[MacPorts] #15712: Add versions to platforms

[MacPorts]

#15712: Add versions to platforms
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  Reporter:  raimue       |      Owner:  larryv
      Type:  enhancement  |     Status:  assigned
  Priority:  Normal       |  Milestone:  MacPorts 2.6.0
 Component:  base         |    Version:
Resolution:               |   Keywords:
      Port:               |
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Comment (by pmetzger):

 Link to the documentation below. I stole these examples from the web site.
 The syntax they use probably isn't feasible to steal for Tcl, but some of
 the ideas might be interesting to steal.

 Typically, you specify a package dependency constraint like:

 {{{
 "pkg1" {>= "3.2" & != "3.7"}
 }}}

 They can constrain multiple packages, eg:

 {{{
 ("pkg1" & "pkg2") | "pkg3" {>= "3.2" & != "3.7"}
 }}}

 You constrain where your package is available with separate constraints
 described in stanzas like this:

 {{{
 available: [ os != "darwin" | ocaml-version >= "4.00" ]
 }}}

 They can also do things like constraining individual arguments to build
 commands based on version constraints, like:

 {{{
 ["./configure" "--with-foo" {ocaml-version > "3.12"} "--
 prefix=%{prefix}%"]
 }}}

 which will only include --with-foo in the command for 3.12 and above.

 [https://opam.ocaml.org/doc/Manual.html Full Manual.]

-- 
Ticket URL: <https://trac.macports.org/ticket/15712#comment:26>
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