Package gnu.text

Class Lexer

java.lang.Object
java.io.Reader
gnu.text.Lexer
All Implemented Interfaces:
Closeable, AutoCloseable, Readable
Direct Known Subclasses:
Lexer, LispReader, XQParser, XslTranslator
public class Lexer extends Reader
Framework for implementing lexical scanners and parsers.

  • Field Details

    • 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 Details

    • Lexer

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

    • Lexer

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

  • Method Details

    • 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 IOException
      Specified by:
      close in interface AutoCloseable
      Specified by:
      close in interface Closeable
      Specified by:
      close in class Reader
      Throws:
      IOException

    • read

      public int read() throws IOException
      Overrides:
      read in class Reader
      Throws:
      IOException

    • readUnicodeChar

      @Deprecated public int readUnicodeChar() throws IOException
      Deprecated.
      Use readCodePoint().
      Read a Unicode character (codepoint) by checking for surrogates.
      Throws:
      IOException

    • readCodePoint

      public int readCodePoint() throws IOException
      Read a Unicode character (codepoint) by checking for surrogates.
      Throws:
      IOException

    • read

      public int read(char[] buf, int offset, int length) throws IOException
      Specified by:
      read in class Reader
      Throws:
      IOException

    • unread

      public void unread(int ch) throws IOException
      Throws:
      IOException

    • peek

      public int peek() throws IOException
      Throws:
      IOException

    • skip

      public void skip() throws IOException
      Throws:
      IOException

    • unread

      protected void unread() throws IOException
      Throws:
      IOException

    • unread_quick

      protected void unread_quick() throws IOException
      Throws:
      IOException

    • checkNext

      public boolean checkNext(char ch) throws 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:
      IOException

    • skip_quick

      protected void skip_quick() throws IOException
      Throws:
      IOException

    • getMessages

      public SourceMessages getMessages()

    • setMessages

      public void setMessages(SourceMessages messages)

    • checkErrors

      public boolean checkErrors(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, String filename, int line, int column, String message)

    • error

      public void error(char severity, String message)

    • error

      public void error(String message)

    • fatal

      public void fatal(String message) throws SyntaxException
      Throws:
      SyntaxException

    • eofError

      public void eofError(String msg) throws SyntaxException
      Throws:
      SyntaxException

    • eofError

      public void eofError(String message, int startLine, int startColumn) throws SyntaxException
      Throws:
      SyntaxException

    • readOptionalExponent

      public int readOptionalExponent() throws 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:
      IOException

    • readDelimited

      public boolean readDelimited(String delimiter) throws 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:
      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 IOException
      Throws:
      IOException

    • readIntDigits

      public int readIntDigits() throws IOException
      Throws:
      IOException

    • getName

      public 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 String tokenBufferString()

    • mark

      public void mark() throws IOException
      Start tentative parsing. Must be followed by a reset.
      Throws:
      IOException

    • reset

      public void reset() throws IOException
      Stop tentative parsing. Return to position where we called mark.
      Overrides:
      reset in class Reader
      Throws:
      IOException