Lexer

java.lang.Object
- java.io.Reader
- - gnu.text.Lexer

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, java.lang.Readable

Direct Known Subclasses:

Lexer, LispReader, XQParser, XslTranslator
```
public class Lexer
extends java.io.Reader
```
Framework for implementing lexical scanners and parsers.

Field Summary

Fields
Modifier and Type	Field and Description
`protected int`	`nesting`
`protected gnu.kawa.io.InPort`	`port`
`protected boolean`	`tentative`
`char[]`	`tokenBuffer` For building tokens of various kinds.
`int`	`tokenBufferLength` The number of chars of tokenBuffer that are used.

Fields inherited from class java.io.Reader
lock

Constructor Summary

Constructors
Constructor and Description

Lexer(gnu.kawa.io.InPort port)

Lexer(gnu.kawa.io.InPort port, SourceMessages messages)

Constructors
Constructor and Description
`Lexer(gnu.kawa.io.InPort port)`
`Lexer(gnu.kawa.io.InPort port, SourceMessages messages)`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods Deprecated Methods
Modifier and Type	Method and Description
`boolean`	`checkErrors(java.io.PrintWriter out, int max)` Returns true if any error were seen.
`boolean`	`checkNext(char ch)` Check if the next character matches a given character.
`void`	`clearErrors()`
`void`	`close()`
`void`	`eofError(java.lang.String msg)`
`void`	`eofError(java.lang.String message, int startLine, int startColumn)`
`void`	`error(char severity, java.lang.String message)`
`void`	`error(char severity, java.lang.String filename, int line, int column, java.lang.String message)`
`void`	`error(java.lang.String message)`
`void`	`fatal(java.lang.String message)`
`int`	`getColumnNumber()` Return the current (zero-based) column number.
`SourceError`	`getErrors()`
`int`	`getLineNumber()` Get the current line number.
`SourceMessages`	`getMessages()`
`java.lang.String`	`getName()`
`gnu.kawa.io.InPort`	`getPort()`
`boolean`	`isInteractive()`
`boolean`	`isTentative()` True if input may be incomplete or actively edited.
`void`	`mark()` Start tentative parsing.
`int`	`peek()`
`void`	`popNesting(char save)` Exit a nested expression, reversing pushNesting
`char`	`pushNesting(char promptChar)` Enter a nested expression.
`int`	`read()`
`int`	`read(char[] buf, int offset, int length)`
`int`	`readCodePoint()` Read a Unicode character (codepoint) by checking for surrogates.
`boolean`	`readDelimited(java.lang.String delimiter)` Scan until a given delimiter.
`static long`	`readDigits(gnu.kawa.io.InPort port, int radix)`
`static long`	`readDigitsInBuffer(gnu.kawa.io.InPort port, long ival, int radix)` Read digits, up to the first non-digit or the buffer limit
`int`	`readIntDigits()`
`int`	`readOptionalExponent()` Read an optional signed integer.
`int`	`readUnicodeChar()` Deprecated. Use `readCodePoint()`.
`void`	`reset()` Stop tentative parsing.
`boolean`	`seenErrors()`
`void`	`setInteractive(boolean v)`
`void`	`setMessages(SourceMessages messages)`
`void`	`setTentative(boolean v)`
`protected void`	`skip_quick()`
`void`	`skip()`
`void`	`tokenBufferAppend(int ch)` Append one character to tokenBuffer, resizing it if need be.
`java.lang.String`	`tokenBufferString()`
`protected void`	`unread_quick()`
`protected void`	`unread()`
`void`	`unread(int ch)`

Methods inherited from class java.io.Reader
mark, markSupported, read, read, ready, skip

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

Field Detail
- port
```
protected gnu.kawa.io.InPort port
```
- tentative
```
protected boolean tentative
```
- nesting
```
protected int nesting
```
- tokenBuffer
```
public char[] tokenBuffer
```
  For building tokens of various kinds.
- tokenBufferLength
```
public int tokenBufferLength
```
  The number of chars of tokenBuffer that are used.

Constructor Detail

Lexer
```
public Lexer(gnu.kawa.io.InPort port)
```

Lexer

public Lexer(gnu.kawa.io.InPort port,
             SourceMessages messages)

Method Detail
- pushNesting
```
public char pushNesting(char promptChar)
```
  Enter a nested expression. This is used in interactive mode to control whether to continue past end of line, depending on whether the expression is incomplete.
  
  Parameters:
  
  promptChar - Used in prompt string to indicate type of nesting.
  
  Returns:
  
  The previous value of promptChar, to be passed to popNesting.
- popNesting
```
public void popNesting(char save)
```
  Exit a nested expression, reversing pushNesting
  
  Parameters:
  
  save - Saved values return by prior pushNesting
- getPort
```
public final gnu.kawa.io.InPort getPort()
```
- close
```
public void close()
           throws java.io.IOException
```
  Specified by:
  
  close in interface java.io.Closeable
  
  Specified by:
  
  close in interface java.lang.AutoCloseable
  
  Specified by:
  
  close in class java.io.Reader
  
  Throws:
  
  java.io.IOException
- read
```
public int read()
         throws java.io.IOException
```
  Overrides:
  
  read in class java.io.Reader
  
  Throws:
  
  java.io.IOException
- readUnicodeChar
```
@Deprecated
public int readUnicodeChar()
                                throws java.io.IOException
```
  Deprecated. Use readCodePoint().
  
  Read a Unicode character (codepoint) by checking for surrogates.
  
  Throws:
  
  java.io.IOException
- readCodePoint
```
public int readCodePoint()
                  throws java.io.IOException
```
  Read a Unicode character (codepoint) by checking for surrogates.
  
  Throws:
  
  java.io.IOException
- read
```
public int read(char[] buf,
                int offset,
                int length)
         throws java.io.IOException
```
  Specified by:
  
  read in class java.io.Reader
  
  Throws:
  
  java.io.IOException
- unread
```
public void unread(int ch)
            throws java.io.IOException
```
  Throws:
  
  java.io.IOException
- peek
```
public int peek()
         throws java.io.IOException
```
  Throws:
  
  java.io.IOException
- skip
```
public void skip()
          throws java.io.IOException
```
  Throws:
  
  java.io.IOException
- unread
```
protected void unread()
               throws java.io.IOException
```
  Throws:
  
  java.io.IOException
- unread_quick
```
protected void unread_quick()
                     throws java.io.IOException
```
  Throws:
  
  java.io.IOException
- checkNext
```
public boolean checkNext(char ch)
                  throws java.io.IOException
```
  Check if the next character matches a given character.
  
  Parameters:
  
  ch - The character to match against.
  
  Returns:
  
  if the character read matches On a match, the position is advanced following that character.
  
  Throws:
  
  java.io.IOException
- skip_quick
```
protected void skip_quick()
                   throws java.io.IOException
```
  Throws:
  
  java.io.IOException
- getMessages
```
public SourceMessages getMessages()
```
- setMessages
```
public void setMessages(SourceMessages messages)
```
- checkErrors
```
public boolean checkErrors(java.io.PrintWriter out,
                           int max)
```
  Returns true if any error were seen. Prints and clears the errors.
  
  Parameters:
  
  out - where to write the error message to
  
  max - maximum number of messages to print (can be 0)
- getErrors
```
public SourceError getErrors()
```
- seenErrors
```
public boolean seenErrors()
```
- clearErrors
```
public void clearErrors()
```
- error
```
public void error(char severity,
                  java.lang.String filename,
                  int line,
                  int column,
                  java.lang.String message)
```
- error
```
public void error(char severity,
                  java.lang.String message)
```
- error
```
public void error(java.lang.String message)
```
- fatal
```
public void fatal(java.lang.String message)
           throws SyntaxException
```
  Throws:
  
  SyntaxException
- eofError
```
public void eofError(java.lang.String msg)
              throws SyntaxException
```
  Throws:
  
  SyntaxException
- eofError
```
public void eofError(java.lang.String message,
                     int startLine,
                     int startColumn)
              throws SyntaxException
```
  Throws:
  
  SyntaxException
- readOptionalExponent
```
public int readOptionalExponent()
                         throws java.io.IOException
```
  Read an optional signed integer. If there is no integer in the input stream, return 1. For excessively large exponents, return Integer.MIN_VALUE or Integer.MAX_VALUE.
  
  Throws:
  
  java.io.IOException
- readDelimited
```
public boolean readDelimited(java.lang.String delimiter)
                      throws java.io.IOException,
                             SyntaxException
```
  Scan until a given delimiter. On success, text upto the delimiter is in then tokenBuffer (with tokenBufferLength marking its length); the delimiter is not included.
  
  Throws:
  
  java.io.IOException
  
  SyntaxException
- readDigitsInBuffer
```
public static long readDigitsInBuffer(gnu.kawa.io.InPort port,
                                      long ival,
                                      int radix)
```
  Read digits, up to the first non-digit or the buffer limit
  
  Parameters:
  
  ival - previously-seen digits or -2 if no digits seen
  
  Returns:
  
  the digits seen as a non-negative long, or -1 on overflow, or -2 if no digits seen
- readDigits
```
public static long readDigits(gnu.kawa.io.InPort port,
                              int radix)
                       throws java.io.IOException
```
  Throws:
  
  java.io.IOException
- readIntDigits
```
public int readIntDigits()
                  throws java.io.IOException
```
  Throws:
  
  java.io.IOException
- getName
```
public java.lang.String getName()
```
- getLineNumber
```
public int getLineNumber()
```
  Get the current line number. The "first" line is number number 0.
- getColumnNumber
```
public int getColumnNumber()
```
  Return the current (zero-based) column number.
- isInteractive
```
public boolean isInteractive()
```
- setInteractive
```
public void setInteractive(boolean v)
```
- isTentative
```
public boolean isTentative()
```
  True if input may be incomplete or actively edited. Used for command-completion and on-the-fly error checking.
- setTentative
```
public void setTentative(boolean v)
```
- tokenBufferAppend
```
public void tokenBufferAppend(int ch)
```
  Append one character to tokenBuffer, resizing it if need be.
- tokenBufferString
```
public java.lang.String tokenBufferString()
```
- mark
```
public void mark()
          throws java.io.IOException
```
  Start tentative parsing. Must be followed by a reset.
  
  Throws:
  
  java.io.IOException
- reset
```
public void reset()
           throws java.io.IOException
```
  Stop tentative parsing. Return to position where we called mark.
  
  Overrides:
  
  reset in class java.io.Reader
  
  Throws:
  
  java.io.IOException

Class Lexer

Field Summary

Fields inherited from class java.io.Reader

Constructor Summary

Method Summary

Methods inherited from class java.io.Reader

Methods inherited from class java.lang.Object

Field Detail

port

tentative

nesting

tokenBuffer

tokenBufferLength

Constructor Detail

Lexer

Lexer

Method Detail

pushNesting

popNesting

getPort

close

read

readUnicodeChar

readCodePoint

read

unread

peek

skip

unread

unread_quick

checkNext

skip_quick

getMessages

setMessages

checkErrors

getErrors

seenErrors

clearErrors

error

error

error

fatal

eofError

eofError

readOptionalExponent

readDelimited

readDigitsInBuffer

readDigits

readIntDigits

getName

getLineNumber

getColumnNumber

isInteractive

setInteractive

isTentative

setTentative

tokenBufferAppend

tokenBufferString

mark

reset