This function will parse a string as a semantic version. The parsing is "relaxed",
allowing for a leading "v" and the least significant parts can be left out
when they are zero (e.g. "v1.0.0" is just as valid as "1").
Parsed semvers are a custom type (not a string, not a vector). They can be directly compared to each other and to strings (i.e. they can be coalesced to a string, depending on the coalescer).
(semver "v1.2")➜ semver object(semver "foo")➜ error(eq? (to-string (semver "v1.0")) "1.0.0")➜true(eq? (semver "v1.0") "1.0.0")➜true(with human coalescing)(gt? (semver "v1.0") (semver "v1.0.1"))➜false