cmdneo / tree_lox

Tree-walk interpreter for Lox written in Go.

Tree-Lox

A tree-walk interpreter for the lox language as described in the book "Crafting Interpreters" written in Go.

It can execute lox scripts from a given file or can be launched in REPL mode:

lox <file-name> # Run from a file
lox             # Start the REPL

Additional features

• Strings can be compared lexicographically using the comparison operators
• Ternary operator (:?)
• break and continue statements
• assert statement

Built-in Functions

• clock(): Returns the time since January 1 1970, 00:00:00 (UNIX-epoch) in seconds
• sleep(<time-in-seconds>): Pause execution of the script for the given time
• string(<value>): Convert a Lox object to its string representation
• len(<string>): Calculate the length of a string in bytes
• instanceof(<instance>, <class>): Check whether an instance is of a specific class.
• hasattr(<instance>, <name>),
• getattr(<instance>, <name>),
• delattr(<instance>, <name>) and
• setattr(<instance>, <name>, <value>): Functions for manipulating instance attributes

Examples

Fibonacci numbers

fun fib(n) {
	if (n <= 1) return 1;
	return fib(n - 1) + fib(n - 2);
}

for (var i = 0; i < 20; i = i + 1) {
	print fib(i);
}

Building

From the project root directory run:

go build