Modifies parsing to return strongly-typed `Thunk`s, which contain both
the function implementation, as well as the correct number of arguments.
This moves unknown function and function argument count mismatch errors
to parse time.
- Instead of changing the current directory with `env::set_current_dir`
to be implicitly inherited by subprocesses, we now use
`Command::current_dir` to set it explicitly. This feels much better,
since we aren't dependent on the implicit state of the process's
current directory.
- Subcommand execution is much improved.
- Added a ton of tests for config parsing, config execution, working
dir, and search dir.
- Error messages are improved. Many more will be colored.
- The Config is now onwed, instead of borrowing from the arguments and
the `clap::ArgMatches` object. This is a huge ergonomic improvement,
especially in tests, and I don't think anyone will notice.
- `--edit` now uses `$VISUAL`, `$EDITOR`, or `vim`, in that order,
matching git, which I think is what most people will expect.
- Added a cute `tmptree!{}` macro, for creating temporary directories
populated with directories and files for tests.
- Admitted that grammer is LL(k) and I don't know what `k` is.
Just's first parser performed both parsing, i.e the transformation of a
token stream according to the language grammar, and a number of consistency
checks and analysis passes.
This made parsing and analysis quite complex, so this diff introduces a
new, much cleaner `Parser`, and moves existing analysis into a dedicated
`Analyzer`.
Eventually, there will probably be a `crate` visibility specifier that
does the same thing as `pub(crate)`. This commit replaces `pub` with
`pub(crate)`, so when `crate` is available we can easily switch to it.
`env_var(key)` looks up the value of the environment variable with name `key`, aborting execution if it is not found.
`env_var_or_default(key, default)` looks up the value of the environment variable with name `key`, returning `default` if it is not found.
