Introduction Currently we have a generic list container which uses void pointers to allow anything to be stored. Previously, we created a type safe string hashtable wrapping the generic hashtable. We want to do the same thing for our list and so now we’re going to create a type safe string list wrapping our generic list. Design Unlike the string hashtable we want to extend the our string list to have some string specific functionality....
Introduction Lists (dynamic arrays) are yet another super useful data structure that C just doesn’t have. C arrays are great for when you can get away with a fixed size but not so fun if you need to dynamically expand because you don’t know quite how many elements you’ll need. You could use a series of reallocs and memmoves but that’s going to get old really fast. It’s also error prone and not obvious when growth is needed....
Introduction We have this amazing generic hashtable and we can put pretty much anything we want into it, but it has a few flaws. It uses void pointers and has a pretty verbose setup with that callback struct. If you’re using the same types over and over again you’ll have a lot of redundant code. There is also a much more pressing issue of void pointers. They remove type safely. It would be really bad if you passed the wrong type to a hashtable meant for another....
Introduction So, C doesn’t have a native hashtable object but that’s not a problem because we can use one one someone else wrote. Lack of a robust standard library is probably the biggest impoundments of working with C. It’s a real shame C doesn’t natively support hashtables because they are so versatile. You should keep this saying in mind, “when in doubt hash it out”. It works for programming and for life in general....
One task that always annoys me when I work with C is building strings. snprintf is all well and good if I know exactly the format I want. It falls down with anything that needs to be build iteratively and dynamically. Other languages that have built in strings will automatically create a new string when concatenating but C doesn’t actually have “strings”. I realize that concatenating strings is really inefficient and should be avoided for all but the smallest and simplest string....