This tells Idris where to look for packages in addition to the default
places (under $PREFIX and ./depends/). This should allow package
managers a bit more flexibility.
When bootstrapping, we're building things without packages being
available, so we can't expect to find them when looking for
dependencies. So, we find them another way, with an environment
variable. This flag is to tell Idris not to worry about missing
dependencies in this situation.
We also need to update the bootstrapping code, to deal with the new
version number format and new flag in the ipkg files for the libraries.
I think it's still safe to build from the previous version though - lets
see if CI agrees!
Now reporting an error if we can't find a package that satisfies the
constraints. The version number field can still be a string (as it used
to be) but will give a deprecation warning - and the old style version
string wasn't used anyway.
Version constraints can have an upper and/or lower bound, which can be
inclusive or not.
Packages are now installed in a directory with their version number.
On adding a package directory, we now look in a local 'depends'
directory first (to allow packages to be installed locally to another
project) before the global install directory.
Dependencies can have version bounds (details yet to be implemented) and
we pick the package with the highest version number that matches.
This is an alternative to using `fastUnpack` and `fastPack` to work
on lists of characters.
Using this to refactor the lexer and benchmarking the resulting
compiler on building idris2 shows it's 3 to 5s slower than the
current implementation that goes via `List Char`.
This may be backend-dependent so I still push this to contrib,
with the plan of running further benchmarks in the future.
