Trivia preservation

include/toml++/impl/array.hpp

@@ -7,6 +7,8 @@
 #include "std_utility.hpp"
 #include "std_vector.hpp"
 #include "std_initializer_list.hpp"
+#include "preprocessor.hpp"
+#include "trivia_piece.hpp"
 #include "value.hpp"
 #include "make_node.hpp"
 #include "header_start.hpp"
@@ -290,6 +292,7 @@ TOML_NAMESPACE_START
 		using vector_iterator		= typename vector_type::iterator;
 		using const_vector_iterator = typename vector_type::const_iterator;
 		vector_type elems_;
+		optional<std::vector<trivia_piece>> inner_trailing_trivia_;
 
 		TOML_NODISCARD_CTOR
 		TOML_EXPORTED_MEMBER_FUNCTION
@@ -404,6 +407,20 @@ TOML_NAMESPACE_START
 		TOML_EXPORTED_MEMBER_FUNCTION
 		array& operator=(array&& rhs) noexcept;
 
+		/// \brief	Gets the inner trailing trivia.
+		TOML_CONST_INLINE_GETTER
+		const optional<std::vector<trivia_piece>> inner_trailing_trivia() const noexcept
+		{
+			return inner_trailing_trivia_;
+		}
+
+		/// \brief	Sets the inner trailing trivia.
+		TOML_EXPORTED_MEMBER_FUNCTION
+		void set_inner_trailing_trivia(optional<std::vector<trivia_piece>> trivia) noexcept
+		{
+			inner_trailing_trivia_ = trivia;
+		}
+
 		/// \name Type checks
 		/// @{
 

include/toml++/impl/array.inl

@@ -65,7 +65,8 @@ TOML_NAMESPACE_START
 
 	TOML_EXTERNAL_LINKAGE
 	array::array(const array& other) //
-		: node(other)
+		: node(other),
+		  inner_trailing_trivia_(other.inner_trailing_trivia_)
 	{
 		elems_.reserve(other.elems_.size());
 		for (const auto& elem : other)
@@ -79,7 +80,8 @@ TOML_NAMESPACE_START
 	TOML_EXTERNAL_LINKAGE
 	array::array(array && other) noexcept //
 		: node(std::move(other)),
-		  elems_(std::move(other.elems_))
+		  elems_(std::move(other.elems_)),
+		  inner_trailing_trivia_(other.inner_trailing_trivia_)
 	{
 #if TOML_LIFETIME_HOOKS
 		TOML_ARRAY_CREATED;
@@ -96,6 +98,7 @@ TOML_NAMESPACE_START
 			elems_.reserve(rhs.elems_.size());
 			for (const auto& elem : rhs)
 				elems_.emplace_back(impl::make_node(elem));
+			inner_trailing_trivia_ = rhs.inner_trailing_trivia_;
 		}
 		return *this;
 	}
@@ -107,6 +110,7 @@ TOML_NAMESPACE_START
 		{
 			node::operator=(std::move(rhs));
 			elems_ = std::move(rhs.elems_);
+			inner_trailing_trivia_ = rhs.inner_trailing_trivia_;
 		}
 		return *this;
 	}

include/toml++/impl/date_time.hpp

@@ -7,6 +7,7 @@
 #include "forward_declarations.hpp"
 #include "print_to_stream.hpp"
 #include "header_start.hpp"
+#include "std_optional.hpp"
 
 TOML_NAMESPACE_START
 {

include/toml++/impl/formatter.hpp

@@ -130,6 +130,12 @@ TOML_IMPL_NAMESPACE_START
 			return !!(config_.flags & format_flags::terse_key_value_pairs);
 		}
 
+		TOML_PURE_INLINE_GETTER
+		bool preserve_source_trivia() const noexcept
+		{
+			return !!(config_.flags & format_flags::preserve_source_trivia);
+		}
+
 		TOML_EXPORTED_MEMBER_FUNCTION
 		void attach(std::ostream& stream) noexcept;
 

include/toml++/impl/forward_declarations.hpp

@@ -343,6 +343,9 @@ TOML_NAMESPACE_START // abi namespace
 
 		/// \brief Avoids the use of whitespace around key-value pairs.
 		terse_key_value_pairs = (1ull << 12),
+
+		/// \brief Preserves trivia of nodes that have it (i.e. were passed with collect_trivia enabled).
+		preserve_source_trivia = (1ull << 13)
 	};
 	TOML_MAKE_FLAGS(format_flags);
 

include/toml++/impl/key.hpp

@@ -4,6 +4,8 @@
 // SPDX-License-Identifier: MIT
 #pragma once
 
+#include "std_vector.hpp"
+#include "trivia_piece.hpp"
 #include "source_region.hpp"
 #include "std_utility.hpp"
 #include "print_to_stream.hpp"
@@ -33,6 +35,8 @@ TOML_NAMESPACE_START
 	  private:
 		std::string key_;
 		source_region source_;
+		std::optional<std::vector<trivia_piece>> leading_trivia_;
+		std::optional<std::vector<trivia_piece>> trailing_trivia_;
 
 	  public:
 		/// \brief	Default constructor.
@@ -41,44 +45,74 @@ TOML_NAMESPACE_START
 
 		/// \brief	Constructs a key from a string view and source region.
 		TOML_NODISCARD_CTOR
-		explicit key(std::string_view k, source_region&& src = {}) //
+		explicit key(std::string_view k,
+					 source_region&& src					   = {},
+					 optional<std::vector<trivia_piece>> leading_trivia  = optional<std::vector<trivia_piece>>(),
+					 optional<std::vector<trivia_piece>> trailing_trivia = optional<std::vector<trivia_piece>>()) //
 			: key_{ k },
-			  source_{ std::move(src) }
+			  source_{ std::move(src) },
+			  leading_trivia_(leading_trivia),
+			  trailing_trivia_(trailing_trivia)
 		{}
 
 		/// \brief	Constructs a key from a string view and source region.
 		TOML_NODISCARD_CTOR
-		explicit key(std::string_view k, const source_region& src) //
+		explicit key(std::string_view k,
+					 const source_region& src,
+					 optional<std::vector<trivia_piece>> leading_trivia  = optional<std::vector<trivia_piece>>(),
+					 optional<std::vector<trivia_piece>> trailing_trivia = optional<std::vector<trivia_piece>>()) //
 			: key_{ k },
-			  source_{ src }
+			  source_{ src },
+			  leading_trivia_(leading_trivia),
+			  trailing_trivia_(trailing_trivia)
 		{}
 
 		/// \brief	Constructs a key from a string and source region.
 		TOML_NODISCARD_CTOR
-		explicit key(std::string&& k, source_region&& src = {}) noexcept //
+		explicit key(std::string&& k,
+					 source_region&& src					   = {},
+					 optional<std::vector<trivia_piece>> leading_trivia  = optional<std::vector<trivia_piece>>(),
+					 optional<std::vector<trivia_piece>> trailing_trivia = optional<std::vector<trivia_piece>>()) noexcept //
 			: key_{ std::move(k) },
-			  source_{ std::move(src) }
+			  source_{ std::move(src) },
+			  leading_trivia_(leading_trivia),
+			  trailing_trivia_(trailing_trivia)
 		{}
 
 		/// \brief	Constructs a key from a string and source region.
 		TOML_NODISCARD_CTOR
-		explicit key(std::string&& k, const source_region& src) noexcept //
+		explicit key(std::string&& k,
+					 const source_region& src,
+					 optional<std::vector<trivia_piece>> leading_trivia  = optional<std::vector<trivia_piece>>(),
+					 optional<std::vector<trivia_piece>> trailing_trivia = optional<std::vector<trivia_piece>>()) noexcept //
 			: key_{ std::move(k) },
-			  source_{ src }
+			  source_{ src },
+			  leading_trivia_(leading_trivia),
+			  trailing_trivia_(trailing_trivia)
 		{}
 
 		/// \brief	Constructs a key from a c-string and source region.
 		TOML_NODISCARD_CTOR
-		explicit key(const char* k, source_region&& src = {}) //
+		explicit key(const char* k,
+					 source_region&& src					   = {},
+					 optional<std::vector<trivia_piece>> leading_trivia  = optional<std::vector<trivia_piece>>(),
+					 optional<std::vector<trivia_piece>> trailing_trivia = optional<std::vector<trivia_piece>>()) //
 			: key_{ k },
-			  source_{ std::move(src) }
+			  source_{ std::move(src) },
+			  leading_trivia_(leading_trivia),
+			  trailing_trivia_(trailing_trivia)
 		{}
 
 		/// \brief	Constructs a key from a c-string view and source region.
 		TOML_NODISCARD_CTOR
-		explicit key(const char* k, const source_region& src) //
+		explicit key(const char* k,
+					 const source_region& src,
+					 optional<std::vector<trivia_piece>> leading_trivia  = optional<std::vector<trivia_piece>>(),
+					 optional<std::vector<trivia_piece>> trailing_trivia = optional<std::vector<trivia_piece>>()) //
 			: key_{ k },
-			  source_{ src }
+			  source_{ src },
+			  leading_trivia_(leading_trivia),
+			  trailing_trivia_(trailing_trivia)
 		{}
 
 #if TOML_ENABLE_WINDOWS_COMPAT
@@ -87,18 +121,28 @@ TOML_NAMESPACE_START
 		///
 		/// \availability This constructor is only available when #TOML_ENABLE_WINDOWS_COMPAT is enabled.
 		TOML_NODISCARD_CTOR
-		explicit key(std::wstring_view k, source_region&& src = {}) //
+		explicit key(std::wstring_view k,
+					 source_region&& src					   = {},
+					 optional<std::vector<trivia_piece>> leading_trivia  = optional<std::vector<trivia_piece>>(),
+					 optional<std::vector<trivia_piece>> trailing_trivia = optional<std::vector<trivia_piece>>()) //
 			: key_{ impl::narrow(k) },
-			  source_{ std::move(src) }
+			  source_{ std::move(src) },
+			  leading_trivia_(leading_trivia),
+			  trailing_trivia_(trailing_trivia)
 		{}
 
 		/// \brief	Constructs a key from a wide string and source region.
 		///
 		/// \availability This constructor is only available when #TOML_ENABLE_WINDOWS_COMPAT is enabled.
 		TOML_NODISCARD_CTOR
-		explicit key(std::wstring_view k, const source_region& src) //
+		explicit key(std::wstring_view k,
+					 const source_region& src,
+					 optional<std::vector<trivia_piece>> leading_trivia  = optional<std::vector<trivia_piece>>(),
+					 optional<std::vector<trivia_piece>> trailing_trivia = optional<std::vector<trivia_piece>>()) //
 			: key_{ impl::narrow(k) },
-			  source_{ src }
+			  source_{ src },
+			  leading_trivia_(leading_trivia),
+			  trailing_trivia_(trailing_trivia)
 		{}
 
 #endif
@@ -155,6 +199,23 @@ TOML_NAMESPACE_START
 
 		/// @}
 
+		/// \name Metadata
+		/// @{
+
+		/// \brief	Returns the key's leading trivia.
+		optional<std::vector<trivia_piece>> leading_trivia() const noexcept
+		{
+			return leading_trivia_;
+		}
+
+		/// \brief	Returns the key's trailing trivia.
+		optional<std::vector<trivia_piece>> trailing_trivia() const noexcept
+		{
+			return trailing_trivia_;
+		}
+
+		/// @}
+
 		/// \name Equality and Comparison
 		/// \attention These operations only compare the underlying strings; source regions are ignored for the purposes of all comparison!
 		/// @{
@@ -332,4 +393,10 @@ TOML_NAMESPACE_START
 }
 TOML_NAMESPACE_END;
 
+template<> struct std::hash<toml::key> {
+    std::size_t operator()(toml::key const& k) const noexcept {
+        return std::hash<std::string_view>{}(k.str());
+    }
+};
+
 #include "header_end.hpp"

include/toml++/impl/node.hpp

@@ -5,9 +5,12 @@
 #pragma once
 
 #include "std_utility.hpp"
+#include "std_vector.hpp"
 #include "forward_declarations.hpp"
 #include "source_region.hpp"
 #include "header_start.hpp"
+#include "preprocessor.hpp"
+#include "trivia_piece.hpp"
 
 TOML_NAMESPACE_START
 {
@@ -22,6 +25,8 @@ TOML_NAMESPACE_START
 
 		friend class TOML_PARSER_TYPENAME;
 		source_region source_{};
+		std::optional<std::vector<trivia_piece>> leading_trivia_;
+		std::optional<std::vector<trivia_piece>> trailing_trivia_;
 
 		template <typename T>
 		TOML_NODISCARD
@@ -728,6 +733,34 @@ TOML_NAMESPACE_START
 
 		/// @}
 
+		/// \brief	Returns the leading trivia attached to this node.
+		TOML_PURE_INLINE_GETTER
+		const optional<std::vector<trivia_piece>>& leading_trivia() const noexcept
+		{
+			return leading_trivia_;
+		}
+
+		/// \brief	Returns the trailing trivia attached to this node.
+		TOML_PURE_INLINE_GETTER
+		const optional<std::vector<trivia_piece>>& trailing_trivia() const noexcept
+		{
+			return trailing_trivia_;
+		}
+
+		/// \brief	Sets the leading trivia attached to this node.
+		TOML_EXPORTED_MEMBER_FUNCTION
+		void set_leading_trivia(optional<std::vector<trivia_piece>> leading_trivia) noexcept
+		{
+			leading_trivia_ = leading_trivia;
+		}
+
+		/// \brief	Sets the trailing trivia attached to this node.
+		TOML_EXPORTED_MEMBER_FUNCTION
+		void set_trailing_trivia(optional<std::vector<trivia_piece>> trailing_trivia) noexcept
+		{
+			trailing_trivia_ = trailing_trivia;
+		}
+
 	  private:
 		/// \cond
 

include/toml++/impl/node.inl

@@ -29,25 +29,31 @@ TOML_NAMESPACE_START
 
 	TOML_EXTERNAL_LINKAGE
 	node::node(node && other) noexcept //
-		: source_{ std::exchange(other.source_, {}) }
+		: source_{ std::exchange(other.source_, {}) },
+		  leading_trivia_(other.leading_trivia_),
+		  trailing_trivia_(other.trailing_trivia_)
 	{}
 
 	TOML_EXTERNAL_LINKAGE
-	node::node(const node& /*other*/) noexcept
+	node::node(const node& other) noexcept
+		: leading_trivia_(other.leading_trivia_),
+		  trailing_trivia_(other.trailing_trivia_)
 	{
 		// does not copy source information - this is not an error
 		//
 		// see https://github.com/marzer/tomlplusplus/issues/49#issuecomment-665089577
 	}
 
 	TOML_EXTERNAL_LINKAGE
-	node& node::operator=(const node& /*rhs*/) noexcept
+	node& node::operator=(const node& rhs) noexcept
 	{
 		// does not copy source information - this is not an error
 		//
 		// see https://github.com/marzer/tomlplusplus/issues/49#issuecomment-665089577
 
 		source_ = {};
+		leading_trivia_ = rhs.leading_trivia_;
+		trailing_trivia_ = rhs.trailing_trivia_;
 		return *this;
 	}
 
@@ -56,6 +62,8 @@ TOML_NAMESPACE_START
 	{
 		if (&rhs != this)
 			source_ = std::exchange(rhs.source_, {});
+		leading_trivia_ = rhs.leading_trivia_;
+		trailing_trivia_ = rhs.trailing_trivia_;
 		return *this;
 	}