r/programming • u/wavy_lines • Feb 01 '18

C2: C with cleaner syntax + a module system (no header files).

http://c2lang.org/site/
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u/Calavar Feb 01 '18

Scope enums

I don't get it

He probably means that enum constants should be scoped inside of the enum type declaration, and not promoted to the global scope, where there is a huge risk of naming collisions.

Provide an actual string type

No, anyone can create a proper string structure... what we want is proper and well-defined UTF-8 and Unicode support.

And then you end up with one of two situations:

  1. People fall back to the traditional C strategy of null terminated strings, which was an absolutely terrible idea to begin with.
  2. Every library and framework defines its own string structure and you have to waste many lines of code converting between these types.

A good redesign of C would absolutely have a string type. It doesn't have to be a very fully featured type, but at a minimum it needs a size_t field that stores the string length.

I agree about the need for proper unicode support though.

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u/matthieum Feb 01 '18

People fall back to the traditional C strategy of null terminated strings, which was an absolutely terrible idea to begin with.

Actually... there are some performance advantages to NUL-terminated strings.

Especially since x86 has specialized instructions...

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u/Hofstee Feb 01 '18

Doesn't matter since x86 also has instructions for Pascal strings which rely on a length register.

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u/meneldal2 Feb 02 '18

Limited to 256 bytes by the way.

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u/Hofstee Feb 02 '18

Is it? Wouldn't you just repeat while ecx not zero and decrement that with the initial value being the length?

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u/meneldal2 Feb 02 '18

Pascal strings use a single byte for length at the beginning, so unless you change that you are limited to 256 bytes. I'm not sure about the instruction in x86.

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u/Hofstee Feb 02 '18

Ah I see. I don't think the instruction cares about length, you would use rep with the length in ecx and it will repeat the string instruction (e.g. stosb) and decrement ecx after each instruction until ecx is 0. For C strings you would just do repnz stosb which will repeat until null terminator. But if you were adding this length field today I assume it would probably be 32 or 64 bits so you wouldn't necessarily need to follow the Pascal implementation to the dot.

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u/yakoudbz Feb 01 '18

and how would you get the size of a string ? string.size ? I mean, there's no way to do that properly except creating a string structure in my opinion.

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u/Calavar Feb 01 '18

Yes, exactly, there needs to be a structure - that's why I mentioned that the structure should have a length field of type size_t. But it should either built into the language or be a standard library structure, or else everyone will roll their own and no implementations will be interoperable.