jlox

Lox

 // 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       → "==" | "!=" | "<" | "<=" | ">" | ">="
  | "+"  | "-"  | "*" | "/" ;