7 ms·

Have there been any efforts to add real string types and maybe arrays to C? Seems a lot of complications come from the primitive/not existing implementation of

Have there been any efforts to add real string types and maybe arrays to C? Seems a lot of complications come from the primitive/not existing implementation of strings and arrays.

raverbashing 7y ago
It's such a shame that C gets some things like strings so wrong. Writing in C shouldn't have to be so painful, but I guess they were the pioneers in a lot of things and the "high level assembly" idea stuck. (Premature optimization?) Also having objects and method calls, even if it's syntactic sugar deep down, is the best kind of syntactic sugar
- saagarjha 7y ago
  I think you're looking for C++, or maybe Rust.
- compiler-guy 7y ago
  There was nothing "premature" about C's "high-level assembly" idea. It is somewhat archaic now, but C took off because it was so, so much better than normal assembly. If handling strings in plain C is hard, handling them in assembly is 10x as hard.
  - saagarjha 7y ago
    repne scasb disagrees with you :)
    - compiler-guy 7y ago
      As would many other assembly instructions on many other architectures.... and thereby proving my point. :-)
- MadWombat 7y ago
  This is kind of the point of C. It maps directly to the hardware. There are very few decisions the compiler has to make about the code. And it is for that reason that C does not allow for higher level abstractions. On one hand, it is a pain to write. On the other hand, you know exactly what is going on under the hood and nothing is ever going to stop you from shooting yourself in a body part of your choice :)
  - kllrnohj 7y ago
    > This is kind of the point of C. It maps directly to the hardware. No it doesn't. It didn't in the past, it was a high-level abstraction. And it doesn't today, because CPUs don't behave at all like C's defined virtual machine.
    - justinmeiners 7y ago
      > CPUs don't behave at all like C's defined virtual machine What "virtual machine" are you referring to?
      - saagarjha 7y ago
        The one defined in the standard.
      - anticensor 7y ago
        One that ISO 9899 refers to as its abstract machine.
  - ncmncm 7y ago
    C gives the illusion of mapping to the hardware. Hardware manufacturers have moved heaven and earth to help maintain the illusion. It finally got too hard and they had to admit atomics and cores ro the model. The next watershed will be along soon enough, but the ability to present as a C machine has long been the gateway to success or failure of a new hardware architecture. Myriads of arguably superior machine designs have foundered on "but can I code for it in C?"
  - 7y ago
- wahern 7y ago
  C's model is great for implementing complex, efficient data structures. Pointers are an amazing abstraction. But in many respects strings are the antithesis of a data structure, and unsurprisingly C falters hard. The problem is that most programmers don't build data structures; they build Rube Goldberg machines for munging strings, even when they're using low-level languages. Data structures to most programmers are things you import into your Rube Goldberg machine. They don't understand that good programs are made of layers of meticulously crafted, bespoke data structures where the final product is effectively one giant data structure tailored for a particular task, with interfaces to match. It follows that good C programs don't do very much strings munging even if all they do is process text. The text is systematically atomized from the very beginning. The same is true for good programs in any other language.
- klingonopera 7y ago
  "It's such a shame that human beings get some concepts like strings so wrong." - C language Strings are "unnatural" to the binary system, it's a human concept.
saagarjha 7y ago
None that have succeeded, obviously. There are a number of alternative string libraries, though; here's one: https://github.com/antirez/sds https://github.com/antirez/sds. And I'm sure some programmers would suggest C++ as the real "effort to add real string types and maybe arrays to C" ;)
- ncmncm 7y ago
  I, in fact, do suggest C++ as the right answer, where it is not precluded for practical or silly reasons. It is generally quite easy to compile a C program with a C++ compiler, and then the sky's the limit on code improvements. I recommend it, and suggest starting with improvements to memory safety. There is really no excuse for writing a new C program anymore.
  - anmorgan 7y ago
    An 8-bit microcontroller where memory is constrained and all the vendor libraries are written in C, is a good example. Your 32-bit ARM M3/M4 cores are probably crossing that line where the memory cost of using C++ is worth it, but I would say there are still real world reasons to use C. Though I would love to see more microcontroller vendors (or any) support C++ or Rust as part of they HAL libraries, but I think you will still find C to be perfectly viable for the low cost microcontroller application.
    - ncmncm 7y ago
      If it's too small for C++, it's also too small for C. Arduino is 8 bits, and it's C++ from here to the horizon. On ARM it is no contest, at any size. Funny little $.10 PICcy things may not have a C++ compiler available. Then, the C compiler is better than asm, if you can fit. Otherwise, no excuse.
      - anmorgan 7y ago
        On Arduino, from my experience, it is easy to run into memory constraints, especially when using dynamically allocated memory like strings. And I'm taking about both the flash memory for code and the ram for data, stack, and heap. I don't think C is always a win, but to say to never use for new projects seems overly biased. Why is your opinion about C so strong? I am curious.
scarface74 7y ago
Sure, Microsoft has added plenty of them over the years... - BSTR - CString - bstr_t - basic_string - and a bunch of typedefs...
xenadu02 7y ago
In theory the standards committee could decide to add _array_ref to the language (or some variation on pointer+length). &myArray[10] could create an _array_ref where sizeof works against it and attempts to take a slice past the end of the array abort. I can even imagine compatibility shims like __attribute__((array_ref(1,2))) similar to printf-style format decorators that tell the compiler how to map function parameters of pointer+length to _array_ref. There are many technical details to be worked out and choices to be made but there is no fundamental intractable problem preventing it. We'd have incremental adoption over many years. Maybe some legacy code would never be updated. The primary blocker is getting the committee members to admit this is a problem that should be solved. That is difficult enough here on HN, where some people are still arguing that C is fine as-is and we just need to invent better programmers / better tools. Ultimately C's lack of better string support comes from its lack of better array support. That comes from a certain subset of the programmer community that believes the status-quo is fine and isn't interested in such changes.
- pornel 7y ago
  It would be so nice if C had "fat pointers" (ptr+len). It's such an obvious small change that would have a massive impact on usability and safety. Unfortunately, C is dead. Microsoft thinks C is dead, and intentionally keeps their compiler awful. Even ISO WG doesn't seem to have a vision for C's future and have been rearranging deck chairs for the last 20 years.
  - ncmncm 7y ago
    We already know C's future. The people using old C are self-selected as those who like it the way it is. They accepted atomics because of new hardware. The place to ask for new, better stuff is at the C++ desk, and it has lots already.
  - klingonopera 7y ago
    Well, it has. You just said so, it's (ptr+len). ...it's the philosophy of the C language: There's minimal bloat on the upside, but you have to know what you're doing and how to be able get it on the downside.
user5994461 7y ago
If you mean string as in text string, it's not done and I doubt it could ever be achieved in C++. It's too complicated because of unicode and string encoding aspects. The new type wouldn't be usable either, because it would have to be converted down to another representation all the time when calling functions and libraries that are not aware of it. Think of C string to C++ string to boost string to whatever. I think the closest usable thing is QString if you are using Qt.
- kevin_thibedeau 7y ago
  Length counted, sliceable arrays would be sufficient to upgrade C. D has these.
CameronNemo 7y ago
As for arrays, I frequently find implementations of hash maps and linked lists that come with macros for iteration, appending, etc. libnih is the first to come to mind (GPLv2 only), but I also know that the LXC project has some similar code floating around in there... probably LGPLv2+.

Have there been any efforts to add real string types and maybe arrays to C? Seems a lot of complications come from the primitive/not existing implementation of strings and arrays.

raverbashing 7y ago

It's such a shame that C gets some things like strings so wrong. Writing in C shouldn't have to be so painful, but I guess they were the pioneers in a lot of things and the "high level assembly" idea stuck. (Premature optimization?) Also having objects and method calls, even if it's syntactic sugar deep down, is the best kind of syntactic sugar

saagarjha 7y ago
I think you're looking for C++, or maybe Rust.
compiler-guy 7y ago
There was nothing "premature" about C's "high-level assembly" idea. It is somewhat archaic now, but C took off because it was so, so much better than normal assembly. If handling strings in plain C is hard, handling them in assembly is 10x as hard.
- saagarjha 7y ago
  repne scasb disagrees with you :)
  - compiler-guy 7y ago
    As would many other assembly instructions on many other architectures.... and thereby proving my point. :-)
MadWombat 7y ago
This is kind of the point of C. It maps directly to the hardware. There are very few decisions the compiler has to make about the code. And it is for that reason that C does not allow for higher level abstractions. On one hand, it is a pain to write. On the other hand, you know exactly what is going on under the hood and nothing is ever going to stop you from shooting yourself in a body part of your choice :)
- kllrnohj 7y ago
  > This is kind of the point of C. It maps directly to the hardware. No it doesn't. It didn't in the past, it was a high-level abstraction. And it doesn't today, because CPUs don't behave at all like C's defined virtual machine.
  - justinmeiners 7y ago
    > CPUs don't behave at all like C's defined virtual machine What "virtual machine" are you referring to?
    - saagarjha 7y ago
      The one defined in the standard.
    - anticensor 7y ago
      One that ISO 9899 refers to as its abstract machine.
- ncmncm 7y ago
  C gives the illusion of mapping to the hardware. Hardware manufacturers have moved heaven and earth to help maintain the illusion. It finally got too hard and they had to admit atomics and cores ro the model. The next watershed will be along soon enough, but the ability to present as a C machine has long been the gateway to success or failure of a new hardware architecture. Myriads of arguably superior machine designs have foundered on "but can I code for it in C?"
- 7y ago
wahern 7y ago
C's model is great for implementing complex, efficient data structures. Pointers are an amazing abstraction. But in many respects strings are the antithesis of a data structure, and unsurprisingly C falters hard. The problem is that most programmers don't build data structures; they build Rube Goldberg machines for munging strings, even when they're using low-level languages. Data structures to most programmers are things you import into your Rube Goldberg machine. They don't understand that good programs are made of layers of meticulously crafted, bespoke data structures where the final product is effectively one giant data structure tailored for a particular task, with interfaces to match. It follows that good C programs don't do very much strings munging even if all they do is process text. The text is systematically atomized from the very beginning. The same is true for good programs in any other language.
klingonopera 7y ago
"It's such a shame that human beings get some concepts like strings so wrong." - C language Strings are "unnatural" to the binary system, it's a human concept.

saagarjha 7y ago

None that have succeeded, obviously. There are a number of alternative string libraries, though; here's one: https://github.com/antirez/sds https://github.com/antirez/sds. And I'm sure some programmers would suggest C++ as the real "effort to add real string types and maybe arrays to C" ;)

ncmncm 7y ago
I, in fact, do suggest C++ as the right answer, where it is not precluded for practical or silly reasons. It is generally quite easy to compile a C program with a C++ compiler, and then the sky's the limit on code improvements. I recommend it, and suggest starting with improvements to memory safety. There is really no excuse for writing a new C program anymore.
- anmorgan 7y ago
  An 8-bit microcontroller where memory is constrained and all the vendor libraries are written in C, is a good example. Your 32-bit ARM M3/M4 cores are probably crossing that line where the memory cost of using C++ is worth it, but I would say there are still real world reasons to use C. Though I would love to see more microcontroller vendors (or any) support C++ or Rust as part of they HAL libraries, but I think you will still find C to be perfectly viable for the low cost microcontroller application.
  - ncmncm 7y ago
    If it's too small for C++, it's also too small for C. Arduino is 8 bits, and it's C++ from here to the horizon. On ARM it is no contest, at any size. Funny little $.10 PICcy things may not have a C++ compiler available. Then, the C compiler is better than asm, if you can fit. Otherwise, no excuse.
    - anmorgan 7y ago
      On Arduino, from my experience, it is easy to run into memory constraints, especially when using dynamically allocated memory like strings. And I'm taking about both the flash memory for code and the ram for data, stack, and heap. I don't think C is always a win, but to say to never use for new projects seems overly biased. Why is your opinion about C so strong? I am curious.

scarface74 7y ago

Sure, Microsoft has added plenty of them over the years... - BSTR - CString - bstr_t - basic_string - and a bunch of typedefs...

xenadu02 7y ago

In theory the standards committee could decide to add _array_ref to the language (or some variation on pointer+length). &myArray[10] could create an _array_ref where sizeof works against it and attempts to take a slice past the end of the array abort. I can even imagine compatibility shims like __attribute__((array_ref(1,2))) similar to printf-style format decorators that tell the compiler how to map function parameters of pointer+length to _array_ref. There are many technical details to be worked out and choices to be made but there is no fundamental intractable problem preventing it. We'd have incremental adoption over many years. Maybe some legacy code would never be updated. The primary blocker is getting the committee members to admit this is a problem that should be solved. That is difficult enough here on HN, where some people are still arguing that C is fine as-is and we just need to invent better programmers / better tools. Ultimately C's lack of better string support comes from its lack of better array support. That comes from a certain subset of the programmer community that believes the status-quo is fine and isn't interested in such changes.

pornel 7y ago
It would be so nice if C had "fat pointers" (ptr+len). It's such an obvious small change that would have a massive impact on usability and safety. Unfortunately, C is dead. Microsoft thinks C is dead, and intentionally keeps their compiler awful. Even ISO WG doesn't seem to have a vision for C's future and have been rearranging deck chairs for the last 20 years.
- ncmncm 7y ago
  We already know C's future. The people using old C are self-selected as those who like it the way it is. They accepted atomics because of new hardware. The place to ask for new, better stuff is at the C++ desk, and it has lots already.
- klingonopera 7y ago
  Well, it has. You just said so, it's (ptr+len). ...it's the philosophy of the C language: There's minimal bloat on the upside, but you have to know what you're doing and how to be able get it on the downside.

user5994461 7y ago

If you mean string as in text string, it's not done and I doubt it could ever be achieved in C++. It's too complicated because of unicode and string encoding aspects. The new type wouldn't be usable either, because it would have to be converted down to another representation all the time when calling functions and libraries that are not aware of it. Think of C string to C++ string to boost string to whatever. I think the closest usable thing is QString if you are using Qt.

kevin_thibedeau 7y ago
Length counted, sliceable arrays would be sufficient to upgrade C. D has these.

CameronNemo 7y ago

As for arrays, I frequently find implementations of hash maps and linked lists that come with macros for iteration, appending, etc. libnih is the first to come to mind (GPLv2 only), but I also know that the LXC project has some similar code floating around in there... probably LGPLv2+.