diff --git a/demo.srd b/demo.srd
index 9cc6023..7576a85 100644
--- a/demo.srd
+++ b/demo.srd
@@ -31,8 +31,8 @@
 (fn dof-init ()
 	# Sampler used for the inputs
 	(sampler dof-sampler
-		(sampling clamp-edge)
 		(mipmaps no)
+		(wrapping clamp-edge)
 		(sampling linear)
 		(lod 0 0)	
 	)
diff --git a/opast.cc b/opast.cc
index 5ac8adf..abc23e0 100644
--- a/opast.cc
+++ b/opast.cc
@@ -27,19 +27,30 @@ T_RootNode& A_Node::root( ) const noexcept
 			const_cast< A_Node* >( node ) );
 }
 
+
+/*= T_InstrListNode ==========================================================*/
+
+T_InstrListNode::T_InstrListNode(
+		A_Node& parent ) noexcept
+	: A_Node( ILIST , &parent )
+{ }
+
+
 /*= A_FuncNode ===============================================================*/
 
 A_FuncNode::A_FuncNode(
 		const bool isInit ,
 		T_RootNode* const root ) noexcept
 	: A_Node( isInit ? DECL_INIT : DECL_FRAME , root ) ,
-		name_( isInit ? "*init*" : "*frame*" )
+		name_( isInit ? "*init*" : "*frame*" ) ,
+		instructions_( *this )
 { }
 
 A_FuncNode::A_FuncNode(
 		T_String const& name ,
 		T_RootNode* const root ) noexcept
-	: A_Node( DECL_FN , root ) , name_( name )
+	: A_Node( DECL_FN , root ) , name_( name ) ,
+		instructions_( *this )
 { }
 
 
@@ -112,19 +123,119 @@ T_Optional< T_SRDLocation > T_FuncNode::addArgument(
 }
 
 
+/*= T_PipelineInstrNode ======================================================*/
+
+T_PipelineInstrNode::T_PipelineInstrNode(
+		T_InstrListNode& parent ,
+		T_SRDToken const& idToken ) noexcept
+	: A_InstructionNode( OP_PIPELINE , parent ) ,
+		id_( idToken.stringValue( ) ) ,
+		idLocation_( idToken.location( ) )
+{ }
+
+T_PipelineInstrNode::T_PipelineInstrNode(
+		T_InstrListNode& parent ) noexcept
+	: A_InstructionNode( OP_PIPELINE , parent ) ,
+		id_( "*invalid*" ) ,
+		idLocation_{ }
+{ }
+
+T_Optional< T_SRDLocation > T_PipelineInstrNode::addProgram(
+		T_SRDToken const& pidToken ) noexcept
+{
+	T_String const& name( pidToken.stringValue( ) );
+	const auto pIndex( pids_.indexOf( name ) );
+	if ( pIndex != -1 ) {
+		return pidLocations_[ pIndex ];
+	}
+	pids_.add( name );
+	pidLocations_.add( pidToken.location( ) );
+	return {};
+}
+
+
+/*= T_ProfileInstrNode =======================================================*/
+
+T_ProfileInstrNode::T_ProfileInstrNode(
+		T_InstrListNode& parent ,
+		T_String const& text ) noexcept
+	: A_InstructionNode( OP_PROFILE , parent ) ,
+		text_( text ) ,
+		instructions_( *this )
+{ }
+
+
+/*= T_ProgramInstrNode =======================================================*/
+
+T_ProgramInstrNode::T_ProgramInstrNode(
+		T_InstrListNode& parent ,
+		T_SRDToken const& idToken ,
+		T_SRDToken const& pathToken ) noexcept
+	: A_InstructionNode( OP_PROGRAM , parent ) ,
+		id_( idToken.stringValue( ) ) ,
+		idLocation_( idToken.location( ) ) ,
+		path_( pathToken.stringValue( ) ) ,
+		pathLocation_( pathToken.location( ) )
+{ }
+
+
 /*= T_Parser =================================================================*/
 
 namespace {
 
 struct T_ParserImpl_
 {
+	enum class E_InstrType {
+		IF ,
+		PIPELINE ,
+		PROFILE ,
+		PROGRAM ,
+	};
+
+	const T_KeyValueTable< T_String , E_InstrType > instrMap{ ([]() {
+		T_KeyValueTable< T_String , E_InstrType > temp;
+		const auto add{ [&temp]( char const* name , E_InstrType it ) {
+			temp.add( T_String::Pooled( name ) , it );
+		} };
+
+		add( "if" , E_InstrType::IF );
+		add( "pipeline" , E_InstrType::PIPELINE );
+		add( "profiling" , E_InstrType::PROFILE );
+		add( "program" , E_InstrType::PROGRAM );
+
+		return temp;
+	})( ) };
+
+	// ---------------------------------------------------------------------
+
 	T_OwnPtr< T_RootNode >& root;
 	T_Array< T_SRDError >& errors;
 
 	T_ParserImpl_( T_Array< T_SRDError >* errors ,
 			T_OwnPtr< T_RootNode >* root ) noexcept;
 
+	// ---------------------------------------------------------------------
+
 	void parseFunction( T_SRDList const& funcList ) noexcept;
+	void parseFunctionArguments(
+			T_FuncNode& function ,
+			T_SRDToken const& argsToken ) noexcept;
+	void parseInstructions(
+			T_InstrListNode& instructions ,
+			T_SRDList const& input ,
+			uint32_t start ) noexcept;
+
+	// ---------------------------------------------------------------------
+
+	void parsePipelineInstruction(
+			T_InstrListNode& instructions ,
+			T_SRDList const& input ) noexcept;
+	void parseProfileInstruction(
+			T_InstrListNode& instructions ,
+			T_SRDList const& input ) noexcept;
+	void parseProgramInstruction(
+			T_InstrListNode& instructions ,
+			T_SRDList const& input ) noexcept;
 };
 
 T_ParserImpl_::T_ParserImpl_(
@@ -160,7 +271,8 @@ void T_ParserImpl_::parseFunction(
 		}
 
 		fn = NewOwned< T_FuncNode >( funcList[ 1 ].stringValue( ) , *root );
-		// TODO parseFunctionArguments( funcList[ 2 ] );
+		parseFunctionArguments( dynamic_cast< T_FuncNode& >( *fn ) ,
+				funcList[ 2 ] );
 	} else {
 		fn = NewOwned< T_SpecialFuncNode >( ftw == "init" , *root );
 	}
@@ -185,8 +297,181 @@ void T_ParserImpl_::parseFunction(
 		errors.addNew( std::move( esb ) , fw.location( ) );
 	}
 
-	// TODO parseInstructions( fn->instructions , funcList ,
-	// 			ftw == "fn" ? 3 : 1 );
+	parseInstructions( af.function.instructions( ) , funcList , ftw == "fn" ? 3 : 1 );
+}
+
+void T_ParserImpl_::parseFunctionArguments(
+		T_FuncNode& function ,
+		T_SRDToken const& argsToken ) noexcept
+{
+	if ( argsToken.type( ) != E_SRDTokenType::LIST ) {
+		errors.addNew( "arguments list expected" , argsToken.location( ) );
+		return;
+	}
+	for ( auto const& token : argsToken.list( ) ) {
+		if ( token.type( ) != E_SRDTokenType::WORD ) {
+			errors.addNew( "argument name expected" , token.location( ) );
+			continue;
+		}
+
+		const auto rv( function.addArgument( token ) );
+		if ( rv.present( ) ) {
+			T_StringBuilder esb;
+			esb << "duplicate argument '" << token.stringValue( )
+				<< "'; previous declaration: " << *rv.target( );
+			errors.addNew( std::move( esb ) , token.location( ) );
+		}
+	}
+}
+
+void T_ParserImpl_::parseInstructions(
+		T_InstrListNode& instructions ,
+		T_SRDList const& input ,
+		const uint32_t start ) noexcept
+{
+	for ( auto iter( input.begin( ) + start ) ; iter.valid( ) ; iter ++ ) {
+		T_SRDToken const& itok( *iter );
+		if ( itok.type( ) != E_SRDTokenType::LIST ) {
+			errors.addNew( "instruction expected" , itok.location( ) );
+			continue;
+		}
+
+		T_SRDList const& ilist( itok.list( ) );
+		if ( ilist.empty( ) ) {
+			errors.addNew( "instruction expected" , itok.location( ) );
+			continue;
+		}
+
+		T_SRDToken const& iname( ilist[ 0 ] );
+		if ( iname.type( ) != E_SRDTokenType::WORD ) {
+			errors.addNew( "instruction name expected" , iname.location( ) );
+			continue;
+		}
+
+		T_String const& iword( iname.stringValue( ) );
+		if ( !instrMap.contains( iword ) ) {
+			errors.addNew( "unknown instruction" , iname.location( ) );
+			continue;
+		}
+
+		switch ( *instrMap.get( iword ) ) {
+			case E_InstrType::PIPELINE:
+				parsePipelineInstruction( instructions , ilist );
+				break;
+			case E_InstrType::PROFILE:
+				parseProfileInstruction( instructions , ilist );
+				break;
+			case E_InstrType::PROGRAM:
+				parseProgramInstruction( instructions , ilist );
+				break;
+		}
+	}
+}
+
+/*----------------------------------------------------------------------------*/
+
+void T_ParserImpl_::parsePipelineInstruction(
+		T_InstrListNode& instructions ,
+		T_SRDList const& input ) noexcept
+{
+	if ( input.size( ) < 3 ) {
+		errors.addNew( "identifier and program identifiers expected" ,
+				input[ 0 ].location( ) );
+		return;
+	}
+
+	const bool validId( input[ 1 ].type( ) == E_SRDTokenType::WORD );
+	if ( !validId ) {
+		errors.addNew( "pipeline identifier expected" , input[ 1 ].location( ) );
+	}
+
+	T_PipelineInstrNode& pipeline{ ([&instructions,&input,validId]( ) -> T_PipelineInstrNode& {
+		if ( validId ) {
+			return instructions.add< T_PipelineInstrNode >( input[ 0 ] );
+		}
+		return instructions.add< T_PipelineInstrNode >( );
+	})() };
+	pipeline.location( ) = input[ 0 ].location( );
+
+	const auto nMax{ std::min( input.size( ) , 8u ) };
+	for ( auto i = 2u ; i < nMax ; i ++ ) {
+		T_SRDToken const& tok( input[ i ] );
+		if ( tok.type( ) != E_SRDTokenType::WORD ) {
+			errors.addNew( "program identifier expected" ,
+					tok.location( ) );
+			continue;
+		}
+		const auto dup( pipeline.addProgram( tok ) );
+		if ( dup.present( ) ) {
+			T_StringBuilder esb;
+			esb << "duplicate program identifier; previous use: "
+				<< *dup.target( );
+			errors.addNew( std::move( esb ) , tok.location( ) );
+		}
+	}
+
+	if ( input.size( ) > 8 ) {
+		errors.addNew( "too many arguments" , input[ 8 ].location( ) );
+	}
+}
+
+/*----------------------------------------------------------------------------*/
+
+void T_ParserImpl_::parseProfileInstruction(
+		T_InstrListNode& instructions ,
+		T_SRDList const& input ) noexcept
+{
+	const bool hasEnough( input.size( ) < 2 );
+	if ( hasEnough || !input[ 1 ].isText( ) ) {
+		errors.addNew( "profiling section name expected" ,
+				hasEnough ? input[ 1 ].location( ) : T_SRDLocation{} );
+		if ( !hasEnough ) {
+			return;
+		}
+	}
+
+	const T_String text( input[ 1 ].isText( ) ? input[ 1 ].stringValue( ) : "*invalid*" );
+	T_ProfileInstrNode& profile{ instructions.add< T_ProfileInstrNode >( text ) };
+	profile.location( ) = input[ 0 ].location( );
+	parseInstructions( profile.instructions( ) , input , 2 );
+}
+
+/*----------------------------------------------------------------------------*/
+
+void T_ParserImpl_::parseProgramInstruction(
+		T_InstrListNode& instructions ,
+		T_SRDList const& input ) noexcept
+{
+	bool ok{ true };
+	if ( input.size( ) == 1 ) {
+		errors.addNew( "identifier and program name required" ,
+				input[ 0 ].location( ) );
+		return;
+	}
+	if ( input[ 1 ].type( ) != E_SRDTokenType::WORD ) {
+		errors.addNew( "identifier (word) expected" , input[ 1 ].location( ) );
+		ok = false;
+	}
+	if ( input.size( ) == 2 ) {
+		errors.addNew( "program name required" , input[ 0 ].location( ) );
+		return;
+	}
+	if ( !input[ 2 ].isText( ) ) {
+		errors.addNew( "program name (string or word) expected" ,
+				input[ 2 ].location( ) );
+		ok = false;
+	}
+
+	if ( input.size( ) > 3 ) {
+		errors.addNew( "too many arguments" , input[ 3 ].location( ) );
+	}
+	if ( !ok ) {
+		return;
+	}
+
+	T_ProgramInstrNode& program{ instructions.add< T_ProgramInstrNode >(
+				input[ 1 ] , input[ 2 ] ) };
+	program.location( ) = input[ 0 ].location( );
 }
 
 } // namespace
@@ -208,10 +493,25 @@ bool T_Parser::parse(
 		if ( t.type( ) == E_SRDTokenType::LIST && t.list( ).size( ) > 0 ) {
 			p< T_ParserImpl_ >( ).parseFunction( t.list( ) );
 		} else {
-			errors_.addNew( "Function or special block expected" ,
+			errors_.addNew( "function, init or frame list expected" ,
 					t.location( ) );
 		}
 	}
 
+	if ( errors_.empty( ) ) {
+		T_SRDLocation loc( ([&input]() {
+			if ( input.size( ) != 0 ) {
+				return T_SRDLocation( input[ 0 ].location( ).source( ) , 1 , 1 );
+			}
+			return T_SRDLocation{};
+		})( ));
+		if ( !rootNode_->hasInit( ) ) {
+			errors_.addNew( "no initialisation block" , loc );
+		}
+		if ( !rootNode_->hasFrame( ) ) {
+			errors_.addNew( "no initialisation block" , loc );
+		}
+	}
+
 	return errors_.empty( );
 }
diff --git a/opast.hh b/opast.hh
index f0ac73f..d059db1 100644
--- a/opast.hh
+++ b/opast.hh
@@ -16,20 +16,24 @@ class A_Node
 {
     public:
 	enum E_Type {
-		ROOT ,
+		ROOT ,		// Root node
+		ILIST ,		// Instruction list
 		//
-		DECL_INIT ,
-		DECL_FRAME ,
-		DECL_FN ,
+		DECL_INIT ,	// Initialisation block
+		DECL_FRAME ,	// Frame block
+		DECL_FN ,	// Function
 		//
-		OP_SET ,
+		OP_PIPELINE ,	// Shader pipeline declaration
+		OP_PROFILE ,	// Profiling block
+		OP_PROGRAM ,	// Shader program declaration
+		OP_SET ,	// Set instruction
 		//
-		EXPR_ADD ,
-		EXPR_MUL ,
-		EXPR_SUB ,
-		EXPR_DIV ,
-		EXPR_VAR ,
-		EXPR_CONST ,
+		EXPR_ADD ,	// Binary ops: add
+		EXPR_MUL ,	// Binary ops: mul
+		EXPR_SUB ,	// Binary ops: sub
+		EXPR_DIV ,	// Binary ops: div
+		EXPR_VAR ,	// Variable access
+		EXPR_CONST ,	// Numeric constant
 	};
 
     private:
@@ -60,11 +64,49 @@ class A_Node
 
 /*----------------------------------------------------------------------------*/
 
+class A_InstructionNode : public A_Node
+{
+    protected:
+	A_InstructionNode( E_Type type ,
+			A_Node& parent ) noexcept
+		: A_Node( type , &parent )
+	{}
+};
+
+// Nodes that store lists of instructions
+class T_InstrListNode : public A_Node
+{
+    private:
+	T_Array< T_OwnPtr< A_InstructionNode > > instructions_;
+
+    public:
+	T_InstrListNode( A_Node& parent ) noexcept;
+
+	template<
+		typename IType ,
+		typename... ArgTypes
+	> IType& add( ArgTypes&&... args );
+};
+
+template<
+	typename IType ,
+	typename... ArgTypes
+> inline IType& T_InstrListNode::add(
+		ArgTypes&&... args )
+{
+	instructions_.add( NewOwned< IType >( *this ,
+			std::forward< ArgTypes >( args ) ... ) );
+	return (IType&) *instructions_.last( );
+}
+
+/*----------------------------------------------------------------------------*/
+
 // Function-like nodes
 class A_FuncNode : public A_Node
 {
     private:
 	T_String name_;
+	T_InstrListNode instructions_;
 
     protected:
 	// For init or frame entry points.
@@ -80,6 +122,11 @@ class A_FuncNode : public A_Node
     public:
 	T_String const& name( ) const noexcept
 		{ return name_; }
+
+	T_InstrListNode& instructions( ) noexcept
+		{ return instructions_; }
+	T_InstrListNode const& instructions( ) const noexcept
+		{ return instructions_; }
 };
 
 // Root node, keeps track of the whole tree and related data (function table,
@@ -92,6 +139,8 @@ class T_RootNode : public A_Node
     public:
 	T_RootNode( ) noexcept;
 
+	// ---------------------------------------------------------------------
+
 	// Return type for addFunction. We'll always return a reference to a
 	// function node (which may or may not be the same as the initial one,
 	// if there were duplicates), and we'll return the location of the
@@ -117,6 +166,15 @@ class T_RootNode : public A_Node
 	// entry will be added to the table instead).
 	T_AddFunctionResult addFunction(
 			T_OwnPtr< A_FuncNode >& function ) noexcept;
+
+	// ---------------------------------------------------------------------
+
+	bool hasFunction( T_String const& name ) noexcept
+		{ return functions_.contains( name ); }
+	bool hasInit( ) noexcept
+		{ return hasFunction( "*init*" ); }
+	bool hasFrame( ) noexcept
+		{ return hasFunction( "*frame*" ); }
 };
 
 /*----------------------------------------------------------------------------*/
@@ -147,7 +205,78 @@ class T_FuncNode : public A_FuncNode
 			T_SRDToken const& token ) noexcept;
 };
 
-/*----------------------------------------------------------------------------*/
+/*============================================================================*/
+
+// Pipeline declaration instruction
+class T_PipelineInstrNode : public A_InstructionNode
+{
+    private:
+	T_String id_;
+	T_SRDLocation idLocation_;
+	T_StaticArray< T_String , 6 > pids_;
+	T_StaticArray< T_SRDLocation , 6 > pidLocations_;
+
+    public:
+	T_PipelineInstrNode(
+			T_InstrListNode& parent ,
+			T_SRDToken const& idToken ) noexcept;
+	explicit T_PipelineInstrNode(
+			T_InstrListNode& parent ) noexcept;
+
+	// Add a program identifier. The token is assumed to be a valid word,
+	// and the list of programs is assumed not to be full. If the identifer
+	// is already in the pipeline's list, the location of the first
+	// occurrence will be returned.
+	T_Optional< T_SRDLocation > addProgram(
+			T_SRDToken const& pidToken ) noexcept;
+
+	uint32_t size( ) const noexcept
+		{ return pids_.size( ); }
+
+	T_String const& program( const uint32_t index ) const noexcept
+		{ return pids_[ index ]; }
+	T_SRDLocation const& pLocation( const uint32_t index ) const noexcept
+		{ return pidLocations_[ index ]; }
+};
+
+// Profiling instruction
+class T_ProfileInstrNode : public A_InstructionNode
+{
+    private:
+	T_String text_;
+	T_InstrListNode instructions_;
+
+    public:
+	T_ProfileInstrNode(
+			T_InstrListNode& parent ,
+			T_String const& text ) noexcept;
+
+	T_String const& text( ) const
+		{ return text_; }
+
+	T_InstrListNode& instructions( ) noexcept
+		{ return instructions_; }
+	T_InstrListNode const& instructions( ) const noexcept
+		{ return instructions_; }
+};
+
+// Program loader instruction
+class T_ProgramInstrNode : public A_InstructionNode
+{
+    private:
+	T_String id_;
+	T_SRDLocation idLocation_;
+	T_String path_;
+	T_SRDLocation pathLocation_;
+
+    public:
+	T_ProgramInstrNode(
+			T_InstrListNode& parent ,
+			T_SRDToken const& idToken ,
+			T_SRDToken const& pathToken ) noexcept;
+};
+
+/*============================================================================*/
 
 class T_Parser : public A_PrivateImplementation
 {