This patch makes Splash correctly highlight strings in which a value
is interpolated next to a delimiter character. The fix is to enable
each `Grammar` implementation to decide whether two tokens should be
*merged*, which in turn enables `SwiftGrammar` to veto that string
interpolation delimiters should be merged with their predecesor.
This change adds SwiftLint to the project. For now, the rules are tweaked
to match the current state of the code base — but will over time be changed
back to their defaults in several cases.
Some smaller changes (mostly related to code style) were applied to the
project to remove all warnings.
This patch fixes syntax highlighting for the following scenario:
```
Type<GenericType>.call()
```
Highlighting generic types is especially tricky, since we want them to
be highlighted when appearing at the call site, like above - but we don’t
want to highlight them when they are being declared. Hopefully with this
fix all/most edge cases are covered.
