## Lox
```c
 // Your first Lox program!
 print "Hello, world!";
```
- Dynamic typing
- Automatic memory management
- Data Types
  - Booleans
  - Numbers
  - Strings
  - Nil
- Expressions
  - Arithmetic
  - Comparison and equality
  - Logical operators
  - Precedence and grouping
- Statements
- Variables
- Control Flow
- Functions
- Closures
- Classes

## A Grammar for Lox expressions

- **Literals**. Numbers,strings,Booleans, and nil
- **Unary expressions.** A prefix ! to perform a logical not, and - to negate a number.
- **Binary expressions.** The infix arithmetic(+,-,*,/) and logic operators (==, !=, <, <=,>,>=)
- **Parentheses.** A pair of ( and ) wrapped around and expression.

  - Syntax tree
  
    ```
    expression     → literal
    | unary
    | binary
    | grouping ;
  
    literal        → NUMBER | STRING | "true" | "false" | "nil" ;
    grouping       → "(" expression ")" ;
    unary          → ( "-" | "!" ) expression ;
    binary         → expression operator expression ;
    operator       → "==" | "!=" | "<" | "<=" | ">" | ">="
    | "+"  | "-"  | "*" | "/" ;
  
    ```