基于JavaScript的公式解释器 - 9 【逻辑操作符的实现】

function OperatorBinaryLogicBase() {
    this.DeriveFrom(new OperatorBinaryBase());
    this.set_ClassName("OperatorBinaryLogicBase");
    this.set_Sign("undefined");
};

function OperatorUnaryLogicBase() {
    this.DeriveFrom(new OperatorUnaryBase());
    this.set_ClassName("OperatorUnaryLogicBase");
    this.set_Sign("undefined");
};

function OperatorLogicAnd() {
    this.DeriveFrom(new OperatorBinaryLogicBase());
    this.set_ClassName("OperatorLogicAnd");
    this.set_Sign("&&");
};

OperatorLogicAnd.prototype.Evaluate = function(operands) {
    var values = this._getTwoNumberOperands(operands);

    return new OperandBoolean(values[0].get_Value() && values[1].get_Value());
};

function OperatorLogicOr() {
    this.DeriveFrom(new OperatorBinaryLogicBase());
    this.set_ClassName("OperatorLogicOr");
    this.set_Sign("||");
};

OperatorLogicOr.prototype.Evaluate = function(operands) {
    var values = this._getTwoNumberOperands(operands);

    return new OperandBoolean(values[0].get_Value() || values[1].get_Value());
};

function OperatorLogicNot() {
    this.DeriveFrom(new OperatorUnaryLogicBase());
    this.set_ClassName("OperatorLogicOr");
    this.set_Sign("!");
};

OperatorLogicNot.prototype.Evaluate = function(operands) {
    var val = this.GetOneNumberOperand(operands);

    return new OperandBoolean(!val.get_Value());
};