ircd::json: Improve constexpr-hashed-name related and uniform overloads for non-tuples.

include/ircd/json.h

@@ -50,6 +50,11 @@ namespace ircd::json
 	enum type type(const string_view &, std::nothrow_t);
 	string_view reflect(const enum type &);
 
+	using name_hash_t = size_t;
+	constexpr name_hash_t name_hash(const char *const name, const size_t len = 0);
+	constexpr name_hash_t name_hash(const string_view &name);
+	constexpr name_hash_t operator ""_(const char *const name, const size_t len);
+
 	/// Higher order type beyond a string to cleanly delimit multiple keys.
 	using path = std::initializer_list<string_view>;
 	std::ostream &operator<<(std::ostream &, const path &);
@@ -78,6 +83,7 @@ namespace ircd::json
 
 namespace ircd
 {
+	using json::operator ""_;
 	using json::operator<<;
 }
 
@@ -188,3 +194,21 @@ ircd::json::operator<<(std::ostream &s, const path &p)
 
 	return s;
 }
+
+constexpr ircd::json::name_hash_t
+ircd::json::operator ""_(const char *const text, const size_t len)
+{
+	return name_hash(text, len);
+}
+
+constexpr ircd::json::name_hash_t
+ircd::json::name_hash(const string_view &name)
+{
+	return ircd::hash(name);
+}
+
+constexpr ircd::json::name_hash_t
+ircd::json::name_hash(const char *const name, const size_t len)
+{
+	return ircd::hash(name);
+}

include/ircd/json/object.h

@@ -25,6 +25,9 @@
 namespace ircd::json
 {
 	struct object;
+
+	template<name_hash_t key, class T = string_view> T at(const object &);
+	template<name_hash_t key, class T = string_view> T get(const object &, const T &def = {});
 }
 
 /// Lightweight interface to a JSON object string.
@@ -81,6 +84,7 @@ struct ircd::json::object
 	const_iterator end() const;
 	const_iterator begin() const;
 	const_iterator find(const string_view &key) const;
+	const_iterator find(const name_hash_t &key) const;
 
 	// util
 	size_t count() const;
@@ -214,6 +218,25 @@ catch(const bad_lex_cast &e)
 	                 typeid(T).name());
 }
 
+template<ircd::json::name_hash_t key,
+         class T>
+T
+ircd::json::at(const object &object)
+try
+{
+	const auto it(object.find(key));
+	if(it == end(object))
+		throw not_found("[key hash] '%zu'", key);
+
+	return lex_cast<T>(it->second);
+}
+catch(const bad_lex_cast &e)
+{
+	throw type_error("[key hash] '%zu' must cast to type %s",
+	                 key,
+	                 typeid(T).name());
+}
+
 template<class T>
 T
 ircd::json::object::at(const string_view &key)
@@ -273,6 +296,25 @@ catch(const bad_lex_cast &e)
 	return def;
 }
 
+template<ircd::json::name_hash_t key,
+         class T>
+ircd::string_view
+ircd::json::get(const object &object,
+                const T &def)
+try
+{
+	const auto it{object.find(key)};
+	if(it == end(object))
+		return def;
+
+	const string_view sv{it->second};
+	return !sv.empty()? lex_cast<T>(sv) : def;
+}
+catch(const bad_lex_cast &e)
+{
+	return def;
+}
+
 template<class T>
 T
 ircd::json::object::get(const string_view &key,
@@ -329,6 +371,17 @@ const
 	return find(key) != end();
 }
 
+inline ircd::json::object::const_iterator
+ircd::json::object::find(const name_hash_t &key)
+const
+{
+	return std::find_if(begin(), end(), [&key]
+	(const auto &member)
+	{
+		return name_hash(member.first) == key;
+	});
+}
+
 inline ircd::json::object::const_iterator
 ircd::json::object::find(const string_view &key)
 const

include/ircd/json/tuple.h

@@ -22,19 +22,6 @@
 #pragma once
 #define HAVE_IRCD_JSON_TUPLE_H
 
-namespace ircd::json
-{
-	constexpr size_t operator ""_(const char *const text, const size_t len)
-	{
-		return ircd::hash(text);
-	}
-}
-
-namespace ircd
-{
-	using json::operator ""_;
-}
-
 namespace ircd {
 namespace json {
 
@@ -169,7 +156,7 @@ template<class tuple,
 constexpr typename std::enable_if<i < size<tuple>(), size_t>::type
 indexof()
 {
-	const auto equal
+	constexpr auto equal
 	{
 		ircd::hash(key<tuple, i>()) == hash
 	};
@@ -190,7 +177,7 @@ template<class tuple,
 constexpr typename std::enable_if<i < size<tuple>(), size_t>::type
 indexof(const char *const &name)
 {
-	const auto equal
+	constexpr auto equal
 	{
 		_constexpr_equal(key<tuple, i>(), name)
 	};