For the scope of the language it never even comes up, because Noise is a simulator, it does not evaluate densities, it draws samples.
The point is that every value goes through the same operators. Add them, compare them, pass them to a function, put one in the condition of an if. You can even use a random variable to define another random variable:
bias ~ unif(0, 1) flips ~[10] bernoulli(bias) // bernoulli just took a distribution where a number normally goes.
and in if-stataments:
DistributionC = if DistributionA < DistributionB { 0 } else { 1 }
But you right, dirac only applies to continuous functions, in Noise is only refers to the dirac measure. I found this article a fun/nerd to make my point that everything "acts" as a distribution from the DX perspective, but under the hood 5 is just 5.
And a constant collapses back to a plain integer in the graph anyway, so 5 costs nothing.
[1] And feels philosophically like the unification in the underlying maths between discrete and continuous probability that you get when you apply measure theory