Google Summer of Code 2022 Coding exercise

Goal: Implement a very word frequency counter

Your task is to provide the missing implementation for functions and structures in wordstat.c. The basic usage might look like this:

WordStat *ws = WordStatNew(" ", false);

if (!ws) {
    /* error */
}

WordStatAddText(ws, "My simple sentence for my GSoC");

char *word = WordStatGetMostFrequent(ws, &num_occur);

assert(word);
assert(strcmp(word, "my") == 0);

assert(WordStatGetTotal(ws) == 6);

free(word);
WordStatFree(ws);

What's provided:

In this repository is a basic structure without the implementation and source code for a binary with few tests included. Build system used in this project is meson. Files that are included in this repository are:

• meson.build -- configuration for the build
• meson_options.txt -- meson build option definitions
• README.md -- this file
• main.c -- binary using the WordStat implementation with various tests
• wordstat.h -- public header file for callers
• wordstat.c -- file prepared for your implementation

The only file you should need to touch is wordstat.c. The rest is provided to ease testing of your implementation.

Compilation and testing:

In order to compile this project you first need to configure meson in a separate directory, most commonly this is called build:

meson build

Now you can compile the project using ninja either directly from the directory or with -C path/to/directory:

ninja -C build

Once the build is complete you will have a binary called wordstat in the build directory which you can run to test your implementation:

build/wordstat

Or you can combine these steps by running:

ninja -C build test

although due to the size of the code and simplicity all tests show up as only one test, but you will get the output in case the test suite fails.

Test design

There are few tests in the main.c file which will run when you execute the binary. This is provided to you so that you can write your implementation using test driven development if that's what you like. By default the binary will stop after first failed test allowing you to progress at your own pace. If, however, that is not what you prefer in this situation and you would rather the tests to continue after non-critical failures, you can reconfigure your project build with the option run_all_tests like so:

meson -Drun_all_tests=true --reconfigure build

Implementation

The design of WordStat structure is completely up to you and is invisible to callers (in our case the main binary with the tests). You can introduce new internal functions, macros or whatever you like, but all of it should be contained inside wordstat.c. You are allowed to use additional includes, but should not add any build dependency. The only non-standard library you are allowed to use is glib but using it is not required in the slightest.

The implementation and algorithms are completely up to you. If you allocate any memory, do not forget to free it once no longer needed.

APIs

APIs are slightly documented in comments above them, but we might've of course forgot something. If you are unsure, then:

• try to read the comments again
• check the variable types thoroughly
• see how it is being used in the tests
• feel free to ask if you feel like anything is missing

There are no minus points for asking questions, communication is encouraged.

Caveats

For simplicity's sake it is not defined which word is the most frequent and should be returned in case there are two words that have the same number of occurrences. Hence the tests do not even test for this option.

Feel free to ask any questions.