Maven Version Order Spec: Implicit Initial Separator and Trimming

Hi,

I'm ironing out my understanding of the Maven Version Order Spec
<https://maven.apache.org/pom.html#Version_Order_Specification> and had
three questions: one was related to an implicit separator before the
beginning of versions, and the next two were related to trimming.

------------
*Implicit Separator*

From my (limited) understanding, the maven-artifact-3.9.11 tool seems to
use hyphens to create a ListItem, and an initial hyphen would suggest the
creation of the tokens list.  So if the version begins with a '-', there's
a nested list because the tokens are an empty non-numeric segment (the
implicit initial hyphen) followed by the hyphen-separator numeric token
"-1".  The maven-artifact jar confirms this for versions "1" and "-1",
which results in 1 > -1:

tokens(1) = [1]
tokens(-1) = [[1]]

1 > -1

----

I did run into one seeming inconsistency for this idea when the tool
compares "sp" and "ga-1"

tokens(sp) = -sp = [sp]
tokens(ga-1) = -1 = [[1]]     // trimming removes "ga"


*sp < ga-1      // maven-artifact output is unexpected because sp > ""   *


----

The argument may be made that the *initial implicit separator is a period*,
and that all versions are enclosed by a list.  This would explain the
nested list of "-1":

tokens(sp) = .sp = [sp]     // all versions are a ListItem

tokens(ga-1) = .ga-1
        = -1         // trimming starting from the last hyphen

        = [[1]]      // ListItem "-1" is enclosed within the initial list

sp < [-1]   // special qualifier "sp" is less than hyphen-numeric token [1]

----

The implicit period separator still holds for "-1" due to normalization and
trimming:

tokens(-1) = .-1

    = 0.0-1   // normalization adds zeroes
    = -1        // trimming removes zeroes
    = [[1]]     // initial list holds a hyphen-numeric token


------------

*Trimming*
The remaining confusion I had was related to trimming: consider "--1--" and
"--1-"

My understanding of the spec would be the following (excluding the initial
separator idea above):

tokens(--1--)

    = -0-1-0-0    // normalization: "Empty tokens are replaced with "0" "
    = -1              // trimming: "the trailing "null" values...are
trimmed. This process is repeated at each remaining hyphen "
    = [[1]]            // initial list (or implicit hyphen) enclosing
hyphen-numeric token

tokens(--1-)
    = -0-1-0
    = -1
    = [[1]]

However, the maven-artifact output is different:



*1. -1-- -> 1; tokens: [[1]]   -1-- > --1-2. --1- -> 1; tokens: [[[1]]]*

It seems like trimming is not happening after the "-1" token.

----
ABC vs. -ABC Problem

I'm having trouble reconciling the following case of "abc" vs. "-abc".  Via
the trimming logic, I'd expect

tokens(-abc) = "0-abc" (empty tokens replace with "0")
    = "abc" (trimming)
    = tokens(abc)

but the output of the tool is below:



*1. abc -> abc; tokens: [abc]   abc < -abc2. -abc -> abc; tokens: [[abc]]*

------------


So to recap, had three questions:

1) should versions be treated as if there's an implicit separator?
2) how should trimming/tokenization work for "--1--" and "--1-"?
3) how should trimming/tokenization work for "abc" and "-abc"?

Hope this isn't too confusing and/or lengthy.  Thanks for your time and
have a good day!


Best,

Ron