This patch implements relative-path semantics for the "source" facility resembling
those of cpp(1), documents the change, and improves the shlex test main to
make it easier to test this feature. Along the way, it fixes a name error
in the existing docs.
[Additional documentation markup changes for consistency by FLD.]
(1) Added and documented the capability for shlex to handle
lexical-level inclusion and a stack of input sources. Also, the input
stream member is now documented, and the constructor takes an optional
source-filename. The class provides facilities to generate error
messages that track file and line number.
(2) Add a convenience function to generate C-compiler style error
leaders.
Fred Drake
Guido van Rossum