[swift-evolution] Support for coding styles and "swift-format" tool

[Daniel Martín]

As Swift is getting traction in more and more platforms outside of 
Apple, we can expect that many coding styles different from what Apple 
imposes with SourceKit's indenting rules will emerge. According to 
https://bugs.swift.org/browse/SR-146, we now have decoupled indenting 
logic from SourceKit into its own library, and a "swift-format" tool is 
in the making.

I am working on adding support for different coding styles to libIDE. 
For example, with my changes you could decide how a case label should be 
indented with respect to its parent switch context, among other things. 
The current, hard coded indenting decisions in libIDE could be named the 
"Apple" style, just like Clang supports Google, LLVM, Mozilla, coding 
styles for C++. Also, this is something that can be supported by 
external tools like Xcode quite easily.

Do you think this is a good feature to have?

--
Daniel Martín