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People often regard C code as inherently ugly because of nasty coding styles that were prevalent in the 80s and 90s – all local variables declared at the top of

People often regard C code as inherently ugly because of nasty coding styles that were prevalent in the 80s and 90s – all local variables declared at the top of functions, lots of global variables, "space saving" indentation and often no whitespace between operators, bad separation of concerns. C can actually be a decent "high-level" language if you conform to a more modern style of programming. Codebases like Git and Nginx demonstrate that this is possible.

adrianratnapala 10y ago
I generally agree with you, but C even at it's nicest is not "high level" except in the trivial sense of being having a recursive grammar (which assembly doesn't have). The whole advantage of C is that it is a powerful, nice, and portable way to express roughly the same things you would otherwise express in assembly. Most of the really nasty undefined behaviour of modern compilers comes from forgetting this.
- bluetomcat 10y ago
  C is actually "high-level" in most aspects and we tend to forget that because of newer languages with lots of bells and whistles. C gives you a lot over assembly: functions with (mostly) no need to worry about calling conventions, automatic variables instead of dealing with registers and stack frame offsets, expression-oriented syntax that facilitates nesting of many operations within a single statement, structured programming support instead of scattered jumps and a rudimentary type system around values, pointers, arrays and structs. Nothing fancy, but it means that the language can be compiled in a straightforward manner without any runtime support and a programmer can easily have a complete mental model of it.
  - pjmlp 10y ago
    Compared with languages like Ada, Modula-2, Turbo Pascal, Mesa/Cedar, Algol, PL/I, C is what we used to call a middle level language in those days. And Algol, PL/I and their respective variants are around 10 years older than C.
  - adrianratnapala 10y ago
    Indeed. I don't want to give the impression that C is just assembly. It gives all the advantages you name, and they are very important. But I still say that C is a way of talking about same things you want to talk about in assembly, albeit while automating some tedious but important things like register allocation. You are still commanding the computer at a low level: still telling it which byte to put on which IO port or memory location. Of course you can build higher level abstractions on this -- but only to a point. C compilers go wrong when they imagine a C program lives in such a higher level of abstraction -- whereas the other languages thrive on defining such abstract machines.
    - colanderman 10y ago
      But you can't actually directly address I/O ports in C, and directly addressing memory (via pointer arithmetic which oversteps the bounds of an object, or which puns the type of an object) invokes undefined behavior. Both those things depend on details of the underlying architecture, ABI, and operating system, and are abstracted away in C.
pjmlp 10y ago
> People often regard C code as inherently ugly because of nasty coding styles that were prevalent in the 80s and 90s Those code styles as still prevalent in 2016, speaking from the experience of occasionally having to look into how people write C code to integrate into Java, .NET, Python, Ruby at the enterprise level, which just stresses my point of view about the language. Specially since outside HN bubble many don't even know what a static analyser or code review are all about.
- josefx 10y ago
  Saw Hungarian notation used by two distinct developers in 2016. One of them freshly graduated and otherwise a halfway decent programmer. As far as I could tell both used it just as wrong as most developers did almost two decades ago. Bad styles find a way to live on.
marios 10y ago
What is wrong with declaring local variables at the top of functions ?
- titzer 10y ago
  Because you generally want to put declarations close to their uses to minimize their scope? Reduce cognitive load and improve local reasoning?
  - wtbob 10y ago
    But in general functions shouldn't really be all that long anyway (if they are, break 'em up!). I kinda like declaring my variables all at the top — I think it looks nice & clean.
    - bluetomcat 10y ago
      Even in short functions, "declare it when it's needed" makes your program follow a data-flow style and enables you to use const more, since in many cases the initialization is the only assignment that you do to that variable.
  - dllthomas 10y ago
    While the parent technically said "at the start of functions", at least C89 (I don't remember about K&R) allowed declarations at the start of any block. This is not incompatible with minimizing scope - just introduce more blocks. And in fact, introducing a block to bound the scope of a variable allows a smaller scope than simply declaring it halfway through a function, as you can also end it early.
- majewsky 10y ago
  If you declare a variable as `const`, you have to initialize it during declaration. So you have to place the declaration exactly where the value expression becomes available.
  - bluetomcat 10y ago

adrianratnapala 10y ago

I generally agree with you, but C even at it's nicest is not "high level" except in the trivial sense of being having a recursive grammar (which assembly doesn't have). The whole advantage of C is that it is a powerful, nice, and portable way to express roughly the same things you would otherwise express in assembly. Most of the really nasty undefined behaviour of modern compilers comes from forgetting this.

bluetomcat 10y ago
C is actually "high-level" in most aspects and we tend to forget that because of newer languages with lots of bells and whistles. C gives you a lot over assembly: functions with (mostly) no need to worry about calling conventions, automatic variables instead of dealing with registers and stack frame offsets, expression-oriented syntax that facilitates nesting of many operations within a single statement, structured programming support instead of scattered jumps and a rudimentary type system around values, pointers, arrays and structs. Nothing fancy, but it means that the language can be compiled in a straightforward manner without any runtime support and a programmer can easily have a complete mental model of it.
- pjmlp 10y ago
  Compared with languages like Ada, Modula-2, Turbo Pascal, Mesa/Cedar, Algol, PL/I, C is what we used to call a middle level language in those days. And Algol, PL/I and their respective variants are around 10 years older than C.
- adrianratnapala 10y ago
  Indeed. I don't want to give the impression that C is just assembly. It gives all the advantages you name, and they are very important. But I still say that C is a way of talking about same things you want to talk about in assembly, albeit while automating some tedious but important things like register allocation. You are still commanding the computer at a low level: still telling it which byte to put on which IO port or memory location. Of course you can build higher level abstractions on this -- but only to a point. C compilers go wrong when they imagine a C program lives in such a higher level of abstraction -- whereas the other languages thrive on defining such abstract machines.
  - colanderman 10y ago
    But you can't actually directly address I/O ports in C, and directly addressing memory (via pointer arithmetic which oversteps the bounds of an object, or which puns the type of an object) invokes undefined behavior. Both those things depend on details of the underlying architecture, ABI, and operating system, and are abstracted away in C.

pjmlp 10y ago

> People often regard C code as inherently ugly because of nasty coding styles that were prevalent in the 80s and 90s Those code styles as still prevalent in 2016, speaking from the experience of occasionally having to look into how people write C code to integrate into Java, .NET, Python, Ruby at the enterprise level, which just stresses my point of view about the language. Specially since outside HN bubble many don't even know what a static analyser or code review are all about.

josefx 10y ago
Saw Hungarian notation used by two distinct developers in 2016. One of them freshly graduated and otherwise a halfway decent programmer. As far as I could tell both used it just as wrong as most developers did almost two decades ago. Bad styles find a way to live on.

marios 10y ago

What is wrong with declaring local variables at the top of functions ?

titzer 10y ago
Because you generally want to put declarations close to their uses to minimize their scope? Reduce cognitive load and improve local reasoning?
- wtbob 10y ago
  But in general functions shouldn't really be all that long anyway (if they are, break 'em up!). I kinda like declaring my variables all at the top — I think it looks nice & clean.
  - bluetomcat 10y ago
    Even in short functions, "declare it when it's needed" makes your program follow a data-flow style and enables you to use const more, since in many cases the initialization is the only assignment that you do to that variable.
- dllthomas 10y ago
  While the parent technically said "at the start of functions", at least C89 (I don't remember about K&R) allowed declarations at the start of any block. This is not incompatible with minimizing scope - just introduce more blocks. And in fact, introducing a block to bound the scope of a variable allows a smaller scope than simply declaring it halfway through a function, as you can also end it early.
majewsky 10y ago
If you declare a variable as `const`, you have to initialize it during declaration. So you have to place the declaration exactly where the value expression becomes available.
- bluetomcat 10y ago