jlox

Interpreter for the Lox programming language implemented in Java.
Implementation of the interpreter follows guidelines provided by the book
Crafting Interpreters written by
Robert Nystorm.

Build and Run

Dependencies

1. JDK (Java Development Toolkit)
2. Maven

Steps

1. Clone the repository

git clone git@github.com:peshala-prabhapoorna/jlox.git

2. Move into the root of the repository

cd jlox

3. Build the interpreter

mvn clean compile

4. Run the interpreter

./jlox

Build Jar File

mvn clean compile package

grammar

program        → declaration* EOF ;
declaration    → varDecl | statement ;
statement      → exprStmt
                | forStmt
                | ifStmt
                | printStmt
                | whileStmt
                | block ;
forStmt        → "for" "(" ( varDecl | exprStmt | ";")
                expression? ";"
                expression? ")" statement ;
block          → "{" declaration* "}" ;
varDecl        → "var" IDENTIFIER ( "=" expression )? ";" ;
exprStmt       → expression ";" ;
ifStmt         → "if" "(" expression ")" statement ( "else" statement )? ;
printStmt      → "print" expression ";" ;
whileStmt      → "while" "(" expression ")" statement ;
expression     → assignment ;
assignment     → IDENTIFIER "=" assignment | comma ;
comma          → conditional ( "," conditional )* ;
conditional    → logic_or ( "?" expression ":" conditional )? ;
logic_or       → logic_and ( "or" logic_and )* ;
logic_and      → equality ( "and" equality )* ;
equality       → comparison ( ( "!=" | "==" ) comparison )* ;
comparison     → term ( ( ">" | ">=" | "<" | "<=" ) term )* ;
term           → factor ( ( "-" | "+" ) factor )* ;
factor         → unary ( ( "/" | "*" ) unary )* ;
unary          → ( "!" | "-" ) unary | call ;
call           → primary ( "(" arguments? ")" )* ;
arguments      → expression ( "," expression )* ;
primary        → NUMBER | STRING | "true" | "false" | "nil"
               | "(" expression ")"
               | IDENTIFIER
               // Error productions...
               | ( "!=" | "==" ) equality
               | ( ">" | ">=" | "<" | "<=" ) comparison
               | ( "+" ) term
               | ( "/" | "*" ) factor ;