public override bool Visit(object obj, VisitorContext context)
{
if (obj == null)
{
return(false);
}
var type = obj.GetType();
if (!type.IsGenericType || !type.FullName.StartsWith("System.Tuple`") && !type.FullName.StartsWith("System.ValueTuple`"))
{
return(false);
}
var elemCount = type.GetGenericArguments().Length;
if (elemCount != _expr.Expressions.Count)
{
return(false);
}
for (var i = 0; i < elemCount; i++)
{
var visitor = Visitor.For(_expr.Expressions[i]);
var elem = type.IsValueType
? type.GetField("Item" + (i + 1)).GetValue(obj)
: type.GetProperty("Item" + (i + 1)).GetValue(obj);
if (!visitor.Visit(elem, context))
{
return(false);
}
}
return(true);
}
public override bool Visit(object obj, VisitorContext context)
{
if (obj == null)
{
return(false);
}
var type = obj.GetType();
if (!type.IsArray)
{
return(false);
}
var length = (int)type.GetProperty("Length").GetValue(obj);
var elemGetter = type.GetMethod("Get");
if (_expr.Expressions.Count != length)
{
return(false);
}
for (var i = 0; i < length; i++)
{
var elem = elemGetter.Invoke(obj, new object[] { i });
var visitor = Visitor.For(_expr.Expressions[i]);
if (!visitor.Visit(elem, context))
{
return(false);
}
}
return(true);
}
public override bool Visit(object obj, VisitorContext context)
{
var nameExpr = _expr.Arguments[1] as ConstantExpression;
var name = nameExpr.Value as string;
if (context.CapturedObjects.ContainsKey(name))
{
throw new ArgumentException($"Name '{name}' is already registered in the pattern!");
}
context.CapturedObjects[name] = obj;
return(true);
}
public override bool Visit(object obj, VisitorContext context)
{
if (_expr.Value == null && obj == null)
{
return(true);
}
if (_expr.Value == null || obj == null)
{
return(false);
}
return(_expr.Value.Equals(obj));
}
public Option <TResult> Match(TValue value)
{
var context = new VisitorContext();
var isMatch = Visitor.For(_expr.Body).Visit(value, context);
if (!isMatch)
{
return(Option.None <TResult>());
}
var argExprs = new List <Expression>();
foreach (var arg in _func.Method.GetParameters())
{
if (!context.CapturedObjects.TryGetValue(arg.Name, out var argValue))
{
throw new ArgumentException($"No value was captured for argument '{arg.Name}'!");
}
var argType = arg.ParameterType;
if (argValue == null)
{
if (argType.IsValueType)
{
if (!argType.IsGenericType || argType.GetGenericTypeDefinition() != typeof(Nullable <>))
{
throw new ArgumentException($"Value for argument '{arg.Name}' must be {argType.Name}, found null!");
}
}
}
else
{
var valueType = argValue.GetType();
if (!argType.IsAssignableFrom(valueType))
{
throw new ArgumentException($"Value for argument '{arg.Name}' must be {argType.Name}, found {valueType.Name}!");
}
}
argExprs.Add(Expression.Constant(argValue));
}
var callExpr = Expression.Call(Expression.Constant(_func.Target), _func.Method, argExprs);
var lambdaExpr = Expression.Lambda(callExpr);
var result = lambdaExpr.Compile().DynamicInvoke();
return((Option <TResult>)result);
}
public override bool Visit(object obj, VisitorContext context)
{
if (obj == null)
{
return(false);
}
var type = _expr.Method.GetGenericArguments()[0];
var objType = obj.GetType();
if (!type.IsAssignableFrom(objType))
{
return(false);
}
return(Visitor.For(_expr.Arguments[0]).Visit(obj, context));
}
public override bool Visit(object obj, VisitorContext context)
{
return(true);
}