is-thirteen in Go

As COVID-19 lockdown is still going on, Labor Day is another indoor day just like how it has been for the last month. I'm surprised I even remember what day it is. To make myself feel less useless and bored, I decided to write a useless (?) Go module port called is-thirteen from its original JS version . With its extensive API, you can:

Check whether a number is 13

...
    is.Number(13).Thirteen()               // true
    is.Number(12.8).Roughly.Thirteen()     // true
    is.Number(6).Within(10).Of.Thirteen()  // true
    is.Number(2007).YearOfBirth.Thirteen() // true

    // check your math skillz
    is.Number(4).Plus(5).Thirteen()     // false
    is.Number(12).Plus(1).Thirteen()    // true
    is.Number(4).Minus(12).Thirteen()   // false
    is.Number(14).Minus(1).Thirteen()   // true
    is.Number(1).Times(8).Thirteen()    // false
    is.Number(26).Divides(2).Thirteen() // true
...

or

Check whether a string is 13

...
    // check your spelling and chemistry skillz
    is.String("tHirTeEn").Thirteen()              // true
    is.String("nethtire").AnagramOf.Thirteen()    // true
    is.String("neetriht").Backwards.Thirteen()    // true
    is.String("aLumInUm").AtomicNumber.Thirteen() // true
...

is-thirteen is stable with 98% test coverage. Check it out over on Github!