AbstractCharStream (hope-lang 1.0-SNAPSHOT API)

java.lang.Object
- io.appform.hope.lang.parser.AbstractCharStream

All Implemented Interfaces:

CharStream

Direct Known Subclasses:

JavaCharStream
```
public abstract class AbstractCharStream
extends Object
implements CharStream
```
An implementation of interface CharStream, where the stream is assumed to contain only ASCII characters (without unicode processing).

Field Summary

Fields
Modifier and Type	Field and Description
`protected int`	`available`
`protected int[]`	`bufcolumn`
`protected char[]`	`buffer`
`protected int[]`	`bufline`
`protected int`	`bufpos` Position in buffer.
`protected int`	`bufsize`
`protected int`	`column`
`static int`	`DEFAULT_BUF_SIZE`
`protected int`	`inBuf`
`protected int`	`line`
`protected int`	`maxNextCharInd`
`protected char[]`	`nextCharBuf`
`protected int`	`nextCharInd`
`protected boolean`	`prevCharIsCR`
`protected boolean`	`prevCharIsLF`
`protected int`	`tokenBegin`

Constructor Summary

Constructors
Constructor and Description

AbstractCharStream(int startline, int startcolumn, int buffersize)
Constructor.

Constructors
Constructor and Description
`AbstractCharStream(int startline, int startcolumn, int buffersize)` Constructor.

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`adjustBeginLineColumn(int nNewLine, int newCol)` Method to adjust line and column numbers for the start of a token.
`void`	`backup(int amount)` Backs up the input stream by amount steps.
`char`	`beginToken()`
`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.
`protected void`	`expandBuff(boolean wrapAround)`
`protected void`	`fillBuff()`
`int`	`getBeginColumn()`
`int`	`getBeginLine()`
`int`	`getEndColumn()`
`int`	`getEndLine()`
`String`	`getImage()`
`char[]`	`getSuffix(int len)`
`int`	`getTabSize()`
`boolean`	`isTrackLineColumn()`
`char`	`readChar()` Read a character.
`void`	`reInit(int startline, int startcolumn, int buffersize)` Reinitialise.
`void`	`setTabSize(int i)` Set the tab size to use.
`void`	`setTrackLineColumn(boolean tlc)` Enable or disable line number and column number tracking.
`protected abstract void`	`streamClose()`
`protected abstract int`	`streamRead(char[] buf, int offset, int len)`
`protected void`	`updateLineColumn(char c)`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - DEFAULT_BUF_SIZE
```
public static final int DEFAULT_BUF_SIZE
```
    See Also:
    
    Constant Field Values
  - bufpos
```
protected int bufpos
```
    Position in buffer.
  - bufsize
```
protected int bufsize
```
  - available
```
protected int available
```
  - tokenBegin
```
protected int tokenBegin
```
  - bufline
```
protected int[] bufline
```
  - bufcolumn
```
protected int[] bufcolumn
```
  - column
```
protected int column
```
  - line
```
protected int line
```
  - prevCharIsCR
```
protected boolean prevCharIsCR
```
  - prevCharIsLF
```
protected boolean prevCharIsLF
```
  - buffer
```
protected char[] buffer
```
  - maxNextCharInd
```
protected int maxNextCharInd
```
  - inBuf
```
protected int inBuf
```
  - nextCharBuf
```
protected char[] nextCharBuf
```
  - nextCharInd
```
protected int nextCharInd
```
- Constructor Detail
  - AbstractCharStream
```
public AbstractCharStream(int startline,
                          int startcolumn,
                          int buffersize)
```
    Constructor.
- Method Detail
  - setTabSize
```
public void setTabSize(int i)
```
    Description copied from interface: CharStream
    
    Set the tab size to use.
    
    Specified by:
    
    setTabSize in interface CharStream
    
    Parameters:
    
    i - spaces per tab
  - getTabSize
```
public int getTabSize()
```
    Specified by:
    
    getTabSize in interface CharStream
    
    Returns:
    
    Current tab size.
  - expandBuff
```
protected void expandBuff(boolean wrapAround)
```
  - streamRead
```
protected abstract int streamRead(char[] buf,
                                  int offset,
                                  int len)
                           throws IOException
```
    Throws:
    
    IOException
  - streamClose
```
protected abstract void streamClose()
                             throws IOException
```
    Throws:
    
    IOException
  - fillBuff
```
protected void fillBuff()
                 throws IOException
```
    Throws:
    
    IOException
  - beginToken
```
public char beginToken()
                throws IOException
```
    Specified by:
    
    beginToken in interface CharStream
    
    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.
    
    Throws:
    
    IOException
  - updateLineColumn
```
protected void updateLineColumn(char c)
```
  - readChar
```
public char readChar()
              throws IOException
```
    Read a character.
    
    Specified by:
    
    readChar in interface CharStream
    
    Returns:
    
    the next character from the selected input
    
    Throws:
    
    IOException - on IO error
  - getBeginColumn
```
public int getBeginColumn()
```
    Specified by:
    
    getBeginColumn in interface CharStream
    
    Returns:
    
    the column number of the first character for current token (being matched after the last call to beginToken).
  - getBeginLine
```
public int getBeginLine()
```
    Specified by:
    
    getBeginLine in interface CharStream
    
    Returns:
    
    the line number of the first character for current token (being matched after the last call to BeginToken).
  - getEndColumn
```
public int getEndColumn()
```
    Specified by:
    
    getEndColumn in interface CharStream
    
    Returns:
    
    the column number of the last character for current token (being matched after the last call to BeginToken).
  - getEndLine
```
public int getEndLine()
```
    Specified by:
    
    getEndLine in interface CharStream
    
    Returns:
    
    the line number of the last character for current token (being matched after the last call to BeginToken).
  - backup
```
public void backup(int amount)
```
    Description copied from interface: CharStream
    
    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.
    
    Specified by:
    
    backup in interface CharStream
    
    Parameters:
    
    amount - Number of chars to back up.
  - reInit
```
public void reInit(int startline,
                   int startcolumn,
                   int buffersize)
```
    Reinitialise.
  - getImage
```
public String getImage()
```
    Specified by:
    
    getImage in interface CharStream
    
    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.
  - getSuffix
```
public char[] getSuffix(int len)
```
    Specified by:
    
    getSuffix in interface CharStream
    
    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(); }
  - done
```
public void done()
```
    Description copied from interface: CharStream
    
    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.
    
    Specified by:
    
    done in interface CharStream
  - adjustBeginLineColumn
```
public void adjustBeginLineColumn(int nNewLine,
                                  int newCol)
```
    Method to adjust line and column numbers for the start of a token.
  - setTrackLineColumn
```
public void setTrackLineColumn(boolean tlc)
```
    Description copied from interface: CharStream
    
    Enable or disable line number and column number tracking.
    
    Specified by:
    
    setTrackLineColumn in interface CharStream
    
    Parameters:
    
    tlc - true to track it, false to not do it.
  - isTrackLineColumn
```
public boolean isTrackLineColumn()
```
    Specified by:
    
    isTrackLineColumn in interface CharStream
    
    Returns:
    
    true if line number and column numbers should be tracked.

Class AbstractCharStream

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

DEFAULT_BUF_SIZE

bufpos

bufsize

available

tokenBegin

bufline

bufcolumn

column

line

prevCharIsCR

prevCharIsLF

buffer

maxNextCharInd

inBuf

nextCharBuf

nextCharInd

Constructor Detail

AbstractCharStream

Method Detail

setTabSize

getTabSize

expandBuff

streamRead

streamClose

fillBuff

beginToken

updateLineColumn

readChar

getBeginColumn

getBeginLine

getEndColumn

getEndLine

backup

reInit

getImage

getSuffix

done

adjustBeginLineColumn

setTrackLineColumn

isTrackLineColumn