namarara/README.md

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# Namarara
Namarara is a library that parses boolean expressions, builds an [binary
expression tree](https://en.wikipedia.org/wiki/Binary_expression_tree).
Namare can also evalutes a result from a set of values corresponding the
variables used within the boolean expression.
2. binary expression
and computes a boolean result from this AST.
## Installation
Add this line to your application's Gemfile:
```ruby
gem 'mm2ep_depend'
```
And then execute:
$ bundle
Or install it yourself as:
$ gem install mm2ep_depend
## Usage
### Evaluate a single expression
```
# Initialize Namarara
namarara = Namarara.new
# Build the binary expression tree (BET)
namarara_bet = namarara.parse('this AND (that OR other) AND something_else')
# Prepare variables
variables = {
this: true,
that: false,
other: false,
something_else: true
}
# Compute tree with variables
result = namarara_bet.compute(variables)
```
### Evaluating a set of rules
```ruby
# Initialize Namarara
namarara = Namarara::Parser.new(Namarara::Lexer.new)
# A set of rules i want to check
rules = [
{name: 'vulnetable_person', expr: 'is_adult AND is_subordinate'},
{name: 'has_constraints', expr: 'is_adult AND has_children' },
{name: 'is_child', expr: 'NOT is_adult'}
# ...
]
# A set of values i want to inject (values can come from HTTP or from database
# as long as they are expressed as strings)
namarara.names = {
"is_adult" => 'false',
"is_subordinate" => 'true',
"has_children" => 'true'
}
rules.map do |rule|
namarara_bet = namarara.parse(rule)
result = namarara_bet.compute
if result then
warnings << "Rule #{rule} is true"
end
end
if not warnings.empty?
puts "Attention: vous collectez des DCP de personnes vulnerables"
puts warnings.join("\n")
else
puts "Rien à dire :-)"
end
TODO: Write usage instructions here
## Development
After checking out the repo, run `bin/setup` to install dependencies. Then, run `rake test` to run the tests. You can also run `bin/console` for an interactive prompt that will allow you to experiment.
To install this gem onto your local machine, run `bundle exec rake install`. To release a new version, update the version number in `version.rb`, and then run `bundle exec rake release`, which will create a git tag for the version, push git commits and tags, and push the `.gem` file to [rubygems.org](https://rubygems.org).
## Contributing
Bug reports and pull requests are welcome on GitHub at https://github.com/[USERNAME]/mm2ep_depend.
## License
The gem is available as open source under the terms of the [MIT License](http://opensource.org/licenses/MIT).