Functions for manipulating and comparing Debian version strings. Compliant with Debian policy version 3.9.2. and Debian developers reference version 3.4.6
The following functions compare any two strings, that is these functions do not check whether the arguments are really legal debian versions. If the arguments are debian version strings, then the result is as required by debian policy. Note that two strings may be equivalent, that is denote the same debian version, even when they differ in syntax, as for instance "0:1.2.00" and "1.02-0".
compare x y returns 0 if x is eqivalent to y, -1 if x is smaller than y, and 1 if x is greater than y. This is consistent with Pervasives.compare.
Version strings may be the decomposed into epoch, upstream, and revision as described in debian policy section 5.6.12. An epoch is present if the version string contains a colon ':', in this case the leftmost colon separates the epoch from the rest. A revision is present if the string contains a dash '-', in this case the rightmost dash separates the rest from the revision.
A version string that contains no dash (hence, no revision) is called native. Otherwise it is called non-native, in this case the revision may be empty (example: "1.2-") or not.
A suffix of the upstream part of a native version, or the suffix of the revision part of a non-native version, may contain a part indicating a binary NMU (Debian Developers Reference, section 5.10.2.1). A binary NMU part is of the form "+bN" where N is an unsigned integer.
result type of the analysis of a version string. The binNMU part, if present, has been removed from the upstream (if native version) or revision (if non-native vesion).
val decompose : string -> version_analysisdecompose a version string
val compose : version_analysis -> stringrecompose a decomposed version string. For all v: equal(v,compose(decompose v)) = true. There may, however, be small syntactic differences between v and compose(decompose v)
val strip_epoch_binnmu : string -> version_analysisreturn a version without its epoch and without its binNMU part
val strip_epoch : string -> version_analysisreturn a version without its epoch part