Package org.apache.uima.internal.util

Class SymbolTable

java.lang.Object
org.apache.uima.internal.util.SymbolTable
public class SymbolTable extends Object
The SymbolTable class provides a generic symbol table. A symbol table is a bijective mapping between strings and integers. Symbol numbering starts at a point defined by the user, which is 0 by default. A SymbolTable provides quick access to symbol numbers (code points) through a hash table. The reverse map is facilitated through a separate vector of the symbols. This is memory intensive, but much faster than searching through the hashtable.

  • Constructor Summary

    Constructors
    Constructor
    Description
    SymbolTable()
    Default constructor
    SymbolTable(int start)
    Use this constructor if you need your symbol numbering to start at a different point than 0.
    SymbolTable(String[] names)
    Init the symbol table from an array of strings, where code points correspond to array positions.

  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    contains(String symbol)
     
    SymbolTable
    copy()
    Perform a deep copy.
    int
    get(String symbol)
    Get value of symbol in table.
    int
    getStart()
    Get the starting number of the symbol table.
    String
    getSymbol(int i)
    Find the symbol corresponding to a value.
    static SymbolTable
    readFromFile(String filename)
    Read a file line by line, and create an entry for each line.
    int
    set(String symbol)
    Create new symbol in table.
    int
    size()
    Returns number of symbols in table.
    String
    toString()
    Returns the string representation of the internal hash table.

    Methods inherited from class java.lang.Object

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

  • Constructor Details

    • SymbolTable

      public SymbolTable(int start)
      Use this constructor if you need your symbol numbering to start at a different point than 0.
      Parameters:
      start - The code point of the first symbol added to the table. Subsequent symbols will have larger code points.

    • SymbolTable

      public SymbolTable()
      Default constructor

    • SymbolTable

      public SymbolTable(String[] names)
      Init the symbol table from an array of strings, where code points correspond to array positions. Warning: if the array contains duplicate strings, the numbering will be off!
      Parameters:
      names - The String array containing the symbols.

  • Method Details

    • contains

      public boolean contains(String symbol)

    • getStart

      public int getStart()
      Get the starting number of the symbol table.
      Returns:
      The start of the table.

    • copy

      public SymbolTable copy()
      Perform a deep copy.
      Returns:
      A copy of this.

    • set

      public int set(String symbol)
      Create new symbol in table. If the symbol already exists, only the symbol's number is returned. Use get() if you need to find out if the symbol is already in the table.
      Parameters:
      symbol - the input string to be put in the table.
      Returns:
      the symbol's number.

    • get

      public int get(String symbol)
      Get value of symbol in table.
      Parameters:
      symbol - the input string.
      Returns:
      the symbol's number, if the symbol is in the table, and start-1, else (where start is the code point of the first symbol).

    • getSymbol

      public String getSymbol(int i)
      Find the symbol corresponding to a value.
      Parameters:
      i - the number that we want to get the string value for.
      Returns:
      the symbol corresponding to the input number, if it exists, and null, else.

    • size

      public int size()
      Returns number of symbols in table.
      Returns:
      The number of symbols in the table.

    • toString

      public String toString()
      Returns the string representation of the internal hash table.
      Overrides:
      toString in class Object
      Returns:
      A string representing the symbol table.

    • readFromFile

      public static SymbolTable readFromFile(String filename) throws IOException
      Read a file line by line, and create an entry for each line. Empty lines are ignored. Lines containing only whitespace are not.
      Parameters:
      filename - The name of the file to be read in.
      Returns:
      The SymbolTable created from the file.
      Throws:
      IOException - Errors reading in the file.