Nim: nimpretty feature requests

[timotheecour]

• [x] nimpretty --margin=0 # means infinity (ie no line wrap); can pass any integer, eg 80, 120...
  EDIT this now exists: nimpretty --maxLineLen:N
• [ ] nimpretty --fixcase=true # when true, changes case of identifiers to same case as symbol declaration, eg: splitlines will become splitLines because symbol declared as splitLines
• [ ] nimpretty --safe # this one runs a subset of all transformations run by nimpretty that is known to work (eg, not break code)
• [ ] use a git hook to give a warning when PR would generate a style violation; so PR author can fix it before it gets in hands of reviewer, see [1]; this requires git nimpretty to only consider style violations local to PR diff. Note that it should be a warning, not an error (eg when a PR has to move a block of code and it may be undesirable to nimpretty it for whatever reason, or if running nimpretty would somehow result in broken code due to a bug in nimpretty)
• [x] nimpretty --tabwidth=2 # when set, changes tab width to requested value (useful when some source code uses tab width inconsistent with other code in a project)
  EDIT this now exists: nimpretty --indent:N

links

• [1] http://kaskavalci.com/using-git-hooks-to-format-your-code/
• https://stackoverflow.com/questions/43974371/run-git-clang-format-on-series-of-git-commits
• https://clang.llvm.org/docs/ClangFormatStyleOptions.html
• https://engineering.mongodb.com/post/succeeding-with-clangformat-part-1-pitfalls-and-planning/

[Araq]

Instead of --tabwidth you can fix the source file so that the first indentation uses the desired number of spaces. --margin is a bit against nimpretty's "zero configuration" philophy too. --fixcase will be though to support. ;-)

[FedericoCeratto]

fixcase should instead support user-configurable styles (snake_case, camelCase, ...) at file and whole-project granularity

[timotheecour]

(moved from top-post for easy individual reference wo creating a new issue)

• [ ] nimpretty --difflines:commit which is the exact analog of git clang-format which only applies formatting on lines that appear in the diff wrt commit This is very useful to apply formatting changes without creating un-necessary large diffs
  (especially when nimpretty changes its output over time; and it will)

[kuon]

Would it be possible to add support for stdin to stdout to nimpretty?

nimpretty - should read from stdin and write to stdout.

[pb-cdunn]

Also, nimpretty makes a mess of json %* macro code.

[narimiran]

Also, nimpretty makes a mess of json %* macro code.

Can you please post an example (as a separate issue, ideally), because I was not able to reproduce the mess you mention?

[pb-cdunn]

@narimiran , see #11937.

[polypus74]

Would it be possible to add support for stdin to stdout to nimpretty?

nimpretty - should read from stdin and write to stdout.

To compound this problem shell process substitution is broken because nimpretty renames input filepaths not ending in ".nim": nimpretty --out:/dev/stdout <(cat)

And complains cannot open /dev/fd/45.nim

Or /dev/stdin -> /dev/stdin.nim, for that matter.

[FedericoCeratto]

nimfmt now implements a feature to fix casing with user-configurable parameters

[Clyybber]

nimpretty's --maxLineLen option addresses the first point of this Issue (I updated the issue accordingly)