Add Julia formatter (#230)

This formatter uses a script wrapping the [JuliaFormatter.jl library](https://github.com/domluna/JuliaFormatter.jl).  This "formatter script in the plugin" approach hasn't been taken before in `vim-codefmt`, so let me know if you'd prefer a different approach or to reorganize things.  (The JuliaFormatter.jl library ships with an executable script, but it only works on file paths (not stdin) and can't handle line ranges.  I'm also not sure how to get the path of a bin directory in your Julia environment, which doesn't work like executables in a package management system like npm.)

If the user hasn't installed the `JuliaFormatter` package, instructions will point to an `install` script in the same directory as the formatter script.  I've tested the shell version of this script, but don't have a Windows machine to test the `.cmd` version.

The line-range handling is a bit of a hack: the underlying library doesn't expose this functionality, so I used comments to enable/disable the formatter around relevant blocks.  I found some edge case behaviors that I've hopefully documented clearly.

The script will use the same `.JuliaFormatter.toml` files in the parent directory hierarchy of the source file being edited to determine the formatter options like style, indent, and line width.  This is the same behavior that running the executable from JuliaFormatter.

autoload/codefmt/juliaformatter.vim

@@ -0,0 +1,76 @@
+" Copyright 2023 Google LLC
+"
+" Licensed under the Apache License, Version 2.0 (the "License");
+" you may not use this file except in compliance with the License.
+" You may obtain a copy of the License at
+"
+"     http://www.apache.org/licenses/LICENSE-2.0
+"
+" Unless required by applicable law or agreed to in writing, software
+" distributed under the License is distributed on an "AS IS" BASIS,
+" WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+" See the License for the specific language governing permissions and
+" limitations under the License.
+
+let s:plugin = maktaba#plugin#Get('codefmt')
+
+let s:checkedInstall = 0
+
+""
+" @private
+" Formatter: JuliaFormatter
+function! codefmt#juliaformatter#GetFormatter() abort
+  let l:installer =
+        \ maktaba#path#Join([s:plugin.location, 'bin', 'julia', 'install'])
+  let l:formatter = {
+        \ 'name': 'JuliaFormatter', 'setup_instructions': 'Run ' . l:installer}
+
+  function l:formatter.IsAvailable() abort
+    let l:cmd = codefmt#formatterhelpers#ResolveFlagToArray('julia_format_executable')
+    if codefmt#ShouldPerformIsAvailableChecks()
+      if !executable(l:cmd[0])
+       return 0
+     endif
+     if !s:checkedInstall
+       let s:checkedInstall = 1
+       let l:syscall = maktaba#syscall#Create([cmd[0], "--check-install"])
+       call l:syscall.Call(0)
+       if v:shell_error != 0
+         return 0
+       endif
+     endif
+    endif
+    return 1
+  endfunction
+
+  function l:formatter.AppliesToBuffer() abort
+    return codefmt#formatterhelpers#FiletypeMatches(&filetype, 'julia')
+  endfunction
+
+  ""
+  " Reformat the current buffer using formatjulia.jl, only targeting {ranges}.
+  function l:formatter.FormatRanges(ranges) abort
+    if empty(a:ranges)
+      return
+    endif
+    for [l:startline, l:endline] in a:ranges
+      call maktaba#ensure#IsNumber(l:startline)
+      call maktaba#ensure#IsNumber(l:endline)
+    endfor
+    let l:exec = s:plugin.Flag('julia_format_executable')
+    if empty(l:exec)
+      let l:cmd = [maktaba#path#Join(
+            \ [s:plugin.location, 'bin', 'julia', 'formatjulia.jl'])]
+    else
+      " Split the command on spaces, unless preceeded by a backslash
+      let l:cmd = split(l:exec, '\\\@<! ')
+    endif
+    " JuliaFormatter looks up .JuliaFormatter.toml settings based on file tree
+    let l:cmd += ['--file-path', @%]
+    let l:cmd += ['--lines']
+    let l:cmd += maktaba#function#Map(a:ranges, {x -> x[0] . ':' . x[1]})
+    call codefmt#formatterhelpers#Format(l:cmd)
+  endfunction
+
+  return l:formatter
+endfunction

bin/julia/.JuliaFormatter.toml

@@ -0,0 +1,18 @@
+# Copyright 2023 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+indent = 2
+margin = 80
+trailing_comma = false
+whitespace_in_kwargs = false

bin/julia/Manifest.toml

@@ -0,0 +1,232 @@
+# This file is machine-generated - editing it directly is not advised
+
+julia_version = "1.9.3"
+manifest_format = "2.0"
+project_hash = "93e024a7bf6c9615a79c4b80b3a014b0f1f744c9"
+
+[[deps.ArgParse]]
+deps = ["Logging", "TextWrap"]
+git-tree-sha1 = "3102bce13da501c9104df33549f511cd25264d7d"
+uuid = "c7e460c6-2fb9-53a9-8c5b-16f535851c63"
+version = "1.1.4"
+
+[[deps.ArgTools]]
+uuid = "0dad84c5-d112-42e6-8d28-ef12dabb789f"
+version = "1.1.1"
+
+[[deps.Artifacts]]
+uuid = "56f22d72-fd6d-98f1-02f0-08ddc0907c33"
+
+[[deps.Base64]]
+uuid = "2a0f44e3-6c83-55bd-87e4-b1978d98bd5f"
+
+[[deps.CSTParser]]
+deps = ["Tokenize"]
+git-tree-sha1 = "3ddd48d200eb8ddf9cb3e0189fc059fd49b97c1f"
+uuid = "00ebfdb7-1f24-5e51-bd34-a7502290713f"
+version = "3.3.6"
+
+[[deps.CommonMark]]
+deps = ["Crayons", "JSON", "PrecompileTools", "URIs"]
+git-tree-sha1 = "532c4185d3c9037c0237546d817858b23cf9e071"
+uuid = "a80b9123-70ca-4bc0-993e-6e3bcb318db6"
+version = "0.8.12"
+
+[[deps.Compat]]
+deps = ["UUIDs"]
+git-tree-sha1 = "8a62af3e248a8c4bad6b32cbbe663ae02275e32c"
+uuid = "34da2185-b29b-5c13-b0c7-acf172513d20"
+version = "4.10.0"
+
+    [deps.Compat.extensions]
+    CompatLinearAlgebraExt = "LinearAlgebra"
+
+    [deps.Compat.weakdeps]
+    Dates = "ade2ca70-3891-5945-98fb-dc099432e06a"
+    LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
+
+[[deps.Crayons]]
+git-tree-sha1 = "249fe38abf76d48563e2f4556bebd215aa317e15"
+uuid = "a8cc5b0e-0ffa-5ad4-8c14-923d3ee1735f"
+version = "4.1.1"
+
+[[deps.DataStructures]]
+deps = ["Compat", "InteractiveUtils", "OrderedCollections"]
+git-tree-sha1 = "3dbd312d370723b6bb43ba9d02fc36abade4518d"
+uuid = "864edb3b-99cc-5e75-8d2d-829cb0a9cfe8"
+version = "0.18.15"
+
+[[deps.Dates]]
+deps = ["Printf"]
+uuid = "ade2ca70-3891-5945-98fb-dc099432e06a"
+
+[[deps.Downloads]]
+deps = ["ArgTools", "FileWatching", "LibCURL", "NetworkOptions"]
+uuid = "f43a241f-c20a-4ad4-852c-f6b1247861c6"
+version = "1.6.0"
+
+[[deps.FileWatching]]
+uuid = "7b1f6079-737a-58dc-b8bc-7a2ca5c1b5ee"
+
+[[deps.Glob]]
+git-tree-sha1 = "97285bbd5230dd766e9ef6749b80fc617126d496"
+uuid = "c27321d9-0574-5035-807b-f59d2c89b15c"
+version = "1.3.1"
+
+[[deps.InteractiveUtils]]
+deps = ["Markdown"]
+uuid = "b77e0a4c-d291-57a0-90e8-8db25a27a240"
+
+[[deps.JSON]]
+deps = ["Dates", "Mmap", "Parsers", "Unicode"]
+git-tree-sha1 = "31e996f0a15c7b280ba9f76636b3ff9e2ae58c9a"
+uuid = "682c06a0-de6a-54ab-a142-c8b1cf79cde6"
+version = "0.21.4"
+
+[[deps.JuliaFormatter]]
+deps = ["CSTParser", "CommonMark", "DataStructures", "Glob", "Pkg", "PrecompileTools", "Tokenize"]
+git-tree-sha1 = "3d5b5b539e4606dcca0e6a467b98a64c8da4850b"
+uuid = "98e50ef6-434e-11e9-1051-2b60c6c9e899"
+version = "1.0.42"
+
+[[deps.LibCURL]]
+deps = ["LibCURL_jll", "MozillaCACerts_jll"]
+uuid = "b27032c2-a3e7-50c8-80cd-2d36dbcbfd21"
+version = "0.6.3"
+
+[[deps.LibCURL_jll]]
+deps = ["Artifacts", "LibSSH2_jll", "Libdl", "MbedTLS_jll", "Zlib_jll", "nghttp2_jll"]
+uuid = "deac9b47-8bc7-5906-a0fe-35ac56dc84c0"
+version = "7.84.0+0"
+
+[[deps.LibGit2]]
+deps = ["Base64", "NetworkOptions", "Printf", "SHA"]
+uuid = "76f85450-5226-5b5a-8eaa-529ad045b433"
+
+[[deps.LibSSH2_jll]]
+deps = ["Artifacts", "Libdl", "MbedTLS_jll"]
+uuid = "29816b5a-b9ab-546f-933c-edad1886dfa8"
+version = "1.10.2+0"
+
+[[deps.Libdl]]
+uuid = "8f399da3-3557-5675-b5ff-fb832c97cbdb"
+
+[[deps.Logging]]
+uuid = "56ddb016-857b-54e1-b83d-db4d58db5568"
+
+[[deps.Markdown]]
+deps = ["Base64"]
+uuid = "d6f4376e-aef5-505a-96c1-9c027394607a"
+
+[[deps.MbedTLS_jll]]
+deps = ["Artifacts", "Libdl"]
+uuid = "c8ffd9c3-330d-5841-b78e-0817d7145fa1"
+version = "2.28.2+0"
+
+[[deps.Mmap]]
+uuid = "a63ad114-7e13-5084-954f-fe012c677804"
+
+[[deps.MozillaCACerts_jll]]
+uuid = "14a3606d-f60d-562e-9121-12d972cd8159"
+version = "2022.10.11"
+
+[[deps.NetworkOptions]]
+uuid = "ca575930-c2e3-43a9-ace4-1e988b2c1908"
+version = "1.2.0"
+
+[[deps.OrderedCollections]]
+git-tree-sha1 = "2e73fe17cac3c62ad1aebe70d44c963c3cfdc3e3"
+uuid = "bac558e1-5e72-5ebc-8fee-abe8a469f55d"
+version = "1.6.2"
+
+[[deps.Parsers]]
+deps = ["Dates", "PrecompileTools", "UUIDs"]
+git-tree-sha1 = "716e24b21538abc91f6205fd1d8363f39b442851"
+uuid = "69de0a69-1ddd-5017-9359-2bf0b02dc9f0"
+version = "2.7.2"
+
+[[deps.Pkg]]
+deps = ["Artifacts", "Dates", "Downloads", "FileWatching", "LibGit2", "Libdl", "Logging", "Markdown", "Printf", "REPL", "Random", "SHA", "Serialization", "TOML", "Tar", "UUIDs", "p7zip_jll"]
+uuid = "44cfe95a-1eb2-52ea-b672-e2afdf69b78f"
+version = "1.9.2"
+
+[[deps.PrecompileTools]]
+deps = ["Preferences"]
+git-tree-sha1 = "03b4c25b43cb84cee5c90aa9b5ea0a78fd848d2f"
+uuid = "aea7be01-6a6a-4083-8856-8a6e6704d82a"
+version = "1.2.0"
+
+[[deps.Preferences]]
+deps = ["TOML"]
+git-tree-sha1 = "00805cd429dcb4870060ff49ef443486c262e38e"
+uuid = "21216c6a-2e73-6563-6e65-726566657250"
+version = "1.4.1"
+
+[[deps.Printf]]
+deps = ["Unicode"]
+uuid = "de0858da-6303-5e67-8744-51eddeeeb8d7"
+
+[[deps.REPL]]
+deps = ["InteractiveUtils", "Markdown", "Sockets", "Unicode"]
+uuid = "3fa0cd96-eef1-5676-8a61-b3b8758bbffb"
+
+[[deps.Random]]
+deps = ["SHA", "Serialization"]
+uuid = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
+
+[[deps.SHA]]
+uuid = "ea8e919c-243c-51af-8825-aaa63cd721ce"
+version = "0.7.0"
+
+[[deps.Serialization]]
+uuid = "9e88b42a-f829-5b0c-bbe9-9e923198166b"
+
+[[deps.Sockets]]
+uuid = "6462fe0b-24de-5631-8697-dd941f90decc"
+
+[[deps.TOML]]
+deps = ["Dates"]
+uuid = "fa267f1f-6049-4f14-aa54-33bafae1ed76"
+version = "1.0.3"
+
+[[deps.Tar]]
+deps = ["ArgTools", "SHA"]
+uuid = "a4e569a6-e804-4fa4-b0f3-eef7a1d5b13e"
+version = "1.10.0"
+
+[[deps.TextWrap]]
+git-tree-sha1 = "9250ef9b01b66667380cf3275b3f7488d0e25faf"
+uuid = "b718987f-49a8-5099-9789-dcd902bef87d"
+version = "1.0.1"
+
+[[deps.Tokenize]]
+git-tree-sha1 = "0454d9a9bad2400c7ccad19ca832a2ef5a8bc3a1"
+uuid = "0796e94c-ce3b-5d07-9a54-7f471281c624"
+version = "0.5.26"
+
+[[deps.URIs]]
+git-tree-sha1 = "67db6cc7b3821e19ebe75791a9dd19c9b1188f2b"
+uuid = "5c2747f8-b7ea-4ff2-ba2e-563bfd36b1d4"
+version = "1.5.1"
+
+[[deps.UUIDs]]
+deps = ["Random", "SHA"]
+uuid = "cf7118a7-6976-5b1a-9a39-7adc72f591a4"
+
+[[deps.Unicode]]
+uuid = "4ec0a83e-493e-50e2-b9ac-8f72acf5a8f5"
+
+[[deps.Zlib_jll]]
+deps = ["Libdl"]
+uuid = "83775a58-1f1d-513f-b197-d71354ab007a"
+version = "1.2.13+0"
+
+[[deps.nghttp2_jll]]
+deps = ["Artifacts", "Libdl"]
+uuid = "8e850ede-7688-5339-a07c-302acd2aaf8d"
+version = "1.48.0+0"
+
+[[deps.p7zip_jll]]
+deps = ["Artifacts", "Libdl"]
+uuid = "3f19e933-33d8-53b3-aaab-bd5110c3b7a0"
+version = "17.4.0+0"

bin/julia/Project.toml

@@ -0,0 +1,8 @@
+name = "julia"
+uuid = "f7e72769-0d4f-4e1c-bb39-275b23f83607"
+authors = ["Trevor Stone <github@trevorstone.org>"]
+version = "0.1.0"
+
+[deps]
+ArgParse = "c7e460c6-2fb9-53a9-8c5b-16f535851c63"
+JuliaFormatter = "98e50ef6-434e-11e9-1051-2b60c6c9e899"