From db84f7843584e9bc84fa751187952c161c700c0f Mon Sep 17 00:00:00 2001
From: ADAM David Alan Martin <adam@recursive.engineer>
Date: Sat, 18 Nov 2023 02:53:11 -0500
Subject: [PATCH] Started to make a StringMap for fuzzy lookup.

It's not done yet.  But I want to checkpoint it.
---
 Utility/StringMap.h | 67 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 67 insertions(+)
 create mode 100644 Utility/StringMap.h

diff --git a/Utility/StringMap.h b/Utility/StringMap.h
new file mode 100644
index 0000000..1c05a07
--- /dev/null
+++ b/Utility/StringMap.h
@@ -0,0 +1,67 @@
+static_assert( __cplusplus > 2020'99 );
+
+#pragma once
+
+#include <Alepha/Alepha.h>
+
+#include <map>
+#include <string>
+#include <exception>
+#include <stdexcept>
+
+#include <Alepha/Algorithm/string_distance.h>
+
+namespace Alepha::Hydrogen::Utility  ::detail:: StringMap_m
+{
+	inline namespace exports
+	{
+		template< typename Value >
+		class StringMap;
+	}
+
+	template< typename Value >
+	class exports::StringMap
+	{
+		private:
+			std::map< std::string, Value > storage;
+
+			template< typename Self >
+			Value &
+			at_impl( Self &self, const std::string_view key )
+			{
+				if( not storage.contains( key ) )
+				{
+					const auto closest= std::min_element( begin( storage ), end( storage ),
+						[&]( const auto &lhs, const auto &rhs )
+						{
+							const auto l= optimalStringDistance( lhs.first, key );
+							const auto r= optimalStringDistance( rhs.first, key );
+							return l < r;
+						} );
+
+					if( optimalStringDistance( closest.first, key ) < sqrt( key.size() ) )
+					{
+						throw std::out_of_range{ Utility::String() << "The key `" << key << "` could not be found.  Did you mean `"
+								<< closest.first << "`?"  };
+					}
+					throw std::out_of_range{ Utility::String() << "The key `" << key << "` could not be found." };
+				}
+				return storage.at( key );
+			}
+
+		public:
+			Value &at( const std::string_view key ) { return at_impl( *this, key ); }
+			const Value &at( const std::string_view key ) const { return at_impl( *this, key ); }
+
+			bool contains( const std::string_view key ) const { return storage.contains( key ); }
+
+			void insert( const std::string_view key, Value v ) { if( contains( key ) ) storage.insert( { key, std::move( v ) } ); }
+
+			
+	};
+}
+
+namespace Alepha::Hydrogen::Utility::inline exports::inline StringMap_m
+{
+	using namespace detail::StringMap_m::exports;
+}