diff --git a/shaders.cc b/shaders.cc
index 2d4e08b..4e45f37 100644
--- a/shaders.cc
+++ b/shaders.cc
@@ -3,134 +3,139 @@
 
 
 namespace {
-	const std::regex PreprocDirective_( "^\\s*//!\\s*([a-z]+(\\s+([^\\s]+))*)\\s*$" );
 
-	const std::map< std::string , E_ShaderInput > InputTypes_( ([] {
-		std::map< std::string , E_ShaderInput > t;
-		t.emplace( "chunk" , E_ShaderInput::CHUNK );
-		t.emplace( "library" , E_ShaderInput::LIBRARY );
-		t.emplace( "lib" , E_ShaderInput::LIBRARY );
-		t.emplace( "vertex" , E_ShaderInput::VERTEX );
-		t.emplace( "fragment" , E_ShaderInput::FRAGMENT );
-		return t;
-	})());
+const std::regex PreprocDirective_( "^\\s*//!\\s*([a-z]+(\\s+([^\\s]+))*)\\s*$" );
 
+const std::map< std::string , E_ShaderInput > InputTypes_( ([] {
+	std::map< std::string , E_ShaderInput > t;
+	t.emplace( "chunk" , E_ShaderInput::CHUNK );
+	t.emplace( "library" , E_ShaderInput::LIBRARY );
+	t.emplace( "lib" , E_ShaderInput::LIBRARY );
+	t.emplace( "vertex" , E_ShaderInput::VERTEX );
+	t.emplace( "fragment" , E_ShaderInput::FRAGMENT );
+	return t;
+})());
 
-	struct T_InputReader_
-	{
-		using T_Tokens_ = std::vector< std::string >;
+/*============================================================================*/
 
-		FILE* const file;
-		T_ShaderInput& input;
-		uint32_t line{ 0 };
+// Input reader state and functions, used when loading a source file
+struct T_InputReader_
+{
+	using T_Tokens_ = std::vector< std::string >;
 
-		char* buffer{ nullptr };
-		ssize_t readCount;
+	FILE* const file;
+	T_ShaderInput& input;
+	uint32_t line{ 0 };
 
-		std::string accumulator{ };
-		uint32_t accumLines{ 0 };
+	char* buffer{ nullptr };
+	ssize_t readCount;
 
-		T_InputReader_( __rd__ FILE* const file ,
-				__rw__ T_ShaderInput& input )
-			: file( file ) , input( input )
-		{ }
-		~T_InputReader_( );
+	std::string accumulator{ };
+	uint32_t accumLines{ 0 };
 
-		void read( );
-		void nl( );
-		void addAccumulated( );
-		void handleDirective(
-				__rd__ T_Tokens_ const& tokens );
-		void error( __rd__ std::string const& err );
-	};
+	T_InputReader_( __rd__ FILE* const file ,
+			__rw__ T_ShaderInput& input )
+		: file( file ) , input( input )
+	{ }
+	~T_InputReader_( );
 
-	T_InputReader_::~T_InputReader_( )
-	{
-		if ( buffer ) {
-			free( buffer );
-		}
-		fclose( file );
+	void read( );
+	void nl( );
+	void addAccumulated( );
+	void handleDirective(
+			__rd__ T_Tokens_ const& tokens );
+	void error( __rd__ std::string const& err );
+};
+
+/*----------------------------------------------------------------------------*/
+
+T_InputReader_::~T_InputReader_( )
+{
+	if ( buffer ) {
+		free( buffer );
 	}
+	fclose( file );
+}
 
-	void T_InputReader_::read( )
-	{
-		size_t bsz( 0 );
-		while ( ( readCount = getline( &buffer , &bsz , file ) ) != -1 ) {
-			line ++;
-			std::cmatch match;
-			if ( std::regex_match( buffer , match , PreprocDirective_ ) ) {
-				const T_Tokens_ tokens( ([](std::string const& a) {
-					using stri = std::istream_iterator< std::string >;
-					std::istringstream iss( a );
-					return T_Tokens_{ stri( iss ) , stri( ) };
-				})( match[ 1 ].str( ) ) );
-				assert( tokens.size( ) >= 1 );
-				handleDirective( tokens );
-			} else {
-				accumulator += buffer;
-				accumLines ++;
-			}
+void T_InputReader_::read( )
+{
+	size_t bsz( 0 );
+	while ( ( readCount = getline( &buffer , &bsz , file ) ) != -1 ) {
+		line ++;
+		std::cmatch match;
+		if ( std::regex_match( buffer , match , PreprocDirective_ ) ) {
+			const T_Tokens_ tokens( ([](std::string const& a) {
+				using stri = std::istream_iterator< std::string >;
+				std::istringstream iss( a );
+				return T_Tokens_{ stri( iss ) , stri( ) };
+			})( match[ 1 ].str( ) ) );
+			assert( tokens.size( ) >= 1 );
+			handleDirective( tokens );
+		} else {
+			accumulator += buffer;
+			accumLines ++;
+		}
+	}
+	addAccumulated( );
+}
+
+void T_InputReader_::nl( )
+{
+	accumLines ++;
+	accumulator += '\n';
+}
+
+void T_InputReader_::addAccumulated( )
+{
+	if ( accumLines ) {
+		auto& ck( input.chunks );
+		ck.emplace_back( E_ShaderInputChunk::CODE ,
+				std::move( accumulator ) , accumLines );
+		accumulator = {};
+		accumLines = 0;
+	}
+}
+
+void T_InputReader_::handleDirective(
+		__rd__ T_Tokens_ const& tokens )
+{
+	auto const& directive( tokens[ 0 ] );
+
+	if ( directive == "include" ) {
+		if ( tokens.size( ) != 2 ) {
+			nl( );
+			error( "invalid arguments" );
+			return;
 		}
 		addAccumulated( );
-	}
+		auto& ck( input.chunks );
+		ck.emplace_back( E_ShaderInputChunk::INCLUDE , tokens[ 1 ] , 1 );
 
-	void T_InputReader_::nl( )
-	{
-		accumLines ++;
-		accumulator += '\n';
-	}
-
-	void T_InputReader_::addAccumulated( )
-	{
-		if ( accumLines ) {
-			auto& ck( input.chunks );
-			ck.emplace_back( E_ShaderInputChunk::CODE ,
-					std::move( accumulator ) , accumLines );
-			accumulator = {};
-			accumLines = 0;
+	} else if ( directive == "type" ) {
+		nl( );
+		if ( tokens.size( ) != 2 ) {
+			error( "invalid arguments" );
+			return;
 		}
-	}
-
-	void T_InputReader_::handleDirective(
-			__rd__ T_Tokens_ const& tokens )
-	{
-		auto const& directive( tokens[ 0 ] );
-
-		if ( directive == "include" ) {
-			if ( tokens.size( ) != 2 ) {
-				nl( );
-				error( "invalid arguments" );
-				return;
-			}
-			addAccumulated( );
-			auto& ck( input.chunks );
-			ck.emplace_back( E_ShaderInputChunk::INCLUDE , tokens[ 1 ] , 1 );
-
-		} else if ( directive == "type" ) {
-			nl( );
-			if ( tokens.size( ) != 2 ) {
-				error( "invalid arguments" );
-				return;
-			}
-			auto pos( InputTypes_.find( tokens[ 1 ] ) );
-			if ( pos == InputTypes_.end( ) ) {
-				error( "unknown type" );
-			} else {
-				input.type = pos->second;
-			}
-
+		auto pos( InputTypes_.find( tokens[ 1 ] ) );
+		if ( pos == InputTypes_.end( ) ) {
+			error( "unknown type" );
 		} else {
-			nl( );
-			error( "unknown directive" );
+			input.type = pos->second;
 		}
-	}
 
-	void T_InputReader_::error(
-			__rd__ std::string const& err )
-	{
-		input.errors.push_back( T_ShaderInputError{
-				line , err } );
+	} else {
+		nl( );
+		error( "unknown directive" );
 	}
+}
+
+void T_InputReader_::error(
+		__rd__ std::string const& err )
+{
+	input.errors.push_back( T_ShaderInputError{
+			line , err } );
+}
 
 } // namespace