Package gnu.text

Class Lexer

    • 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()

      • readCodePoint

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

      • 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)

      • 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)

      • 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

      • 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