jlox

Crafting Interpreters

Install

yarn global add jlox

or

npm install -g jlox

Usage

jlox --path=<FILE.EXT>

Syntax

Variables

var a = 123;
var b;
b = 223;
var c = "hello world";

Print

print "hello world";
print 3 * 4;

Comment

var name = "John"; // username
print name;

Operators

(5 + 6) * 10 - 12 / 3;

Expressions

var a = 5;
print a * 5;
print "John" + " " + "Doe";
// 25
// John Doe

Conditional Execution

var a = 3;
if (a < 4)
    print 111;
else
    print 222;
// 111

Logical Operators

print "hi" or 2; // "hi".
print nil or "yes"; // "yes".

var a = 3;
if (a > 2 and a == 3)
    print("if statement");
else
    print("else statement");
// if statement

For Loop

var a = 0;
var temp;

for (var b = 1; a < 10000; b = temp + b) {
    print a;
    temp = a;
    a = b;
}

While Loop

var a = 1;
while (a < 10) {
    print a;
    a = a + 1;
}

Function

fun sayHi(first, last) {
  return "Hi, " + first + " " + last + "!";
}

print sayHi("Dear", "Reader"); // Hi, Dear Reader!

Class

class Breakfast {
    cook(something) {
        print "cook " + something + ".";
    }
}

Breakfast().cook("egg");

Inherit

class Doughnut {
  cook() {
    print "Fry until golden brown.";
  }
}

class BostonCream < Doughnut {
  cook() {
    super.cook();
    print "Pipe full of custard and coat with chocolate.";
  }
}

BostonCream().cook();