hello nimph

.github/workflows/ci.yml

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+name: CI
+on: [push, pull_request]
+
+concurrency: # Cancel stale PR builds (but not push builds)
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.sha }}
+  cancel-in-progress: true
+
+jobs:
+  build:
+    strategy:
+      fail-fast: false
+      matrix:
+        target:
+          - os: linux
+            cpu: amd64
+            TEST_LANG: c
+        include:
+          - target:
+              os: linux
+            builder: ubuntu-20.04
+            shell: bash
+    defaults:
+      run:
+        shell: ${{ matrix.shell }}
+
+    name: '${{ matrix.target.os }}-${{ matrix.target.cpu }}-${{ matrix.target.TEST_LANG }}'
+    runs-on: ${{ matrix.builder }}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - name: Fetch nimble
+        run: |
+          wget https://github.com/nim-lang/nimble/releases/download/latest/nimble-linux_x64.tar.gz
+          tar xvf nimble-linux_x64.tar.gz
+          echo "$PWD" >> $GITHUB_PATH
+
+      - name: Build nimph
+        run: |
+            nimble setup -l
+            nimble build
+
+      - name: Check formatting
+        run: |
+          find -name "*.nim"  ! -path "./tests/before/*" ! -path "./nimbledeps/*" -print0 | xargs -0 -n1 ./nimph
+          git diff --exit-code
+          find -name "*.nim"  ! -path "./tests/before/*" ! -path "./nimbledeps/*" -print0 | xargs -0 -n1 ./nimph --check

.gitignore

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+nimbledeps
+/nimph

README.md

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+# Nimph
+
+Nimph is an opinionated source code formatter for the Nim language, aiming to
+take the drudgery of manual formatting out of your coding day.
+
+Following the great tradition of [`black`](https://github.com/psf/black/),
+[`prettier`](https://prettier.io/), [`clang-format`](https://clang.llvm.org/docs/ClangFormat.html)
+and other AST-based formatters, it discards existing styling to create a
+consistent and beautiful codebase.
+
+## Usage
+
+Install `nimph`, then run it on some files:
+
+```sh
+# Format the given files in-place
+nimph file0.nim file1.nim
+
+# Format the given files, writing the formatted code to /tmp
+nimph file0.nim file1.nim --outdir:/tmp
+
+# Use --check to verify that a file is formatted correctly - useful in CI
+nimph --check somefile.nim || echo "Not formatted!"
+
+# You can format stuff as part of a pipe using `-` as input:
+echo "echo 1" | nimph -
+```
+
+For bonus points, replace `nimpretty` with a symlink to `nimph` - similar
+command line options are supported ;)
+
+## Installation
+
+`nimph` can be compiled or installed using `nimble` version `v0.14.2`+:
+
+```sh
+nimble -l setup
+nimble build
+```
+
+## Priorities
+
+`nimph` aims to format code in such way that:
+
+* it remains semantically unchanged, aka correct (!)
+  * the AST is checked for equivalence before writing the formatted code to
+    disk - on mismatch, the code is left untouched
+* it remains simple, consistent and pleasant to read
+  * _most_ code should look as good as or better than its hand-formatted
+    counterpart
+* diffs are kept at a minimum
+  * diff-inducing constructs such as vertical alignment are avoided, for more
+    productive merges
+* it broadly follows the [Status Nim style guide](https://status-im.github.io/nim-style-guide/)
+  and [NEP1](https://nim-lang.org/docs/nep1.html)
+  * this is tool aimed at making collaboration easier, with others and your
+    future self
+  * where NEP1 contradicts itself, see above
+
+The formatting rules are loosely derived from other formatters that already have
+gone through the journey of debating what "pleasing to read" might mean while
+making adaptations for both features and quirks of the Nim parser.
+
+If in doubt, formatting that works well for descriptive identifiers and avoids
+putting too much information in a single like will be preferred.
+
+## FAQ
+
+### Why use a formatter?
+
+A formatter removes the tedium of manually adding structure to code to make it
+more readable - overlong lines, inconsistent indentation, lack of visual
+structure and other small distractions quickly nibble away at the mental budget
+available for writing code while a formatter solves this many many other things
+at the press of a button.
+
+When you work with others, debates and nitpicking over style go away and
+collaborative efforts can focus on substance instead.
+
+Finally, the code is likely to look better - manually formatting code takes a
+lot of effort which ultimately can be spent better elsewhere - as such, poorly
+formatted code ends up being more common than not.
+
+### But I've spent a significant part of my life realigning code and now it's lost!
+
+https://en.wikipedia.org/wiki/Sunk_cost
+
+### How do I introduce `nimph` in an existing codebase?
+
+Assuming `git` is used, format all code using `nimph`, put it in a single commit
+and add a CI rule to ensure that future commits are all formatted using the same
+`nimph` version.
+
+Formatting commits can be ignored for the purpose of `git blame` by adding a
+file named `.git-blame-ignore-revs` containing the formatted source code to the
+root of the project:
+
+```sh
+cd myproject
+
+# Format all source code with nimph
+find -name "*.nim" -exec nimph {} \;
+
+# Create a single commit with all changes
+git add -A && git commit -m "Formatted code with nimph"
+
+# Record the commit hash in the blame file
+echo "# Formatted code with nimph" >> .git-blame-ignore-revs
+echo $(git rev-parse HEAD) >> .git-blame-ignore-revs
+```
+
+then configure git to use it:
+```sh
+git --global config blame.ignoreRevsFile .git-blame-ignore-revs
+```
+
+The same strategy can be used when upgrading `nimph` to a new version that
+introduces formatting changes.
+
+### `nimph` complains about my code!
+
+One of several things could have happened:
+
+* The code was not valid enough - `nimph` can only parse valid Nim grammar and
+  while it would be nice to handle partially formatted stuff gracefully, we're
+  not there yet.
+* The parser has a bug and is unable to parse valid Nim code
+  * Probably you can move some comments around to make it work!
+* the formatter has a bug and the resulting formatting is invalid
+  * Probably you can move some comments around to make it work!
+* the AST equivalence checker complains
+  * This often happens in complex expressions such as `do`  and parenthesis used
+    for indent purposes where the Nim grammar has ambiguities and parsing
+    complexity - it can usually be worked around by simplifying complex
+    expressions, introducing a template or similar
+  * It could also be that the AST checker is too strict - the Nim parser will
+    generate different AST:s depending on whitespace even if semantically there
+    is no difference
+
+Regardless of what happened, `nimph` takes the conservative approach and retains
+the original formatting!
+
+If you have time, try to find the offending code snippet and submit an issue.
+
+### Why the cited formatters in particular?
+
+* `black` because of our syntactic similarity with Python and its
+  [stability policy](https://black.readthedocs.io/en/stable/the_black_code_style/index.html#stability-policy)
+* `prettier` for its wisdom in how formatting [options](https://prettier.io/docs/en/option-philosophy)
+  are approached and for the closeness to user experience of its developers
+* `clang-format` for being the formatter that made me stop worrying about
+  formatting
+  * its secret sauce was treating formatting as a balancing of priorities rather
+    than a mechanical stringification using a [lowest-penalty](https://youtu.be/s7JmdCfI__c?t=640)
+    algorithm
+
+### What is meant by consistency?
+
+* Similar constructs are formatted with similar rules
+  * Does it look like a list? Format it with list-like rules regardless if
+    its a parameter list, array of values or import list
+* Original styling is generally not preserved - instead, the formatting is based
+  on the semantic structure of the program
+* Spacing emphasizes structure and control flow to help you read the code
+
+`nimph` makes your code consistent without introducing hobgoblins in your mind!
+
+### Why are there no options?
+
+The aim of `nimph` is to create a single consistent style that allows you to
+focus on programming while `nimph` takes care of the formatting, even across
+different codebases and authors.
+
+Consistency helps reading speed by removing unique and elaborate formatting
+distractions, allowing you, the experienced programmer, to derive structural
+information about the codebase at a glance.
+
+The style might feel unfamiliar in the beginning - this is fine and not a reason
+to panic - a few weeks from now, you'll forget you ever used another one.
+
+### Do you accept style suggestions and changes?
+
+Yes! The project is still in its early phase meaning that the style is not yet
+set in stone.
+
+To submit a proposal, include some existing code, how you'd like it to be
+formatted and an option-free algorithm detailing how to achieve it and how the
+outcome relates to the above styling priorities.
+
+When in doubt, look at what other opinionated formatters have done and link to
+it!
+
+Eventually, the plan is to adopt a [stability policy](https://black.readthedocs.io/en/stable/the_black_code_style/index.html#stability-policy)
+similar to `black`, meaning that style changes will still be accepted, but
+introduced only rarely so that you don't have to worry about massive PR-breaking
+formatting diffs all the time.
+
+### Why does the formatting code look an awful lot like the Nim compiler renderer?
+
+Because it is based on it, of course! As a starting point this is fine but the
+code would benefit greatly from being rewritten with a dedicated formatting
+AST.
+
+In particular, the comment handling is done in a hand-wavy manner with bits and
+pieces of the old code mixed with new heuristics resulting in quite the mess.
+
+### Should it be upstreamed?
+
+Maybe parts - feel free to make PR:s to the Nim repo from this codebase! That
+said, the aim of a compiler is to compile while a formatter formats - we are not
+the same.
+
+### What about `nimpretty`?
+
+`nimpretty` formats tokens, not the AST. Use whichever you like better, but keep
+a backup if you don't use `nimph` :)
+
+### Why 88 characters?
+
+This is an experiment.
+
+Astute and experienced programmers have noticed two things: longer variable
+names aren't that bad and monitors have gotten bigger since the 80 standard was
+set.
+
+Going beyond allows code that uses descriptive names to look better - how much
+extra is needed here is an open question but 10% seems like a good start for a
+language like Nim which defaults to 2-space significant indent and a naive
+module system that encourages globally unique identifiers with longer names.
+
+### What about comments?
+
+`nimph` currently touches comments as little as possible - specifically, they
+are not re-flowed or re-aligned and the aim is to make them sticky to where they
+were originally written.
+
+Improvements in this area are much welcome - the compiler AST was not really
+written with comment preservation in mind and `nimph`'s handling is not great.
+
+### What features will likely not be added?
+
+* formatting options - things that change the way the formatting is done for
+  aesthetic reasons - exceptions here might include options that increase
+  compatiblity (for example with older Nim versions)
+* semantic refactoring - reordings of imports etc - the focus is on style only
+
+### What's with the semicolons?
+
+Nim's grammar unfortunately allows the use of either `,` or `;` in some places
+with a subtly different AST being produced which _sometimes_ has a semantic
+impact - `nimph` takes a conservative approach here and uses `;` to avoid
+ambiguity.
+
+Future versions may try to identify where `,` can be used safely - very few
+programmers _really_ want `;` judging from the frequency with which it is used.
+
+Regardless, you can usually type either and `nimph` will clean it up.

config.nims

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+# begin Nimble config (version 2)
+when withDir(thisDir(), system.fileExists("nimble.paths")):
+  include "nimble.paths"
+# end Nimble config
+
+switch("p", "$projectDir/nimbledeps/pkgs2/nim-2.0.0-35b9d926d314ce8c3326902c138f5c2247cfd390/compiler")
+switch("p", "$projectDir/../nimbledeps/pkgs2/nim-2.0.0-35b9d926d314ce8c3326902c138f5c2247cfd390/compiler")

copying.txt

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+=====================================================
+nimph code formatter
+
+Copyright (C) 2023 Jacek Sieka. All rights reserved.
+
+
+Based in large parts on code from the Nim compiler, which is:
+Copyright (C) 2006-2023 Andreas Rumpf. All rights reserved.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+
+[ MIT license: http://www.opensource.org/licenses/mit-license.php ]

nimble.paths

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+--noNimblePath

nimph.nimble

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+# Package
+
+version       = "0.1"
+author        = "Jacek Sieka"
+description   = "Nim code formatter"
+license       = "MIT"
+srcDir        = "src"
+bin           = @["nimph"]
+
+# Dependencies
+
+# TODO https://github.com/nim-lang/nimble/issues/1166
+# Using exact version here and adding path manually :facepalm:
+# run `nimble setup -l` to hopefully make it work
+requires "nim == 2.0.0",
+         "compiler"
+
+proc build() =
+  exec "nim c --debuginfo -o:nimph src/nimph"
+
+task self, "Format nimph itself":
+  build()
+
+  # Stage changes before doing self-formatting!
+  exec "git diff --staged --no-ext-diff --quiet --exit-code"
+  exec "git add -A"
+
+  for file in listFiles("src"):
+    if file.len > 4 and file[^4..^1] == ".nim":
+      echo file
+      exec "./nimph " & file & " --debug"
+
+task f, "Format":
+  build()
+
+  cd "tests/before"
+  for file in listFiles("."):
+    if file.len > 4 and file[^4..^1] == ".nim":
+      echo file
+      exec "../../nimph " & file & " --outDir:../after --debug"