Package nonapi.io.github.classgraph.types

Class Parser

  • Direct Known Subclasses:
    JSONParser
    public class Parser
extends java.lang.Object
    A generic PEG parser.

    • Field Summary

      Fields 
      Modifier and Type Field Description
      private int position
      The current position.
      private static int SHOW_AFTER
      How much context to show after the current position.
      private static int SHOW_BEFORE
      How much context to show before the current position.
      private java.lang.Object state
      Extra parsing state.
      private java.lang.String string
      The string being parsed.
      private java.lang.StringBuilder token
      The token buffer.

    • Constructor Summary

      Constructors 
      Constructor Description
      Parser​(java.lang.String string)
      Construct a parser.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void advance​(int numChars)
      Advance numChars character positions.
      void appendToToken​(char c)
      Append the given character to the token buffer.
      void appendToToken​(java.lang.String str)
      Append the given string to the token buffer.
      java.lang.String currToken()
      Get the current token, and reset the token to empty.
      void expect​(char expectedChar)
      Expect the next character.
      char getc()
      Get the next character.
      int getPosition()
      Get the current position.
      java.lang.String getPositionInfo()
      Get the parsing context as a string, for debugging.
      java.lang.Object getState()
      Get the "state object" from the parser (can be used to parse state between parser functions).
      java.lang.CharSequence getSubsequence​(int startPosition, int endPosition)
      Return a subsequence of the input string.
      java.lang.String getSubstring​(int startPosition, int endPosition)
      Return a substring of the input string.
      boolean hasMore()
      Check to see if there are more characters to parse.
      void next()
      Advance one character without returning the value of the character.
      char peek()
      Peek at the next character without reading it.
      void peekExpect​(char expectedChar)
      Get the next character, throwing a ParseException if the next character is not the expected character.
      boolean peekMatches​(java.lang.String strMatch)
      Peek operator that can look ahead several characters.
      void setPosition​(int position)
      Set the position of the parser within the string.
      java.lang.Object setState​(java.lang.Object state)
      Set the "state object" from the parser (can be used to parse state between parser functions).
      void skipWhitespace()
      Skip whitespace starting at the current position.
      java.lang.String toString()  

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

    • Field Detail

      • string

        private final java.lang.String string
        The string being parsed.

      • position

        private int position
        The current position.

      • token

        private final java.lang.StringBuilder token
        The token buffer.

      • state

        private java.lang.Object state
        Extra parsing state.

      • SHOW_BEFORE

        private static final int SHOW_BEFORE
        How much context to show before the current position.
        See Also:
        Constant Field Values

      • SHOW_AFTER

        private static final int SHOW_AFTER
        How much context to show after the current position.
        See Also:
        Constant Field Values

    • Constructor Detail

      • Parser

        public Parser​(java.lang.String string)
       throws ParseException
        Construct a parser.
        Parameters:
        string - The string to parse.
        Throws:
        ParseException - If the string was null.

    • Method Detail

      • getPositionInfo

        public java.lang.String getPositionInfo()
        Get the parsing context as a string, for debugging.
        Returns:
        A string showing parsing context, for debugging.

      • setState

        public java.lang.Object setState​(java.lang.Object state)
        Set the "state object" from the parser (can be used to parse state between parser functions).
        Parameters:
        state - The state object.
        Returns:
        The old value of the state object.

      • getState

        public java.lang.Object getState()
        Get the "state object" from the parser (can be used to parse state between parser functions).
        Returns:
        The current value of the state object.

      • getc

        public char getc()
          throws ParseException
        Get the next character.
        Returns:
        The next character.
        Throws:
        ParseException - If there were no more characters in the string.

      • expect

        public void expect​(char expectedChar)
            throws ParseException
        Expect the next character.
        Parameters:
        expectedChar - The expected character.
        Throws:
        ParseException - If the next character was not the expected character.

      • peek

        public char peek()
        Peek at the next character without reading it.
        Returns:
        The next character, or '\0' if at the end of the string.

      • peekExpect

        public void peekExpect​(char expectedChar)
                throws ParseException
        Get the next character, throwing a ParseException if the next character is not the expected character.
        Parameters:
        expectedChar - The expected next character.
        Throws:
        ParseException - If the next character is not the expected next character.

      • peekMatches

        public boolean peekMatches​(java.lang.String strMatch)
        Peek operator that can look ahead several characters.
        Parameters:
        strMatch - The string to compare, starting at the current position, as a "peek" operation.
        Returns:
        True if the strMatch matches a substring of the remaining string starting at the current position.

      • next

        public void next()
        Advance one character without returning the value of the character.

      • advance

        public void advance​(int numChars)
        Advance numChars character positions.
        Parameters:
        numChars - The number of character positions to advance.
        Throws:
        java.lang.IllegalArgumentException - If there are insufficient characters remaining in the string.

      • hasMore

        public boolean hasMore()
        Check to see if there are more characters to parse.
        Returns:
        true if the input has not all been consumed.

      • getPosition

        public int getPosition()
        Get the current position.
        Returns:
        the current position.

      • setPosition

        public void setPosition​(int position)
        Set the position of the parser within the string.
        Parameters:
        position - The position to move to.
        Throws:
        java.lang.IllegalArgumentException - If the position is out of range.

      • getSubsequence

        public java.lang.CharSequence getSubsequence​(int startPosition,
                                             int endPosition)
        Return a subsequence of the input string.
        Parameters:
        startPosition - The start position.
        endPosition - The end position.
        Returns:
        The subsequence.

      • getSubstring

        public java.lang.String getSubstring​(int startPosition,
                                     int endPosition)
        Return a substring of the input string.
        Parameters:
        startPosition - The start position.
        endPosition - The end position.
        Returns:
        The substring.

      • appendToToken

        public void appendToToken​(java.lang.String str)
        Append the given string to the token buffer.
        Parameters:
        str - The string to append.

      • appendToToken

        public void appendToToken​(char c)
        Append the given character to the token buffer.
        Parameters:
        c - The character to append.

      • skipWhitespace

        public void skipWhitespace()
        Skip whitespace starting at the current position.

      • currToken

        public java.lang.String currToken()
        Get the current token, and reset the token to empty.
        Returns:
        The current token. Resets the current token to empty.

      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object