Add conditional expressions of the form:
foo := if lhs == rhs { then } else { otherwise }
`lhs`, `rhs`, `then`, and `otherwise` are all arbitrary expressions, and
can recursively include other conditionals. Conditionals short-circuit,
so the branch not taken isn't evaluated.
It is also possible to test for inequality with `==`.
- 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.
This is done for two reasons:
1. Such names cannot be given on the command line, since clap will
intercept them and wrongly interpret them as flags.
2. The name '---' can conflict with yaml document delimiters. Kind of
speculative, but I was thinking that it would be nice to make sure that
'---' and '...' are illegal in a justfile, so that that one can be
included in a yaml document stream. Is this silly? I am really not sure.
This is backwards incompatible, but I don't think anyone will notice,
since names that start with '-' are likely to be rare.
Recipes may now have a final variadic parameter:
```make
foo bar+:
@echo {{bar}}
```
Variadic parameters accept one or more arguments, and expand to a string containing those arguments separated by spaces:
```sh
$ just foo a b c d e
a b c d e
```
I elected to accept one or more arguments instead of zero or more arguments since unexpectedly empty arguments can sometimes be dangerous.
```make
clean dir:
rm -rf {{dir}}/bin
```
If `dir` is empty in the above recipe, you'll delete `/bin`, which is probably not what was intended.
The grammar now permits blank lines in recipes.
Note that inside of recipes, the token `NEWLINE` is used instead of the
non-terminal `eol`. This is because an `eol` optionally includes a
comment, whereas inside recipes bodies comments get no special
treatment.
If a `#...` comment appears on the line immediately before a recipe, it
is considered to be a doc comment for that recipe.
Doc comments will be printed when recipes are `--list`ed or `--dump`ed.
Also adds some color to the `--list`ing.
Fixes#84
Looks like this:
```make
recipe argument default-argument='default value':
echo argument is {{argument}}
echo default-argument is {{default-argument}}
```
Thanks @deckarep for the feature request!
Fixes#49
