https://github.com/chaosinventor/parse-ebnf
Parser for EBNF written in python
https://github.com/chaosinventor/parse-ebnf
ebnf parser python
Last synced: 4 months ago
JSON representation
Parser for EBNF written in python
- Host: GitHub
- URL: https://github.com/chaosinventor/parse-ebnf
- Owner: ChaosInventor
- License: mit
- Created: 2023-08-05T18:41:01.000Z (about 2 years ago)
- Default Branch: main
- Last Pushed: 2024-08-31T11:30:35.000Z (about 1 year ago)
- Last Synced: 2025-05-23T11:38:04.619Z (5 months ago)
- Topics: ebnf, parser, python
- Language: Python
- Homepage:
- Size: 152 KB
- Stars: 5
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# Parse EBNF
[](https://pypi.org/project/parse-ebnf)
[](https://pypi.org/project/parse-ebnf)
-----
**Table of Contents**
- [Introduction](#introduction)
- [Installation](#installation)
- [Quick start](#quickstart)
- [Documentation](#documentation)
- [License](#license)
## Introduction
A simple and hacky parser for EBNF as defined by ISO. Give it an EBNF string and
it'll generate a **parse tree**. Note that this package does not parse the
described grammar.
## Installation
```console
pip install parse-ebnf
```
## Quick start
```python
from parse_ebnf.parsing import ParsingError, parse_file
try:
#Your EBNF file goes here.
pt = parse_file(ebnf_path)
partial = False
except ParsingError as e:
#If an exception occurs, a partial tree is generated. See the docs for
#details.
pt = e.parser.pt
partial = True
#Prints the text that the tree was parsed from.
print(str(pt))
#Prints a debug view of the tree.
print(repr(pt))
print(f'Parsing the file created a tree with {pt.count} nodes.')
print(f'The tree has a height of {pt.height}.')
print(f'Each node in the tree has at MOST {pt.maxDegree} children.')
def DepthFirst(node, partial, func):
#Partial nodes are in a mostly undefined state.
if not partial: func(node)
for child in node.children:
#If a node is partial, then its last child is partial. All other
#children are not partial.
if partial and child is node.children[-1]:
DepthFirst(child, True, func)
else:
DepthFirst(child, False, func)
#This will visit each node in the parse tree and print the line where its
#text begins.
DepthFirst(pt.root, partial, lambda node: print(node.startLine))
from parse_ebnf.nodes import Comment
#Finds each comment in the file and prints its text content.
for child in pt.root.children:
if isinstance(child, Comment):
#A tree being partial means that its root is partial.
if partial and child is pt.root.children[-1]: continue
print(str(child))
```
## Documentation
Check the [github page](https://chaosinventor.github.io/parse-ebnf/) that
holds the documentation.
## License
`parse-ebnf` is distributed under the terms of the [MIT](https://spdx.org/licenses/MIT.html) license.