Predicate logic with rule composition

Predicated is a simple predicate model for Ruby.

This plugin implements Flickr's machine tags as explained here[http://www.flickr.com/groups/api/discuss/72157594497877875] while still maintaining standard tagging behavior. Basically, a machine tag has a namespace, a predicate and a value in the format [namespace]:[predicate]=[value] This allows for more precise tagging as tags can have unlimited contexts provided by combinations of namespaces and predicates. These unlimited contexts also make machine tags ripe for modeling relationships between objects. Read the HasMachineTags::TagMethods class documentation for a more thorough explanation. A demo app using this plugin is here. This gem should run on all major Ruby versions and work with Rails 2.3.x and up.

Predicate provides a simple class and processors to encode and manipulate (tuple) predicates

Predicateable allows you to define predicate methods (like `admin?`) based on a method that returns a Symbol. Similar to Rails enums, with optional strict checking and prefix support.

Predicate-centric classification toolkit

Finally attr_accessor? & attr_reader? with question marks for booleans/predicates!? To get started, pick one: (1) in your class/module, add `using AttrBool::Ref`, or (2) in your class/module, add `extend AttrBool::Ext`, or (3) in your app/script (not library), include `require 'attr_bool/core_ext'`. Now simply use any: [ attr_accessor?, attr_reader?, attr_writer?, attr_bool, attr_bool?, attr_bool! ]. Keywords: attr, attribute, attributes, bool, boolean, booleans, predicate, predicates

Adds support for .predicate? methods to MiniTest (via method_missing)

Parse Cappuccino Literal predicated and sort descriptors to arel expressions

Simple predicate methods that make case statements better

Adds automatic generation of predicate methods for attributes

MetaWhere offers the ability to call any Arel predicate methods (with a few convenient aliases) on your Model's attributes instead of the ones normally offered by ActiveRecord's hash parameters. It also adds convenient syntax for order clauses, smarter mapping of nested hash conditions, and a debug_sql method to see the real SQL your code is generating without running it against the database. If you like the new AR 3.0 query interface, you'll love it with MetaWhere.

RConditions generates a bang method (for example, Array#empty!) for each predicate method (for example, Array#empty?). The bang method will return true if the predicate method returns true, otherwise it will throw an exception. The exception will include auto-generated modules that give information on predicate methods passed or failed in the bang method's execution.

Wrong provides a general assert method that takes a predicate block. Assertion failure messages are rich in detail. The Wrong idea is to replace all those countless assert_this, assert_that library methods which only exist to give a more useful failure message than "assertion failed". Wrong replaces all of them in one fell swoop, since if you can write it in Ruby, Wrong can make a sensible failure message out of it. Also provided are several helper methods, like rescuing, capturing, and d.

Capybara provides excellent error messages for its built in predicate methods: has_selector?, has_text?, has_title? etc.. but when those are used from Page Objects while exposing predicate methods from the PageObjects themselves the error messages are lost and all we get is "expected true, got false". Including this module into your PageObject by adding "include CapybaraErrorIntel::DSL" after "include Capybara::DSL" will return the heuristic error messages.

Predicate methods for those curious about their datastructures. Provides String, Array, and Hash subclasses with dynamic predicate methods that allow you to interrogate the contents of the most common Ruby datastructures in a readable, friendly fashion. Also allows you to auto-instanciate and read inquisitive datastructures straight from your `ENV` hash.

'cont_any_word' predicate for Ransack.

Restores response predicates removed from ActionDispatch::TestResponse in Rails 6

Use arel predicates directly from where.

Small DSL to create ActiveRecord (>= 3.1) attribute predicates without writing SQL.