From e6d5e016f032495fd1f5b918b195befe019bf582 Mon Sep 17 00:00:00 2001
From: Joel Drapper <joel@drapper.me>
Date: Thu, 28 Nov 2024 19:26:49 +0000
Subject: [PATCH] Final type comparisons

---
 lib/literal/types/truthy_type.rb | 21 ++++++++++++++++++---
 lib/literal/types/tuple_type.rb  | 19 ++++++++++++++++++-
 lib/literal/types/union_type.rb  | 23 +++++++++++++++++++----
 test/types.test.rb               | 10 ++++++++++
 4 files changed, 65 insertions(+), 8 deletions(-)

diff --git a/lib/literal/types/truthy_type.rb b/lib/literal/types/truthy_type.rb
index a7cf3ae8..e7026653 100644
--- a/lib/literal/types/truthy_type.rb
+++ b/lib/literal/types/truthy_type.rb
@@ -1,12 +1,27 @@
 # frozen_string_literal: true
 
 # @api private
-module Literal::Types::TruthyType
-	def self.inspect = "_Truthy"
+class Literal::Types::TruthyTypeClass
+	include Literal::Type
 
-	def self.===(value)
+	def inspect
+		"_Truthy"
+	end
+
+	def ===(value)
 		!!value
 	end
 
+	def >=(other)
+		case other
+		when Literal::Types::TruthyType, true
+			true
+		else
+			false
+		end
+	end
+
 	freeze
 end
+
+Literal::Types::TruthyType = Literal::Types::TruthyTypeClass.new.freeze
diff --git a/lib/literal/types/tuple_type.rb b/lib/literal/types/tuple_type.rb
index 6ea36a6d..080715c4 100644
--- a/lib/literal/types/tuple_type.rb
+++ b/lib/literal/types/tuple_type.rb
@@ -2,13 +2,19 @@
 
 # @api private
 class Literal::Types::TupleType
+	include Literal::Type
+
 	def initialize(*types)
 		raise Literal::ArgumentError.new("_Tuple type must have at least one type.") if types.size < 1
 
 		@types = types
 	end
 
-	def inspect = "_Tuple(#{@types.map(&:inspect).join(', ')})"
+	attr_reader :types
+
+	def inspect
+		"_Tuple(#{@types.map(&:inspect).join(', ')})"
+	end
 
 	def ===(value)
 		return false unless Array === value
@@ -39,4 +45,15 @@ def record_literal_type_errors(context)
 			i += 1
 		end
 	end
+
+	def >=(other)
+		case other
+		when Literal::Types::TupleType
+			@types == other.types
+		else
+			false
+		end
+	end
+
+	freeze
 end
diff --git a/lib/literal/types/union_type.rb b/lib/literal/types/union_type.rb
index c0409319..78ad2626 100644
--- a/lib/literal/types/union_type.rb
+++ b/lib/literal/types/union_type.rb
@@ -12,7 +12,11 @@ def initialize(*types)
 		@types.freeze
 	end
 
-	def inspect = "_Union(#{@types.inspect})"
+	attr_reader :types
+
+	def inspect
+		"_Union(#{@types.inspect})"
+	end
 
 	def ===(value)
 		types = @types
@@ -46,9 +50,20 @@ def record_literal_type_errors(ctx)
 		ctx.children.clear if ctx.children.none? { |c| c.children.any? }
 	end
 
-	protected
-
-	attr_reader :types
+	def >=(other)
+		case other
+		when Literal::Types::UnionType
+			other.types.all? do |other_type|
+				@types.any? do |type|
+					Literal.subtype?(type, of: other_type)
+				end
+			end
+		else
+			@types.any? do |type|
+				Literal.subtype?(other, of: type)
+			end
+		end
+	end
 
 	private
 
diff --git a/test/types.test.rb b/test/types.test.rb
index ca25a3af..8170397c 100644
--- a/test/types.test.rb
+++ b/test/types.test.rb
@@ -592,6 +592,10 @@ def expect_type_error(expected:, actual:, message:)
 	refute _Tuple(String, Integer) === ["a"]
 	refute _Tuple(String, Integer) === nil
 
+	assert _Tuple(String, Integer) >= _Tuple(String, Integer)
+	refute _Tuple(String, Integer) >= _Tuple(String, Float)
+	refute _Tuple(String, Integer) >= [String, Float]
+
 	expect_type_error(expected: _Tuple(String, Integer), actual: [1, "a"], message: <<~ERROR)
 		Type mismatch
 
@@ -630,6 +634,12 @@ def expect_type_error(expected:, actual:, message:)
 	refute type === []
 	refute type === nil
 
+	assert _Union(String, Integer) >= _Union(String, Integer)
+	refute _Union(String, Integer) >= _Union(String, Float)
+	assert _Union(String, Integer) >= String
+	refute _Union(String, Integer) >= Numeric
+	assert _Union(String, Numeric) >= Float
+
 	expect_type_error(expected: type, actual: :symbol, message: <<~ERROR)
 		Type mismatch