Package com.yahoo.text

Class PositionedString

  • public class PositionedString
extends Object
    A string which has a current position. Useful for writing simple single-pass parsers.
    Author:
    bratseth

    • Constructor Summary

      Constructors 
      Constructor Description
      PositionedString​(String string)
      Creates this from a given string.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      String at()
      Returns a textual description of the current position, useful for appending to error messages.
      String at​(int position)
      Returns a textual description of a given position, useful for appending to error messages.
      void consume​(char c)
      Consumes the character at this position.
      boolean consumeOptional​(char c)
      Advances the position by 1 if the character at the current position is c.
      void consumeSpaces()
      Consumes zero or more whitespace characters starting at the current position
      String consumeTo​(char c)
      Sets the position of this to the next occurrence of c after the current position.
      String consumeToPosition​(int position)
      Returns the substring between the current position and position and advances the current position to position
      int indexOf​(char c)
      Returns the position of the next occurrence of c, or -1 if there are no occurrences of c in the string after the current position.
      boolean peek​(char c)
      Returns whether the character at the current position is c.
      int position()
      The current position into this string
      void setPosition​(int position)
      Assigns the current position in the string
      void skip​(int n)
      Adds n to the current position
      String string()
      The complete string value of this
      String substring()
      Returns the substring of this string from the current position to the end
      String substring​(int end)
      Returns a substring of this from the current position to the end argument
      String toString()
      Returns the string

    • Constructor Detail

      • PositionedString

        public PositionedString​(String string)
        Creates this from a given string.

    • Method Detail

      • string

        public String string()
        The complete string value of this

      • position

        public int position()
        The current position into this string

      • setPosition

        public void setPosition​(int position)
        Assigns the current position in the string

      • consume

        public void consume​(char c)
        Consumes the character at this position.
        Precondition: The character at this position is c.
        Postcondition: The position is increased by 1
        Parameters:
        c - the expected character at this
        Throws:
        IllegalArgumentException - if the character at this position is not c

      • consumeSpaces

        public void consumeSpaces()
        Consumes zero or more whitespace characters starting at the current position

      • consumeOptional

        public boolean consumeOptional​(char c)
        Advances the position by 1 if the character at the current position is c. Does nothing otherwise.
        Returns:
        whether this consumed a c at the current position, or if it did nothing

      • peek

        public boolean peek​(char c)
        Returns whether the character at the current position is c.

      • indexOf

        public int indexOf​(char c)
        Returns the position of the next occurrence of c, or -1 if there are no occurrences of c in the string after the current position.

      • skip

        public void skip​(int n)
        Adds n to the current position

      • consumeTo

        public String consumeTo​(char c)
        Sets the position of this to the next occurrence of c after the current position.
        Parameters:
        c - the char to move the position to
        Returns:
        the substring between the current position and the new position at c
        Throws:
        IllegalArgumentException - if there was no occurrence of c after the current position

      • consumeToPosition

        public String consumeToPosition​(int position)
        Returns the substring between the current position and position and advances the current position to position

      • substring

        public String substring​(int end)
        Returns a substring of this from the current position to the end argument

      • substring

        public String substring()
        Returns the substring of this string from the current position to the end

      • at

        public String at()
        Returns a textual description of the current position, useful for appending to error messages.

      • at

        public String at​(int position)
        Returns a textual description of a given position, useful for appending to error messages.