line terminators when:
a) running under windows, and
b) the file on the disk (when DrRacket first opens it)
contains all CRLF line endings.
In all other situations, the file is saved with LF terminators.
Before this commit, DrRacket would always use the platform-specific
convention, regardless of the original content of the file.
closes PR 12242
This is a backwards incompatible change; there is a more complex change
that just stubs this stuff out that may be better that we may need
isntead of this commit.
being edited in DrRacket (via places)
Added an API to let tools have access to that
information (and compute more stuff)
Used that to make an online version of Check Syntax
which led to a separately callable Check Syntax API.
