https://github.com/sco1/pylox

A Python implementation of the Lox programming language. Check out https://craftinginterpreters.com/
https://github.com/sco1/pylox

lox lox-interpreter python python3 python310

Last synced: 11 months ago
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A Python implementation of the Lox programming language. Check out https://craftinginterpreters.com/

• Host: GitHub
• URL: https://github.com/sco1/pylox
• Owner: sco1
• License: mit
• Created: 2021-10-26T19:26:33.000Z (over 4 years ago)
• Default Branch: main
• Last Pushed: 2025-04-08T14:32:10.000Z (12 months ago)
• Last Synced: 2025-05-07T22:46:51.144Z (11 months ago)
• Topics: lox, lox-interpreter, python, python3, python310
• Language: Python
• Homepage:
• Size: 410 KB
• Stars: 4
• Watchers: 1
• Forks: 0
• Open Issues: 14
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md
  • License: LICENSE

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README

          
# pylox

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[![PyPI](https://img.shields.io/pypi/v/sco1-pylox?logo=Python&logoColor=FFD43B)](https://pypi.org/project/sco1-pylox/)

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## Introduction

This is my Python implementation of an interpreter for the Lox programming language from Robert Nystrom's *[Crafting Interpreters](https://craftinginterpreters.com/)*.

## Python?

While the text is implemented in Java and C as its high & low-level implementations, I have no idea how to write either of them! Instead, I'll be using Python for the high-level implementation & eventually Rust for the low-level imeplementation.

## Differences From Text

For the sake of fitting within a decently sized text, the fully implemented Lox spec omits features that users of other programming languages may miss. Often these are discussed as notes within a chapter, or presented as challenges at the end of a chapter. Significant difference in this implementation from the text reference are noted below.

### Defined by Challenges

  * (Chapter 4): Arbitrarily nested block comments (`/* ... */`)

  * (Chapter 9): `break` statements are available for `for` and `while` loops

### User Choice

  * Division by zero returns `NaN` (Python's `float('nan')`)

  * Strings may be defined using either `"` or `'`

  * Modulo operator (`%`)

  * Power operator (`^`)

  * Integer division operator (`\`)

  * Both floats and integers are represented

    * Return type from operations follows Python3's semantics

  * Containers

    * `array()`

  * A basic `include` header system

    * Supports "stdlib" imports (``) and path imports (`"path/to/file"`)

    * Recursive `include` not supported

    * Imported source assumed to be valid code

### Additional Built-ins:

Unless otherwise noted, behavior mirrors the similarly named Python function.

#### General

  * `input`

  * `len`

  * `ord`

  * `read_text` (via `pathlib.Path.read_text`)

  * `str2num`

  * `string_array`

    * Gives a `LoxArray` whose contents are equivalent to `collections.deque()`

#### Math

  * `abs`

  * `ceil`

  * `divmod`

  * `floor`

  * `max`

  * `min`

#### Regex

For methods whose Python equivalent returns [Match objects](https://docs.python.org/3/library/re.html#match-objects), a `LoxArray` is returned. The first value in the array will always correspond to `match.group(0)`; if the pattern contains one or more groups then the array will match the output of `match.groups()`

  * `re_findall`

  * `re_match`

  * `re_search`

  * `re_sub`

#### Stats

  * `mean`

  * `median`

  * `mode`

  * `std`

### Pure lox headers

  * ``

  * ``

  * ``

  * ``