/prog/ - Null pointers are the billion dollar mistake

Name: Anonymous 2017-02-02 10:34

@davetchepak "What can C# do that F# cannot?"
NullReferenceException :-)

Educating the imperative gorillas about sum types:

https://chadaustin.me/2015/07/sum-types/

Name: Anonymous 2017-02-02 19:58

>>20

C, C++, Java, C#, Python etc still do not[have tagged unions].

enum ShapeKind { Square, Rectangle, Circle };

struct Shape {
    int centerx;
    int centery;
    enum ShapeKind kind;
    union {
        struct { int side; };           /* Square */
        struct { int length, height; }; /* Rectangle */
        struct { int radius; };         /* Circle */
    };
};

int getSquareSide(struct Shape* s) {
    assert(s->kind == Square);
    return s->side;
}

void setSquareSide(struct Shape* s, int side) {
    s->kind = Square;
    s->side = side;
}

/* and so on */

Null pointers are the billion dollar mistake

1 Name: Anonymous 2017-02-02 10:34

21 Name: Anonymous 2017-02-02 19:58

Name: Anonymous 2017-02-02 10:34

Name: Anonymous 2017-02-02 19:58