Preparation for #865, which proposes adding a flag which outputs which
config options are used during formatting.
This PR should not make any difference to functionality. A lot of this
was search-and-replace.
Some areas worthy of review/discussion:
- The method for each config item returns a clone of the underlying
value. We can't simply return an immutable reference, as lots of
places in the code expect to be able to pass the returned value as
`bool` (not `&bool). It would be nice if the `bool` items could
return a copy, but the more complex types a borrowed reference... but
unfortunately, I couldn't get the macro to do this.
- A few places (mostly tests and `src/bin/rustfmt.rs`) were overriding
config items by modifying the fields of the `Config` struct directly.
They now use the existing `override_value()` method, which has been
modified to return a `Result` for use by `src/bin/rustfmt.rs`. This
benefits of this are that the complex `file_lines` and `write_mode`
strings are now parsed in one place (`Config.override_value`) instead
of multiple. The disadvantages are that it moves the compile-time
checks for config names to become run-time checks.
One notable feature is this this adds support for the experimental
`let x = loop { ... break $expr; }` syntax. This also includes a
test for formatting all the break and continue variations.
* Change required to prevent a trailing space at the end of a separate module being propagated
* Detect the start of the output file rather than the start of the input file when deciding whether to output preceding snippets - this stops unnecessary whitespace and blank lines from being inserted when spans and statements are output in an order other than that from the input file.
* Add code to prevent space from being added with the prefix snippet if a) the snippet is entirely horizontal whitespace, or b) the snippet contains whitespace followed by a newline. This prevents trailing spaces at the end of a line from being added.
* Tests for this issue
* Tidy up `match` statements
* Add test with blank lines between `use` statements
* Add config options for combinations of lines and items
* Reordering of import lines implemented.
* Changed nested matches to tuple pattern matching
* Added ordering of path list items to the ordering of use declarations
* Move `format_imports` and `format_import` methods to `imports.rs`
* Add comment to explain how `use` declarations are split off while walking through a module
* Change `ImportReordering` config option to separate boolean options
This commit adds a very rough implementation of handling the specified
line ranges in `config.file_lines_map` for statements. It reformats a
statement if its span is fully contained in the set of lines specified
for the file.
The implementation here is intended as a proof of concept, and
demonstration that the machinery added in the preceding commits is
functional. A final implementation would likely hook in via the
`Rewrite` trait.
Refs #434
