void	sync(int want) Make sure we have 'need' elements from current position `p`.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

currentCharIndex	back to summary
protected int currentCharIndex Absolute character index. It's the index of the character about to be read via `LA(1)`. Goes from 0 to the number of characters in the entire stream, although the stream size is unknown before the end is reached.

data	back to summary
protected char[] data A moving window buffer of the data being scanned. While there's a marker, we keep adding to buffer. Otherwise, `consume()` resets so we start filling at index 0 again.

input	back to summary
protected Reader input

lastChar	back to summary
protected int lastChar This is the `LA(-1)` character for the current position.

lastCharBufferStart	back to summary
protected int lastCharBufferStart When `numMarkers > 0`, this is the `LA(-1)` character for the first character in `data`. Otherwise, this is unspecified.

n back to summary

n	back to summary
protected int n The number of characters currently in `data`. This is not the buffer capacity, that's `data.length`.

protected int n

The number of characters currently in data.

This is not the buffer capacity, that's data.length.

name	back to summary
public String name The name or source of this char stream.

numMarkers	back to summary
protected int numMarkers Count up with `mark()` and down with `release()`. When we `release()` the last mark, `numMarkers` reaches 0 and we reset the buffer. Copy `data[p]..data[n-1]` to `data[0]..data[(n-1)-p]`.

p back to summary

p	back to summary
protected int p 0..n-1 index into `data` of next character. The `LA(1)` character is `data[p]`. If `p == n`, we are out of buffered characters.

protected int p

0..n-1 index into data of next character.

The LA(1) character is data[p]. If p == n, we are out of buffered characters.

Constructor Detail

UnbufferedCharStream	back to summary
public UnbufferedCharStream() Useful for subclasses that pull char from other than this.input.

UnbufferedCharStream	back to summary
public UnbufferedCharStream(int bufferSize) Useful for subclasses that pull char from other than this.input.

UnbufferedCharStream	back to summary
public UnbufferedCharStream(InputStream input)

UnbufferedCharStream	back to summary
public UnbufferedCharStream(Reader input)

UnbufferedCharStream	back to summary
public UnbufferedCharStream(InputStream input, int bufferSize)

UnbufferedCharStream	back to summary
public UnbufferedCharStream(Reader input, int bufferSize)

Method Detail

add	back to summary
protected void add(int c)

consume back to summary

consume	back to summary
public void consume() Implements org.antlr.v4.runtime.IntStream.consume. Doc from org.antlr.v4.runtime.IntStream.consume. Consumes the current symbol in the stream. This method has the following effects: Forward movement: The value of `index()` before calling this method is less than the value of `index()` after calling this method. Ordered lookahead: The value of `LA(1)` before calling this method becomes the value of `LA(-1)` after calling this method. Note that calling this method does not guarantee that `index()` is incremented by exactly 1, as that would preclude the ability to implement filtering streams (e.g. `CommonTokenStream` which distinguishes between "on-channel" and "off-channel" tokens). Annotations @Override

public void consume()

Implements org.antlr.v4.runtime.IntStream.consume.

Doc from org.antlr.v4.runtime.IntStream.consume.

Consumes the current symbol in the stream. This method has the following effects:

Forward movement: The value of index() before calling this method is less than the value of index() after calling this method.
Ordered lookahead: The value of LA(1) before calling this method becomes the value of LA(-1) after calling this method.

Note that calling this method does not guarantee that index() is incremented by exactly 1, as that would preclude the ability to implement filtering streams (e.g. CommonTokenStream which distinguishes between "on-channel" and "off-channel" tokens).

Annotations

@Override

fill	back to summary
protected int fill(int n) Add `n` characters to the buffer. Returns the number of characters actually added to the buffer. If the return value is less than `n`, then EOF was reached before `n` characters could be added.

getBufferStartIndex	back to summary
protected final int getBufferStartIndex()

getSourceName back to summary

getSourceName	back to summary
public String getSourceName() Implements org.antlr.v4.runtime.IntStream.getSourceName. Doc from org.antlr.v4.runtime.IntStream.getSourceName. Gets the name of the underlying symbol source. This method returns a non-null, non-empty string. If such a name is not known, this method returns `UNKNOWN_SOURCE_NAME`. Annotations @Override

public String getSourceName()

Implements org.antlr.v4.runtime.IntStream.getSourceName.

Doc from org.antlr.v4.runtime.IntStream.getSourceName.

Gets the name of the underlying symbol source. This method returns a non-null, non-empty string. If such a name is not known, this method returns UNKNOWN_SOURCE_NAME.

Annotations

@Override

getText back to summary

getText	back to summary
public String getText(Interval interval) Implements org.antlr.v4.runtime.CharStream.getText. Doc from org.antlr.v4.runtime.CharStream.getText. This method returns the text for a range of characters within this input stream. This method is guaranteed to not throw an exception if the specified `interval` lies entirely within a marked range. For more information about marked ranges, see `IntStream#mark`. Parameters interval:Interval an interval within the stream Returns:String the text of the specified interval Annotations @Override

public String getText(Interval interval)

Implements org.antlr.v4.runtime.CharStream.getText.

Doc from org.antlr.v4.runtime.CharStream.getText.

This method returns the text for a range of characters within this input stream. This method is guaranteed to not throw an exception if the specified interval lies entirely within a marked range. For more information about marked ranges, see IntStream#mark.

Parameters

interval:Interval: an interval within the stream

Returns:String

the text of the specified interval

Annotations

@Override

index back to summary

index	back to summary
public int index() Implements org.antlr.v4.runtime.IntStream.index. Doc from org.antlr.v4.runtime.IntStream.index. Return the index into the stream of the input symbol referred to by `LA(1)`. The behavior of this method is unspecified if no call to an `initializing method` has occurred after this stream was constructed. Annotations @Override

public int index()

Implements org.antlr.v4.runtime.IntStream.index.

Doc from org.antlr.v4.runtime.IntStream.index.

Return the index into the stream of the input symbol referred to by LA(1).

The behavior of this method is unspecified if no call to an initializing method has occurred after this stream was constructed.

Annotations

@Override

LA back to summary

LA	back to summary
public int LA(int i) Implements org.antlr.v4.runtime.IntStream.LA. Doc from org.antlr.v4.runtime.IntStream.LA. Gets the value of the symbol at offset `i` from the current position. When `i==1`, this method returns the value of the current symbol in the stream (which is the next symbol to be consumed). When `i==-1`, this method returns the value of the previously read symbol in the stream. It is not valid to call this method with `i==0`, but the specific behavior is unspecified because this method is frequently called from performance-critical code. This method is guaranteed to succeed if any of the following are true: `i>0` `i==-1` and `index()` returns a value greater than the value of `index()` after the stream was constructed and `LA(1)` was called in that order. Specifying the current `index()` relative to the index after the stream was created allows for filtering implementations that do not return every symbol from the underlying source. Specifying the call to `LA(1)` allows for lazily initialized streams. `LA(i)` refers to a symbol consumed within a marked region that has not yet been released. If `i` represents a position at or beyond the end of the stream, this method returns `EOF`. The return value is unspecified if `i<0` and fewer than `-i` calls to `consume()` have occurred from the beginning of the stream before calling this method. Annotations @Override

public int LA(int i)

Implements org.antlr.v4.runtime.IntStream.LA.

Doc from org.antlr.v4.runtime.IntStream.LA.

Gets the value of the symbol at offset i from the current position. When i==1, this method returns the value of the current symbol in the stream (which is the next symbol to be consumed). When i==-1, this method returns the value of the previously read symbol in the stream. It is not valid to call this method with i==0, but the specific behavior is unspecified because this method is frequently called from performance-critical code.

This method is guaranteed to succeed if any of the following are true:

i>0
i==-1 and index() returns a value greater than the value of index() after the stream was constructed and LA(1) was called in that order. Specifying the current index() relative to the index after the stream was created allows for filtering implementations that do not return every symbol from the underlying source. Specifying the call to LA(1) allows for lazily initialized streams.
LA(i) refers to a symbol consumed within a marked region that has not yet been released.

If i represents a position at or beyond the end of the stream, this method returns EOF.

The return value is unspecified if i<0 and fewer than -i calls to consume() have occurred from the beginning of the stream before calling this method.

Annotations

@Override

mark back to summary

mark	back to summary
public int mark() Implements org.antlr.v4.runtime.IntStream.mark. Return a marker that we can release later. The specific marker value used for this class allows for some level of protection against misuse where `seek()` is called on a mark or `release()` is called in the wrong order. Returns:int Doc from org.antlr.v4.runtime.IntStream.mark. An opaque marker which should be passed to `release()` when the marked range is no longer required. Annotations @Override

public int mark()

Implements org.antlr.v4.runtime.IntStream.mark.

Return a marker that we can release later.

The specific marker value used for this class allows for some level of protection against misuse where seek() is called on a mark or release() is called in the wrong order.

Returns:int

Doc from org.antlr.v4.runtime.IntStream.mark.

An opaque marker which should be passed to release() when the marked range is no longer required.

Annotations

@Override

nextChar	back to summary
protected int nextChar() throws IOException Override to provide different source of characters than `input`.

release	back to summary
public void release(int marker) Implements org.antlr.v4.runtime.IntStream.release. Decrement number of markers, resetting buffer if we hit 0. Annotations @Override

release

back to summary

public void release(int marker)

Implements org.antlr.v4.runtime.IntStream.release.

Decrement number of markers, resetting buffer if we hit 0.

Annotations

@Override

seek back to summary

seek	back to summary
public void seek(int index) Implements org.antlr.v4.runtime.IntStream.seek. Seek to absolute character index, which might not be in the current sliding window. Move `p` to `index-bufferStartIndex`. Parameters index:int Doc from org.antlr.v4.runtime.IntStream.seek. The absolute index to seek to. Annotations @Override

public void seek(int index)

Implements org.antlr.v4.runtime.IntStream.seek.

Seek to absolute character index, which might not be in the current sliding window. Move p to index-bufferStartIndex.

Parameters

index:int

Doc from org.antlr.v4.runtime.IntStream.seek.

The absolute index to seek to.

Annotations

@Override

size	back to summary
public int size() Implements org.antlr.v4.runtime.IntStream.size. Doc from org.antlr.v4.runtime.IntStream.size. Returns the total number of symbols in the stream, including a single EOF symbol. Annotations @Override

size

back to summary

public int size()

Implements org.antlr.v4.runtime.IntStream.size.

Doc from org.antlr.v4.runtime.IntStream.size.

Returns the total number of symbols in the stream, including a single EOF symbol.

Annotations

@Override

supportsUnicodeCodePoints back to summary

supportsUnicodeCodePoints	back to summary
public boolean supportsUnicodeCodePoints() Implements org.antlr.v4.runtime.UnicodeCharStream.supportsUnicodeCodePoints. Doc from org.antlr.v4.runtime.UnicodeCharStream.supportsUnicodeCodePoints. Determines if the current stream supports Unicode code points. Returns:boolean `true` if the current input stream supports Unicode code points; otherwise, `false` if the current input stream returns UTF-16 code units for code points above U+FFFF. Annotations @Override

public boolean supportsUnicodeCodePoints()

Implements org.antlr.v4.runtime.UnicodeCharStream.supportsUnicodeCodePoints.

Doc from org.antlr.v4.runtime.UnicodeCharStream.supportsUnicodeCodePoints.

Determines if the current stream supports Unicode code points.

Returns:boolean

true if the current input stream supports Unicode code points; otherwise, false if the current input stream returns UTF-16 code units for code points above U+FFFF.

Annotations

@Override

sync	back to summary
protected void sync(int want) Make sure we have 'need' elements from current position `p`. Last valid `p` index is `data.length-1`. `p+need-1` is the char index 'need' elements ahead. If we need 1 element, `(p+1-1)==p` must be less than `data.length`.

public Class UnbufferedCharStream

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail