/// <inheritdoc/>
protected override string Convert(Expression <TMethod> expression)
{
var visitor = new DelegateVisitor(this, 1);
visitor.Visit(expression.Body);
return(visitor.Resolution);
}
public void OnWebApiCommand()
{
string input = "namespace Foo { webapi Bar { command void Baz(); } }";
var results = TypesLanguageCompiler.Compile(new[] { new TypesLanguageCompilerInput(input, "") }, Enumerable.Empty<Assembly>());
if (!results.WasSuccessful || !results.HasValue)
Assert.Fail("Expected compilation success.\r\n" + results.Observations.Delimit("\r\n"));
string output = "";
var visitor = new DelegateVisitor { OnWebApiCommand = (cmd, b) => output += cmd.Name };
visitor.Visit(results.Value);
Assert.AreEqual("Baz", output);
}
protected override Expression VisitUnary(UnaryExpression node)
{
if (node.NodeType != ExpressionType.Not)
{
throw new NotSupportedException($"Unary expression {node.NodeType}");
}
var visitor = new DelegateVisitor(_converter, _methodDepth, _objectInstance);
visitor.Visit(node.Operand);
Resolution += $"not ({visitor.Resolution})";
return(node);
}
protected override Expression VisitBinary(BinaryExpression node)
{
var op = node.NodeType switch
{
ExpressionType.Add => "+",
ExpressionType.AndAlso => "and",
ExpressionType.OrElse => "or",
_ => throw new NotSupportedException($"Binary operator {node.NodeType}")
};
var leftVisitor = new DelegateVisitor(_converter, _methodDepth, _objectInstance);
leftVisitor.Visit(node.Left);
var rightVisitor = new DelegateVisitor(_converter, _methodDepth, _objectInstance);
rightVisitor.Visit(node.Right);
Resolution += $"{leftVisitor.Resolution} {op} {rightVisitor.Resolution}";
return(node);
}
protected override Expression VisitMethodCall(MethodCallExpression node)
{
var objectInstance = (node.Object is ConstantExpression constant) ? constant.Value : _objectInstance;
var methodCallFormatter = new Func <string, ReadOnlyCollection <Expression>, string>((name, args) =>
{
var arguments = args.Select(arg =>
{
var argVisitor = new DelegateVisitor(_converter, _methodDepth + 1, objectInstance);
argVisitor.Visit(arg);
return(argVisitor.Resolution);
});
return(string.Format(_converter._methodCallFormat, name, string.Join(", ", arguments)));
});
var supportMethods = new Func <IEnumerable <MethodInfo> >(() => typeof(Installation).GetMethods(BindingFlags.Instance | BindingFlags.Public)
.Where(m => m.GetCustomAttribute <BuiltInSymbolAttribute>() != null));
switch (_methodDepth)
{
case 1:
var supportMethod = supportMethods().FirstOrDefault(m => m.Name == node.Method.Name);
if (supportMethod == null)
{
var handler = BindingSearch.Flags
.Select(f => objectInstance.GetType().GetMethod(node.Method.Name, f))
.FirstOrDefault(m => m != null);
if (handler == null)
{
var msg = $"Only class instance methods may be invoked; {node.Method.Name} is not supported";
throw new NotSupportedException(msg);
}
_converter._visitMethodHandler(node.Method);
}
break;
case 2:
var expandConstantMethod = supportMethods().FirstOrDefault(m => m.Name == nameof(Installation.ExpandConstant));
if (expandConstantMethod == null || node.Method.MetadataToken != expandConstantMethod.MetadataToken)
{
var msg = $"Only the method call {nameof(Installation.ExpandConstant)} is allowed at this depth; {node.Method.Name} is not supported";
throw new NotSupportedException(msg);
}
break;
default:
methodCallFormatter = (name, args) =>
{
var visitor = new InvokingVisitor(objectInstance);
visitor.Visit(node);
return(visitor.Results[0] is string?$"'{visitor.Results[0]}'" : visitor.Results[0].ToString());
};
break;
}
var methodName = node.Method.GetCustomAttribute <AliasAttribute>()?.Name ?? node.Method.Name;
Resolution += methodCallFormatter(methodName, node.Arguments);
return(node);
}
