Add benchmarks

Author: peterfication

README.md

@@ -25,6 +25,7 @@ Enum-like behavior for Ruby, heavily inspired by [this](http://www.rubyfleebie.c
   - [Duplicate enumerator keys or duplicate values](#duplicate-enumerator-keys-or-duplicate-values)
   - [Inheritance](#inheritance)
   - [Exhaustive case matcher](#exhaustive-case-matcher)
+- [Benchmarks](#benchmarks)
 - [Contributing](#contributing)
 - [Copyright and License](#copyright-and-license)
 - [Related Projects](#related-projects)
@@ -264,7 +265,7 @@ ShippedOrderState.values # ['CREATED', 'PAID', 'PREPARED', SHIPPED']
 
 If you want to make sure that you cover all cases in a case stament, you can use the exhaustive case matcher: `Ruby::Enum::Case`. It will raise an error if a case/enum value is not handled, or if a value is specified that's not part of the enum. This is inspired by the [Rust Pattern Syntax](https://doc.rust-lang.org/book/ch18-03-pattern-syntax.html). If multiple cases match, all matches are being executed. The return value is the value from the matched case, or an array of return values if multiple cases matched.
 
-> NOTE: This will add checks at runtime which might lead to slightly worse performance.
+> NOTE: This will add checks at runtime which might lead to worse performance. See [benchmarks](#benchmarks).
 
 > NOTE: `:else` is a reserved keyword if you want to use `Ruby::Enum::Case`.
 
@@ -299,6 +300,14 @@ Color.Case(color, {
 })
 ```
 
+## Benchmarks
+
+Benchmark scripts are defined in the [`benchmarks`](benchmarks) folder and can be run with Rake:
+
+```console
+rake benchmarks:case
+```
+
 ## Contributing
 
 You're encouraged to contribute to ruby-enum. See [CONTRIBUTING](CONTRIBUTING.md) for details.

Rakefile

@@ -16,3 +16,10 @@ require 'rubocop/rake_task'
 RuboCop::RakeTask.new(:rubocop)
 
 task default: %i[rubocop spec]
+
+namespace :benchmark do
+  desc 'Run benchmark for the Ruby::Enum::Case'
+  task :case do
+    require_relative 'benchmarks/case'
+  end
+end

benchmarks/case.rb

@@ -0,0 +1,45 @@
+# frozen_string_literal: true
+
+$LOAD_PATH.unshift(File.join(File.dirname(__FILE__), '..', 'lib'))
+
+require 'benchmark'
+require 'ruby-enum'
+
+##
+# Test enum
+class Color
+  include Ruby::Enum
+  include Ruby::Enum::Case
+
+  define :RED, :red
+  define :GREEN, :green
+  define :BLUE, :blue
+end
+
+puts 'Running 1.000.000 normal case statements'
+case_statement_time = Benchmark.realtime do
+  1_000_000.times do
+    case Color::RED
+    when Color::RED, Color::GREEN
+      'red or green'
+    when Color::BLUE
+      'blue'
+    end
+  end
+end
+
+puts 'Running 1.000.000 ruby-enum case statements'
+ruby_enum_time = Benchmark.realtime do
+  1_000_000.times do
+    Color.case(Color::RED,
+               {
+                 [Color::RED, Color::GREEN] => -> { 'red or green' },
+                 Color::BLUE => -> { 'blue' }
+               })
+  end
+end
+
+puts "ruby-enum case: #{ruby_enum_time.round(4)}"
+puts "case statement: #{case_statement_time.round(4)}"
+
+puts "ruby-enum case is #{(ruby_enum_time / case_statement_time).round(2)} times slower"