Re: rfc: (add-hook 'before-save-hook 'delete-trailing-whitespace)

[Thien-Thi Nguyen]

() address@hidden (Ludovic Courtès)
() Wed, 13 Jan 2010 11:53:01 +0100

   I agree, but adding such a hook would cause many gratuitous
   diffs, which then blur VCS history (using ‘git blame’ becomes
   almost useless).

Usually, once a project decides to use some whitespace policy,
there is a one-time change-only-whitespace commit after which
programmers are expected to adhere to the new policy (using
whatever tools they choose).  This way, the pain from gratuitous
diffs are minimized.

Another way to minimize pain is to instruct the diff program to
ignore whitespace (this means in practice `--ignore-space-change'
(-b) or `--ignore-space-at-eol' for "git diff").

Having said that, i see (count of affected lines by file below)
that even a one-time change will touch a lot of lines.  Hmmm.

   Instead, I’d suggest using ‘show-trailing-whitespace’.
   Unfortunately, that can’t be a per-file or per-directory local
   variable [0] so we can just kindly ask people to add it to
   their ‘.emacs’.  :-)

   What do you think?

I'd rather a clean break than relying on the chance that the
source will be opportunistically cleaned up going forward.

thi


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  | sort -nr
1395    gc-benchmarks/larceny/twobit-input-short.sch
1395    gc-benchmarks/larceny/nucleic2.sch
861     gc-benchmarks/larceny/twobit.sch
861     gc-benchmarks/larceny/twobit-input-long.sch
628     gc-benchmarks/larceny/twobit-smaller.sch
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278     doc/r5rs/r5rs.texi
201     module/language/ecmascript/parse-lalr.scm
129     module/sxml/upstream/SSAX.scm
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81      libguile/filesys.c
78      test-suite/tests/srfi-1.test
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57      test-suite/tests/sxml.xpath.test
57      module/sxml/upstream/SXPath-old.scm
51      libguile/ports.c
50      gc-benchmarks/larceny/sboyer.sch
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48      gc-benchmarks/larceny/nboyer.sch
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43      module/ice-9/format.scm
41      module/oop/goops.scm
41      libguile/posix.c
40      libguile/print.c
39      libguile/deprecated.c
39      doc/ref/api-modules.texi
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33      module/language/tree-il.scm
33      doc/ref/goops-tutorial.texi
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32      libguile/win32-socket.c
32      NEWS
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28      benchmark-suite/benchmarks/srfi-13.bm
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11      doc/ref/hierarchy.pdf
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4       guile-readline/ChangeLog-2008
4       emacs/gds-scheme.el
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4       doc/ref/scheme-debugging.texi
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4       doc/example-smob/image-type.c
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3       libguile/feature.c
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3       examples/box-dynamic-module/README
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1       libguile/chars.h
1       libguile/bitvectors.h
1       libguile/ChangeLog-2008
1       libguile.h
1       gc-benchmarks/larceny/run-benchmark.chez
1       gc-benchmarks/larceny/earley.sch
1       examples/scripts/simple-hello.scm
1       examples/modules/main
1       examples/modules/README
1       examples/compat/compat.h
1       examples/README
1       examples/Makefile.am
1       examples/ChangeLog-2008
1       emacs/gds-test.el
1       emacs/Makefile.am
1       doc/use-cases.fig
1       doc/tutorial/Makefile.am
1       doc/sources/unix-other.texi
1       doc/sources/jimb-org.texi
1       doc/ref/standard-library.am
1       doc/ref/mod-getopt-long.texi
1       doc/ref/misc-modules.texi
1       doc/ref/hierarchy.png
1       doc/ref/guile.texi
1       doc/ref/goops.texi
1       doc/ref/api-procedures.texi
1       doc/r5rs/Makefile.am
1       doc/example-smob/ChangeLog-2008
1       doc/ChangeLog-guile-doc
1       benchmark-suite/benchmarks/chars.bm
1       benchmark-suite/ChangeLog-2008
1       README.guile-vm
1       HACKING