From 5959e9dc8d852906dc617cd5e1330157b42fd1d9 Mon Sep 17 00:00:00 2001
From: Mike Cifelli <michael.cifelli@gmail.com>
Date: Sat, 26 Jan 2019 14:41:19 -0500
Subject: [PATCH] Update readme

---
 README.md                     | 46 +++++++++++++++++++++++++++++++++++
 mutual_recursion.gemspec      |  2 +-
 test/mutual_recursion_test.rb |  8 +++---
 3 files changed, 52 insertions(+), 4 deletions(-)

diff --git a/README.md b/README.md
index e69de29..22b1450 100644
--- a/README.md
+++ b/README.md
@@ -0,0 +1,46 @@
+# Mutual Recursion
+
+Tail call optimization for mutually (and directly) recursive functions in Ruby.
+
+The current desing uses a trampoline. However, it is implemented in a way that still allows a tail recursive function to return a Proc as its terminal value without it being called prematurely by accident. 
+### examples
+```ruby
+require 'mutual_recursion'
+
+def mutual_one(x, y = 0)
+  return terminal_value(y) if x.negative?
+
+  tail_call { mutual_two(x, y + 1) }
+end
+
+def mutual_two(x, y)
+  tail_call { mutual_one(x - 1, y) }
+end
+
+mutual_one(50_000).invoke
+# => 50001
+```
+```ruby
+require 'mutual_recursion'
+
+def direct(x, y = 0)
+  return terminal_value(y) if x.negative?
+
+  tail_call { direct(x - 1, y + 1) }
+end
+
+direct(50_000).invoke
+# => 50001
+```
+```ruby
+require 'mutual_recursion'
+
+def proc_returning(x, y = 0)
+  return terminal_value(proc { "|#{y}|" }) if x.negative?
+
+  tail_call { proc_returning(x - 1, y + 1) }
+end
+
+proc_returning(20).invoke.call
+# => "|21|"
+```
diff --git a/mutual_recursion.gemspec b/mutual_recursion.gemspec
index 0ec7766..a4de4d5 100644
--- a/mutual_recursion.gemspec
+++ b/mutual_recursion.gemspec
@@ -8,6 +8,6 @@ Gem::Specification.new do |s|
   s.description = 'Tail call optimization for mutually (and directly) recursive functions using a trampoline.'
   s.authors     = ['Mike']
   s.files       = ['lib/mutual_recursion.rb']
-  s.homepage    = ''
+  s.homepage    = 'https://gitlab.com/mike-cifelli/mutual_recursion'
   s.license     = 'MIT'
 end
diff --git a/test/mutual_recursion_test.rb b/test/mutual_recursion_test.rb
index 0b7e5af..4f5fa80 100644
--- a/test/mutual_recursion_test.rb
+++ b/test/mutual_recursion_test.rb
@@ -37,7 +37,7 @@ class InventoryTest < Minitest::Test
   end
 
   def test_recursive_function_can_return_proc
-    tail = proc_returning
+    tail = proc_returning(20)
     assert_kind_of(Proc, tail.invoke)
   end
 
@@ -76,8 +76,10 @@ def lambda_returning
   terminal_value(-> { 24 })
 end
 
-def proc_returning
-  terminal_value(proc { 24 })
+def proc_returning(x, y = 0)
+  return terminal_value(proc { puts "|#{y}|" }) if x.negative?
+
+  tail_call { proc_returning(x - 1, y + 1) }
 end
 
 def bad_return