Class MathParser

MathParser/src/com/aghajari/math/MathParser.java:116–1133

A simple but powerful math parser for java. MathParser parser = new MathParser(); // start parser.addExpression("f(x, y) = 2(x + y)"); // addFunction parser.addExpression("x0 = 1 + 2 ^ 2"); // addVariabl

 * @version 1.0.0
 */
public class MathParser implements Cloneable {

    /**
     * {@link #setRoundEnabled(boolean)}
     */
    private boolean roundEnabled = true;
    private int roundScale = 6;

    private final ArrayList<MathVariable> variables = new ArrayList<>();
    private final ArrayList<MathFunction> functions = new ArrayList<>();
    private final ArrayList<MathVariable> innerVariables = new ArrayList<>();
    private final AtomicInteger tmpGenerator = new AtomicInteger(0);

    /* The order of operations */
    static final char[] order = {'%', '^', '*', '/', '+', '-'};

    /* The priority of operations connected to order[] */
    static final int[] orderPriority = {3, 2, 1, 1, 0, 0};

    /* Special characters will end name of variables or functions */
    static final char[] special = {'%', '^', '*', '/', '+', '-', ',', '(', ')', '!', '=', '<', '>'};

    /* Basic math operations that parser supports */
    static final HashMap<Character, MathOperation> operations = new HashMap<>();

    static {
        operations.put('^', Math::pow);
        operations.put('*', (a, b) -> a * b);
        operations.put('/', (a, b) -> a / b);
        operations.put('+', Double::sum);
        operations.put('-', (a, b) -> a - b);
        operations.put('%', (a, b) -> a % b);
    }

    private MathParser() {
    }

    public static MathParser create() {
        return new MathParser();
    }

    /**
     * Parses and calculates the expression
     *
     * @param expression the expression to parse and calculate
     * @throws MathParserException                   If something went wrong
     * @throws BalancedParenthesesException          If parentheses aren't balanced
     * @throws MathInvalidParameterException         If parameter of the function is invalid
     * @throws MathFunctionInvalidArgumentsException If the number of arguments is unexpected
     * @throws MathFunctionNotFoundException         If couldn't find the function
     * @throws MathVariableNotFoundException         If couldn't find the variable
     */
    public double parse(String expression) throws MathParserException {
        String org = expression;
        validate(expression);
        try {
            initDefaultVariables();
            expression = firstSimplify(expression);