Meh, I think NULL is fine in C. It's an extra, valid state to represent pointers at no cost. Unlike the more hand holdy languages, it's quite rare for a pointer in C to have the ability to be NULL since, more often than not, it's pointing at something known. It's actually quite rare to see NULL checks unless it's API code or something like that. I can see this being more of a problem in a managed language where anything can be NULL at any time.

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bvrmn 6 hours ago | parent | next [-]

NULL as a concept is fine. Inability to declare something as non-null is not.

There is a huge gap between developer expectation "it's pointing at something known" and hard reality confirmed by zillions of CVE. That's the reason optionality is prevalent in modern languages and type checkers (python, typescript), nowdays even Java has sane non-nullable types.

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kelnos 7 hours ago | parent | prev | next [-]

> to represent pointers at no cost

I wouldn't call "cause of bugs and security issues" "no cost".

> it's quite rare for a pointer in C to have the ability to be NULL

As a C programmer for more than 25 years, that is the exact opposite of my experience.

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none_to_remain 6 hours ago | parent | prev | next [-]

Struct foo has various members, including a bar*. But a foo may or may not be associated with a bar. If there's no associated bar, the bar* pointer is NULL. Seen and done this all the time

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UqWBcuFx6NV4r 6 hours ago | parent | prev | next [-]

This precise mindset is why the world has suffered for decades (wrt security/integrity/availability) at the hands of what can only be described as an industry led by completely unjustified male confidence. Why are there still people fighting the “it’s not that bad, guys! you’ve just got to be a good developer like ME!” fight?

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IgorPartola 6 hours ago | parent [-]

Is None OK in Python?

NULL in C just doesn’t belong at the end of a string. But IMO having a “there is no value here” designation is not a bad thing.

	▲	none_to_remain 6 hours ago \| parent \| next [-]
		I think you're mixing up the NULL pointer and the NULL (sometimes NUL) character.
	▲	jibal 3 hours ago \| parent \| prev [-]
		Python is interpreted so None is always tested for and will throw an exception if used in the wrong context. This is quite different from a SEGVIO. > But IMO having a “there is no value here” designation is not a bad thing. Sure ... if it's done via the type system so that errors are caught at compile time. There's a reason that modern languages all either do this or are moving towards doing it. (And a reason that C programmers have no idea what we're talking about when we refer to type systems.) > NULL in C just doesn’t belong at the end of a string. Different discussion. (And NUL, not NULL.)

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XorNot 6 hours ago | parent | prev [-]

The problem with let's get rid of NULL is that it's a real, required state. The vast majority of computing is actually not binary: any real input generally has at least 3 possible states: not set, true and false.

In practice really 4 because "indeterminate" is a reasonable error condition you'd like to know about.

And it keeps increasing anyway: e.g. not set has subcategories: not set due to lack of user input, not set because we're loading state from the backend etc.

NULL is the first expression of that basic problem: it's definitely not enough to eliminate NULL because the first thing which happens is your non pointer default value takes it's place.

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lambdaone 5 hours ago | parent | next [-]

What you are describing is option types, which are an entirely valid and very useful construct that helps make programs more rather than less reliable. But you need proper language type system support and compile-time enforcement to make it work, and C does neither of those.

	▲	bnolsen 4 hours ago \| parent [-]
		C++ and rust make these optionals ugly. Zig does it right. Zig also forbids null pointers and requires use of optionals.

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5 hours ago | parent | prev [-]

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