Behavioral Design Patterns in C++ - Boolean Evaluator

The lecture covers implementing a lexer and parser without using the interpreter design pattern. It starts with setting up a project and creating two functions: one for the lexer and another for the parser. The lexer uses C++ string streams to tokenize input, while the parser evaluates boolean expressions. The lecture concludes by discussing the limitations of the current implementation and suggests refactoring using the Interpreter Design Pattern for better flexibility and maintainability.

What is the primary purpose of the lexer function in the implementation?

• To interpret the tokens

• To compile the code

• To tokenize the input string

• To execute the parsed code

What does the parser function return in this implementation?

• An integer

• A list of tokens

• A boolean

• A string

Which function is used to convert a token into a boolean value?

• toInt

• toBool

• toString

• toFloat

What is the first step when the parser encounters an AND operator?

• Return false immediately

• Convert the operator to a number

• Look ahead to the next token

• Ignore the operator

What happens if one of the operands in an expression is zero?

• The expression is ignored

• The expression is re-evaluated

• The expression returns false

• The expression returns true

What is a limitation of the current parser implementation?

• It cannot handle any operators

• It requires modification for new rules

• It uses too many classes

• It is too fast

What design pattern is suggested for simplifying the implementation?

• Singleton Pattern

• Factory Pattern

• Interpreter Pattern

• Observer Pattern