Python discourages checking the types. But in many cases this may be useful:
Checking constructor arguments. e.g. checking foe Boolean, string, dict etc. If I don't and set the object's members to the arguments it will cause problems later.
Checking functions arguments.
In properties. If someone sets a wrong value or different type, I ...
Duplicate of What is the best (idiomatic) way to check the type of a Python variable?
Sometimes checking of arguments in Python is necessary. e.g. I have a function which accepts either the address of other node in the network as the raw string address or class Node which encapsulates the other node's information.
I use type(0 functi...
The following MSIL code loads a single argument (a string), calls a method, which returns bool, and then returns that bool value. What I don't understand is why it calls stloc.0 to store the method's return value in a local variable, then performs an explicit unconditional control transfer to the very next labeled line (seems unnecessar...
Type systems are often criticised, for being to restrictive, that is limiting programming languages and prohibiting programmers to write interesting programmes.
Chris Smith claims:
We get assurance that the program is correct (in the properties checked by this type checker), but in turn we must reject some interesting programs.
a...
If I have an object, how can I determine its type? (Is there an OCaml equivalent to Java's instanceof operator?)
...
Before I look through my generic data structure for a value's index, I'd like to see if it is even an instance of the type this has been parametrized to. But Eclipse complains when I do this:
@Override
public int indexOf(Object arg0) {
if (!(arg0 instanceof E)) {
return -1;
}
What is the better way to do it?
This is the error mes...
I want the wrapper my_function to be able to receive either a class or class instance, instead of writing two different functions:
>>> from module import MyClass
>>> my_function(MyClass)
True
>>> cls_inst = MyClass()
>>> my_function(cls_inst)
True
the problem is that I don't know in advance which type of classes or class instance...
I know, type checking function arguments is generally frowned upon in Python, but I think I've come up with a situation where it makes sense to do so.
In my project I have an Abstract Base Class Coord, with a subclass Vector, which has more features like rotation, changing magnitude, etc. Lists and tuples of numbers will also return Tr...
Is it possible to do something like this in C#:
public void DoSomething<T>(T t)
{
if (T is MyClass)
{
MyClass mc = (MyClass)t
...
}
else if (T is List<MyClass>)
{
List<MyClass> lmc = (List<MyClass>)t
...
}
}
...
Hi I'm finding a way to enforce runtime type checking or such things in Objective-C on Cocoa.
This is my code sample.
I expected runtime error about wrong assignment to variable 'b'. But it wasn't. Compiled and executed without any error.
#import <Foundation/Foundation.h>
int main (int argc, const char * argv[])
{
NSAutoreleasePoo...
There's a lot of buzz about MooseX::Method::Signatures and even before that, modules such as Params::Validate that are designed to type check every argument to methods or functions. I'm considering using the former for all my future Perl code, both personal and at my place of work. But I'm not sure if it's worth the effort.
I'm thinking...
I have method to which I pass an object. In this method I check it's type and depending on the type I do something with it and return a Long. I have tried every which way I can think of to do this and I always get several compiler errors telling me it expects a certain object but gets another. Can someone please explain to me what I a...
How do I check the type of a Parameter in an Expression Tree (and get the Expression Tree equivalent of a bool if it the right type)? If it were normal code, I would do this:
if(myObj is int)
I see there is a Expression.Convert method but this converts the object instead of just checking its type.
EDIT: I found the answer, you use a ...
Initial situation:
I am working with a proprietary framework (ESRI's ArcGIS Engine) which I want to extend with some new functionality. I've chosen to use extension methods in C# for this.
Shown below are the parts of the framework API that are relevant to this question:
+------------------------+ IGeometry
|...
Using a case construct for type-safe casting is easily done in scala. The following code ensures that square gets only called on objects which have an according type.
class O
class A extends O {
def square(i: Int):Int = { i*i }
}
class B extends O {
def square(d: Double):Double = { d*d }
}
class C extends O {}
def square(o: O) ...
Is there a free tool (some kind of a static checker) that does typedef-based type-checking for a plain C (not C++) and runs on Linux (or any kind of free Unix)? I am aware of a commercial one: PC-lint/FlexeLint. It does exactly what I want, but it's not free and Windows-only. Here is an example from it's manual:
typedef int Count;
typed...