import java.util.HashMap;

public class SymbolTable {

    private final String ALL_VALID_CHARS = "1234567890()@zxcvbnmasdfghjklqwertyuiopZXCVBNMASDFGHJKLQWERTYUIOP_;";
    private final String INITIAL_VALID_CHARS = "@MDA(";
    HashMap<String, String> map;

    // DESCRIPTION:   initializes hashmap with predefined symbols
    // PRECONDITION:  follows symbols/values from book/appendix
    // POSTCONDITION: all hashmap values have valid address integer
    public SymbolTable() {
        map = new HashMap<>();
    }


    // DESCRIPTION:   adds new pair of symbol/address to hashmap
    // PRECONDITION:  symbol/address pair not in hashmap (check contains() 1st)
    // POSTCONDITION: adds pair, returns true if added, false if illegal name
    public boolean addNewEntry(String symbol, int adress) {

        return false;
    }

    // DESCRIPTION:   returns boolean of whether hashmap has symbol or not
    // PRECONDITION:  table has been initialized
    // POSTCONDITION: returns boolean if arg is in table or not
    public boolean contains(String symbol) {

        return false;
    }

    // DESCRIPTION:   returns address in hashmap of given symbol
    // PRECONDITION:  symbol is in hashmap (check w/ contains() first)
    // POSTCONDITION: returns address associated with symbol in hashmap
    public int getAdress(String symbol) {

        return 0;
    }

    //same as part 1 but rewrite using constants
    public boolean isValidName(String symbol) {

        return false;
    }
}