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.

• 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.) algorithm is supported

$ gem install lrama

From source codes,

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

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

# "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

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" therefore keep this branch for Bison compatible branch.

1. Install Lrama
2. Run make YACC=lrama

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

See LEGAL.md file.