Allow a "file://" URL to specify a type that causes the path
to be installed as a link or static link. A type query like
that is mainly intended for use in a catalog, where a catalog
of local directories could create links as needed for other
packages (that might be pulled from other catalogs).
For some reason, I previously made the package manager parse file URLs
by stripping away "file://" and treating the rest directly as a
path. Maybe it was to support relative paths, or maybe it was to
implicitly disallow query and fragment parts of the URL, but it seems
like a terrible idea; I've switched to `string->url` plus `url->path`.
As a result, parsing now implicitly allows and ignores query and
fragment parts of a "file://" URL. That's intended as a feature,
allowing extra information to be attached to a path in, for example,
a catalog.
The source to the split packages is in repositories under the
`racket` organization on GitHub. The repositories are all named
according to the pkg name, except for multiple-package
repositories such as `racket/compiler` which is named based on the
old directory name without the `-pkgs` suffix. Thus
`pkgs/compiler-pkgs` -> https://github.com/racket/compiler
The Makefile has also been adjusted to pull packages from the
catalog when you type `make`. This currently relies on some tricks
that will break if you try to specify a particular set of `PKGS` on
the command line. We plan to improve this soon.
The packages in `pkgs/racket-pkgs` and `pkgs/base` are staying in
the repository, since they logically belong with the core code.
The `plt-services` package is still in the repository, but will
move out soon.
The combination of `--lookup`, `--clone`, and `--catalog` can provide
a one-step path from a snapshot's built implementation of a package to
a repository-linked clone, for example. In that situation, however,
`raco pkg` will have limited ability to detect that packages
originally drawn from the same repository are consistenly installed as
clones (and we can revisit if it turns out to be an issue).
The optimizer converts (car (cons X Y)) to (begin0 X Y) and then reduces
it to (begin Y X) if X is movable.
Check that the movement is safe for space and for continuation captures.
