EOF is not a character

Post by empath75 » Sat, Mar 14, 2020, 2:25 PM UTC

enriquto wrote: post #97

empath75 wrote: post #93

Earlier quoted context omitted.

I’m a community college drop out and have never taken a CS class and I use options in my code all the time. It’s just a wrapper around some value that is either Some(value) or None and you need to unwrap it and handle both possibilities for your code to compile. You don’t need to know anything about monads or ADT’s to understand it.

But do you understand that some values of a 32 bit int can be used to encode meta-data about a 8 bit char? If you understand both, which one is conceptually easier to you?

Post by teddyh » Sat, Mar 14, 2020, 2:35 PM UTC

nothrabannosir wrote: post #84

rectang wrote: post #19

Like NULL, confusion over EOF is a problem which can be eliminated via algebraic types. What if instead of a char, getchar() returned an Option ? Then you can pattern match, something like this Rust/C mashup: match getchar() { Some(c) => putchar(c), None => break, } Magical sentinels crammed into return values — like EOF returned by getchar() or -1 returned by ftell() or NULL returned by malloc() — are one of C's dra…

What always annoyed me about C is that it has all the tools to simulate something approaching this, save for some purely syntactical last-mile shortcomings. We can already return structs; if only there were a way to neatly define a function returning an anonymous struct, and immediately destructure on the receiving end. Something like: #include struct { int err; char c; } myfunc() { return { 0, 'a' }; } int main(int…

Post by agumonkey » Sat, Mar 14, 2020, 2:54 PM UTC

Post by juped » Sat, Mar 14, 2020, 3:09 PM UTC

teddyh wrote: post #103

nothrabannosir wrote: post #84

Earlier quoted context omitted.

What always annoyed me about C is that it has all the tools to simulate something approaching this, save for some purely syntactical last-mile shortcomings. We can already return structs; if only there were a way to neatly define a function returning an anonymous struct, and immediately destructure on the receiving end. Something like: #include struct { int err; char c; } myfunc() { return { 0, 'a' }; } int main(int…

> We can already return structs AFAIK, no? You can return a pointer to a struct, and you can pass whole structs as arguments , but not, IIRC, return them from functions. EDIT: Apparently you can , sort of, but not portably; how exactly it is defined to work depends on the compiler, and each compiler might define it differently. This means that if you’re using a library which returns a struct and your program use a di…

Post by nixpulvis » Sat, Mar 14, 2020, 3:11 PM UTC

astrobe_ wrote: post #66

nixpulvis wrote: post #30

Earlier quoted context omitted.

I'm sorry you don't find it great (I still do). Integers are not characters. Integers are numbers like -1337, 0, and 42. Characters are things that compose strings of text. These are not the same kind of thing at all. Just because APIs may be leaky, and some of these APIs are held in very high regard doesn't change that fact.

In the end, integers, floating point numbers, "text\n", emojis etc. are just sequences of bytes. You choose to acknowledge it and take advantage of it, or you don't.