Tagformula::Parser

Match tag formulas with simple boolean operations against lists of strings. e.g. the formula "foo & ! bar" would match ['foo'], but not ['foo', 'bar']

Add this line to your application's Gemfile:

gem 'tagformula'

And then execute:

$ bundle

Or install it yourself as:

$ gem install tagformula

Tagformula::Parser matches arrays of strings against formulas which require the presence or absence of strings in the array. Conditions can be nested (in brackets), or negated (with a !) and can be 'and' ('&') or 'or' ('|') conditions.

require 'tagformula/parser'

formula = Tagformula::Parser.parse("alpha & beta")

formula.matches?(%w[alpha beta])  # => true
formula.matches?(%w[alpha gamma]) # => false

formula = Tagformula::Parser.parse("alpha & (beta | gamma)")

formula.matches?(%w[alpha beta])  # => true
formula.matches?(%w[alpha gamma]) # => true

formula = Tagformula::Parser.parse("alpha & !beta")

formula.matches?(%w[alpha beta])  # => false
formula.matches?(%w[alpha gamma]) # => true

expr & expr requires both expressions to be present

expr | expr requires either expression to be present

expr1 & ! expr2 requires the expr1 to be present and expr2 to be absent.

"true" and "yes" will always match as true.

"false" and "no" will always match as false.

1. Fork it ( http://github.com/geoffyoungs/tagformula/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request