New: Pseudosem

LOOT’s version string comparison algorithm has been split into its own library, Pseudosem! It’s a header-only C++11 library that comes with a suite of tests, and implements version comparison as described by Semantic Versioning, but with some extensions to the allowed syntax to accommodate most forms of version strings (hence “permissive”).

The syntax extensions are:

• Leading zeroes (eg. 0.05.1)
• Arbitrary number of release version parts (eg. 1.2.3.4.5)
• Space, colon, hyphen and underscore prerelease separators (eg. 1.0.0 alpha:1-2_3)
• Case insensitivity

Usage is simple, there’s a single C-like compare function:

#include <pseudosem.h>
#include <iostream>

int main() {
    std::string v1("1.0.0");
    std::string v2("2.4.0");

    int result = pseudosem::compare(v1, v2);

    if (result < 0)
        std::cout << "v1 is an earlier version than v2";
    else if (result == 0)
        std::cout << "v1 is an equivalent version to v2";
    else
        std::cout << "v1 is a later version than v2";

    return 0;
}

The above will print v1 is an earlier version than v2, obviously.

I split it from LOOT’s code because BOSS’s new developer is interested in using the same code for BOSS, since its existing version comparison is a little broken. Hopefully it’ll turn out to be a generally useful thing beyond that.