FromParseTreeToBackend <TSymbol> (IParseTree <TSymbol> parseTree) where TSymbol : ISymbol <TSymbol>
{
// build AST
var ast = new ASTBuilder().BuildAST(parseTree);
// apply visitors
ast.Accept(new NameResolutionVisitor());
ast.Accept(new TypeCheckVisitor());
ast.FillInNestedUseFlag();
ast.Accept(new FunctionLocalVisitor()); // create backend function objects
// get all functions from AST
IEnumerable <FunctionDefinitionNode> funcList = ast.GetAllFunctionDefinitions();
// for each function -> extract controlflow (controlflow graph = expression graph)
// each vertex of this graph holds (AST) ExpressionNode
// during this phase - substitute nested function definition with empty BlockExpression
IEnumerable <Tuple <FunctionDefinitionNode, ControlFlowGraph> > funcCFGs = funcList.Select(
t => Tuple.Create(t, new ControlFlowExtractor().Extract(t.Body))
);
// for each function - extract side effects
funcCFGs = funcCFGs.Select(
t => Tuple.Create(t.Item1, new SideEffectExtractor().Extract(t.Item2))
);
// finally build and return list of functions (backend tree representation is inside function)
return(funcCFGs.Select(
t => BackendBuilder.BuildBackendFunction(t.Item1, t.Item2)
));
}