These entries returned by `readdir` are legacy of Unix API, we don't
really need them. Most APIs do not return them (for example Java
`Files.newDirectoryStream` or Python `os.listdir`).
* add `nextDirEntry` which returns `Maybe String`, so `Nothing` on
the end of directory unlike `dirEntry` which returns unspecified error
on the end of directory
* `dirEntry` is deprecated now, but not removed because compiler depends on it
* native implementation of `dirEntry` is patched to explicitly reset `errno`
before the `readdir` call: without it end of directory and error were
indistinguishable
* test added
* Add trailing newline on non-empty list in unlines
There are several reasons to do that:
* a line in a text file is something which ends with newline,
and the last line is not special
* `unlines []` should be different from `unlines [""]`
* `unlines (a ++ b) = unlines a ++ unlines b`
* Haskell does it
* Change lines function behaviour
To be able to use `C` functions for both Scheme and RefC: it was
not possible for `Buffer` before this PR.
As an example, `writeBufferData` and `readBufferData` functions are
removed: generic C backend implementations are used instead.
* add `strerror` function
* move `getErrno` to `System.Errno`
* use `strerror` in `Show FileError`
* on node there's no access to `strerror`, so `strerror` just converts the number to string
Convert `App.Control.Exception` interface to an alias to `HasErr`.
Probably `Exception` interface need to be deprecated or removed.
Note similar problem exists with `PrimIO` calling `PrimIO, Exception`,
also need to be fixed.
Fix this scenario:
```
throwBoth : Has [Exception String, Exception Int] es => App es ()
throwOne : Has [Exception Int] es => App es Int
throwOne {es} = handle {err = String} {e = es} throwBoth (\r => pure 1) (\e => pure 3)
```
With this commit it works, before this commit it failed with:
```
Error: While processing right hand side of throwOne. Can't find an implementation for Exception Int (String :: es).
TestException.idr:8:48--8:57
|
8 | throwOne {es} = handle {err = String} {e = es} throwBoth (\r => pure 1) (\e => pure 3)
| ^^^^^^^^^
```
Since `[a..b]` uses `takeUntil`/`takeBefore` indirectly those too had to
be changed to `public export` clashing with `Data.Stream` definitions.
A small readability refactor was made with the `compare` function from
`EqOrd`.
To be able to eventually refactor/extend `system` function: to be
able to specify a directory, environment variables, specify arguments
as array etc. Ideally it should be something like Rust
[`std::process::Command`](https://doc.rust-lang.org/std/process/struct.Command.html).
