PackageVersion.regex.txt

# Matches a Package Name with a Version.  
# Includes captures for Name, Version, Major, Minor, Patch, Build, and Prerelease, and Extension
^                            # Match the start
(?<Name>                     # The (?<Name>) is...
    .+?(?=\z|[\.\-\@]\d+)    # ...anything until a . followed by a digit (or end of string)
)
[\.\@]                       # Now we match a dot, at, or dash
(?<Version>                  # The (?<Version>) is...     
    (?<Major>\d+)[\.\-]      # A (?<Major>) version digit, followed by a dot
    (?<Minor>\d+(?:[\.\-])?)?    # [Optional] a (?<Minor>) version digit, followed by a dot
    (?<Patch>\d+(?:[\.\-])?)?    # [Optional], a (?<Patch>) version digit, followed by a dot
    (?<Build>\d+(?:[\.\-])?)?    # [Optional], a (?<Build>) version digit, followed by a dot
    (?(Build)                # [Optional], If a (?<Build>) was found
        (?:(?=))             # capture nothing and move on
        |                    # Else
        \+(?<Build>[\w-]+)   # Match a + followed by a build identifier
    )?
    (?:                      # [Optional]
    -                        # match a - 
    (?<Prerelease>[\w-]+)       # followed by a (?<Prerelease>) identifier
    )?                       
    (?(Build)                # [Optional], If a (?<Build>) was found
        (?:(?=))             # capture nothing and move on
        |                    # otherwise
        \+(?<Build>[\w-]+)   # Match a + followed by a build identifier
    )?
)
(?:                          # [Optional]
    \.                       # Match a final .
    (?<Extension>            # The (?<Extension>) is
        .+?$                 # anything until the end of the string
    )
)?