++ed by:
TOBYINK
Author image David Farrell
and 1 contributors

NAME

Lox - A Perl implementation of the Lox programming language

DESCRIPTION

A Perl translation of the Java Lox interpreter from Crafting Interpreters.

INSTALL

As long as you have Perl 5.24.0 or greater, you should be able to run plox from the root project directory.

If you'd rather build and install it:

  $ perl Makefile.PL
  $ make
  $ make test
  $ make install

SYNOPSIS

If you have built and installed plox:

  $ plox
  Welcome to Perl-Lox version 0.02
  >

  $ plox hello.lox
  Hello, World!

Otherwise from the root project directory:

  $ perl -Ilib bin/plox
  Welcome to Perl-Lox version 0.02
  >

  $ perl -Ilib bin/plox hello.lox
  Hello, World!

Pass the --debug or -d option to plox to print the tokens it scanned and the parse tree.

TESTING

The test suite includes 238 test files from the Crafting Interpreters repo.

  $ prove -l t/*

EXTENSIONS

Perl-Lox has these capabilities from the "challenges" sections of the book:

  • Anonymous functions fun () { ... }

  • Break statements in loops

  • Multi-line comments /* ... */

  • New Exceptions:

    • Evaluating an uninitialized variable

DIFFERENCES

Differences from the canonical "jlox" implementation:

  • repl is stateful

  • signed zero is unsupported

  • methods are equivalent

    Prints "true" in plox and "false" in jlox:

      class Foo  { bar () { } } print Foo().bar == Foo().bar;

AUTHOR

Copyright 2020 David Farrell

LICENSE

See LICENSE file.