Contents

# Lrama

Lrama is LALR (1) parser generator written by Ruby. The first goal of this project is providing error tolerant parser for CRuby with minimal changes on CRuby parse.y file.

## Features

* Bison style grammar file is supported with some assumptions
  * b4_locations_if is always true
  * b4_pure_if is always true
  * b4_pull_if is always false
  * b4_lac_if is always false
* Error Tolerance parser
  * Subset of [Repairing Syntax Errors in LR Parsers (Corchuelo et al.)](https://idus.us.es/bitstream/handle/11441/65631/Repairing%20syntax%20errors.pdf) algorithm is supported

## Installation

```shell
$ gem install lrama
```

From source codes,

```shell
$ cd "$(lrama root)"
$ bundle install
$ bundle exec rake install
$ bundle exec lrama --version
0.5.0
```

## Usage

```shell
# "y.tab.c" and "y.tab.h" are generated
$ lrama -d sample/parse.y
```

```shell
# "calc", "calc.c", and "calc.h" are generated
$ lrama -d sample/calc.y -o calc.c && gcc -Wall calc.c -o calc && ./calc
Enter the formula:
1
=> 1
1+2*3
=> 7
(1+2)*3
=> 9
```

## Versions and Branches

### v0_4 (`lrama_0_4` branch)

This branch generates "parse.c" compatible with Bison 3.8.2 for ruby 3.0, 3.1, 3.2. The first version migrated to ruby is ["0.4.0"](https://github.com/ruby/ruby/pull/7798) therefore keep this branch for Bison compatible branch.

## Build Ruby

1. Install Lrama
2. Run `make YACC=lrama`

## Release flow

1. Update `Lrama::VERSION`
2. Release as a gem by `rake release`
3. Update Lrama in ruby/ruby by `cp -r exe lib ruby/tool/lrama`
4. Create new release on [GitHub](https://github.com/ruby/lrama/releases)

## License

See LEGAL.md file.

Version data entries

1 entries across 1 versions & 1 rubygems

Version	Path
lrama-0.5.1	README.md