https://github.com/paulzfm/ll1pg

Yet another LL(1) parser generation tool, built in principle.
https://github.com/paulzfm/ll1pg

ll1 parser-generator

Last synced: 10 days ago
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Yet another LL(1) parser generation tool, built in principle.

• Host: GitHub
• URL: https://github.com/paulzfm/ll1pg
• Owner: paulzfm
• Created: 2017-04-07T08:13:48.000Z (over 7 years ago)
• Default Branch: master
• Last Pushed: 2019-10-03T14:36:36.000Z (about 5 years ago)
• Last Synced: 2024-08-03T01:39:20.933Z (4 months ago)
• Topics: ll1, parser-generator
• Language: Scala
• Homepage:
• Size: 5.2 MB
• Stars: 7
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# ll1pg

[![Build Status](https://api.cirrus-ci.com/github/paulzfm/ll1pg.svg)](https://cirrus-ci.com/github/paulzfm/ll1pg)

Yet another parser generation tool.

It can generate either a parser class or a LL prediction table in Java.

The input specification file must specify a LL(1) grammar.

This tool is now a part of the [decaf](https://github.com/decaf-lang/decaf) project for the undergraduate course 

_Principles of Compilation_ in Tsinghua University.

## Build

Prebuilt jars will be updated in the release page.

To build from source, simply type `./gradlew build`.

To assemble a standalone jar with all dependencies, type `./gradlew assembly` and you'll find it at `build/libs/`.

## Usage

```

java -jar ll1pg.jar [-parser | -table | -check]  

```

where `` is the destination folder for the generated parser, and `` is the

path of the specification file.

The options mean:

- `-parser`: generate a Java parser

- `-table`: generate a LL predication table

- `-check`: simply check if a grammar is LL(1), or else warnings will be reported

See [here](https://github.com/paulzfm/ll1pg/wiki/1.-Specification-File) for the definition of specification file.

And [here](https://github.com/paulzfm/ll1pg/wiki/2.-Resolving-Conflicts) for how we resolve conflicts

even when your grammar is not LL(1).

We strongly recommend you to read our [wiki](https://github.com/paulzfm/ll1pg/wiki) first.

## Demo Projects

To integrate our tool with your project better, please take a closer look at our

demo project [arith](https://github.com/paulzfm/ll1pg/tree/master/demos/arith),

which implements a simple calculator.

Also, the [decaf](https://github.com/decaf-lang/decaf) project is a good practice.