Re: [gentoo-dev] RFC: Future EAPI version operator changes

[Jan Chren (rindeal)]

First of all thank you for the research and wish you a good luck in
making the changes happen.


## Reordering to PACKAGE OP VERSION

<cat/pkg> [<operator> <version>] [:<slot>]

is more sane than

<cat/pkg> [:<slot>] [<operator> <version>]

even though it's not so "hierarchically correct".

Thus instead of writing

dev-foo/bar:4===4.1

one would write

dev-foo/bar==4.1*:4=

which is nicely readable.

But in case the box brackets notation gets incorporated (as in Exheres),

<cat/pkg> [:<slot>] [[<operator> <version>]]

is the way to go.


## Version ranges

dev-foo/bar:0[(>=2 && <4) || (>=6 && <10)][baz?]

looks the most promising to me as it allows to include and exclude any
number of ranges.


## Things not included

### Comments/annotations

Currently, there is no way to put inline comments to *DEPEND, IUSE,
..., thus the only supported way is to put the comments above the
specification and somehow tell the reader what part of the
specification is the comment about. For 3-4 deps it's acceptable, for
20+ it's insane and thus no one does it, losing valuable information
about the reasoning by doing so.

Mu current workaround is:

DEPEND_A=(
   # comment
   "cat/pkg..."
   "|| ("
      # comment
      "cat/foo"
      "cat/bar"
   ")"
)
DEPEND="${DEPEND_A[*]}"


### Logical operators for groups

#### OR

Currently there is no way to specify:

foo||bar? (
  cat/pkg
)

and one has to copy&paste a lot:

foo? (
  cat/pkg
)
bar? (
  cat/pkg
)

#### AND

AND can be specified via nested groups:

foo? (
  bar? (
    cat/pkg
  )
)

but this syntax is verbose and not explicit.

foo&&bar? (
  cat/pkg
)

would be much more readable.