Rework function declarations

src/Nixfmt/Pretty.hs

@@ -124,27 +124,33 @@ toLeading :: Maybe TrailingComment -> Trivia
 toLeading Nothing = []
 toLeading (Just (TrailingComment c)) = [LineComment (" " <> c)]
 
-prettyComma :: Maybe Leaf -> Doc
-prettyComma Nothing = mempty
-prettyComma (Just comma) = softline' <> pretty comma <> hardspace
-
 instance Pretty ParamAttr where
-    pretty (ParamAttr name Nothing comma)
-        = pretty name <> prettyComma comma
+    -- Simple parameter
+    pretty (ParamAttr name Nothing maybeComma)
+        = pretty name <> (fromMaybe (text ",") (fmap pretty maybeComma)) <> softline
 
+    -- With ? default
     pretty (ParamAttr name (Just (qmark, def)) comma)
         = group (pretty name <> hardspace <> pretty qmark
             <> absorb softline mempty (Just 2) def)
-            <> prettyComma comma
+            <> pretty comma <> softline
 
+    -- ...
     pretty (ParamEllipsis ellipsis)
         = pretty ellipsis
 
 instance Pretty Parameter where
+    -- param:
     pretty (IDParameter i) = pretty i
+
+    -- {}:
+    pretty (SetParameter bopen [] bclose)
+        = group $ pretty bopen <> hardspace <> pretty bclose
+
+    -- { stuff }:
     pretty (SetParameter bopen attrs bclose)
-        = group $ pretty bopen <> hardspace
-                  <> hcat attrs <> softline
+        = group $ pretty bopen <> hardline
+                  <> nest 2 (sepBy hardline attrs) <> hardline
                   <> pretty bclose
 
     pretty (ContextParameter param1 at param2)

test/diff/apply/out.nix

@@ -56,7 +56,9 @@
   }
   # https://github.com/kamadorueda/alejandra/issues/372#issuecomment-1435083516
   {
-    outputs = { utils }:
+    outputs = {
+        utils,
+      }:
       # For each supported platform,
       utils.lib.eachDefaultSystem (system: { });
   }

test/diff/comment/out.nix

@@ -73,8 +73,9 @@
     #7
   in d)
 
-  ({ a, # comment
-    b ? 2, # comment
+  ({
+      a, # comment
+      b ? 2, # comment
     }:
     _)
 ]

test/diff/idioms_lib_2/out.nix

@@ -1,4 +1,6 @@
-{ lib }:
+{
+  lib,
+}:
 
 rec {
 

test/diff/idioms_lib_3/out.nix

@@ -12,7 +12,9 @@
 #
 # Tests can be found in ./tests/misc.nix
 # Documentation in the manual, #sec-generators
-{ lib, }:
+{
+  lib,
+}:
 with (lib).trivial;
 let
   libStr = lib.strings;
@@ -75,7 +77,9 @@ in rec {
   #
   # mkKeyValueDefault {} ":" "f:oo" "bar"
   # > "f\:oo:bar"
-  mkKeyValueDefault = { mkValueString ? mkValueStringDefault { } }:
+  mkKeyValueDefault = {
+      mkValueString ? mkValueStringDefault { }
+    }:
     sep: k: v:
     "${libStr.escape [ sep ] k}${sep}${mkValueString v}";
 
@@ -84,8 +88,10 @@ in rec {
   # Generate a key-value-style config file from an attrset.
   #
   # mkKeyValue is the same as in toINI.
-  toKeyValue =
-    { mkKeyValue ? mkKeyValueDefault { } "=", listsAsDuplicateKeys ? false }:
+  toKeyValue = {
+      mkKeyValue ? mkKeyValueDefault { } "=",
+      listsAsDuplicateKeys ? false
+    }:
     let
       mkLine = k: v: mkKeyValue k v + "\n";
       mkLines = if listsAsDuplicateKeys then
@@ -117,11 +123,12 @@ in rec {
   # For more examples see the test cases in ./tests/misc.nix.
   toINI = {
     # apply transformations (e.g. escapes) to section names
-    mkSectionName ? (name: libStr.escape [ "[" "]" ] name),
-    # format a setting line from key and value
-    mkKeyValue ? mkKeyValueDefault { } "=",
-    # allow lists as values for duplicate keys
-    listsAsDuplicateKeys ? false }:
+      mkSectionName ? (name: libStr.escape [ "[" "]" ] name),
+      # format a setting line from key and value
+      mkKeyValue ? mkKeyValueDefault { } "=",
+      # allow lists as values for duplicate keys
+      listsAsDuplicateKeys ? false
+    }:
     attrsOfAttrs:
     let
       # map function to string for each key val
@@ -166,12 +173,16 @@ in rec {
   # the part in `sections`.
   toINIWithGlobalSection = {
     # apply transformations (e.g. escapes) to section names
-    mkSectionName ? (name: libStr.escape [ "[" "]" ] name),
-    # format a setting line from key and value
-    mkKeyValue ? mkKeyValueDefault { } "=",
-    # allow lists as values for duplicate keys
-    listsAsDuplicateKeys ? false }:
-    { globalSection, sections, }:
+      mkSectionName ? (name: libStr.escape [ "[" "]" ] name),
+      # format a setting line from key and value
+      mkKeyValue ? mkKeyValueDefault { } "=",
+      # allow lists as values for duplicate keys
+      listsAsDuplicateKeys ? false
+    }:
+    {
+      globalSection,
+      sections,
+    }:
     (if globalSection == { } then
       ""
     else
@@ -247,9 +258,11 @@ in rec {
 
   withRecursion = {
     # If this option is not null, the given value will stop evaluating at a certain depth
-    depthLimit
-    # If this option is true, an error will be thrown, if a certain given depth is exceeded
-    , throwOnDepthLimit ? true }:
+      depthLimit
+      # If this option is true, an error will be thrown, if a certain given depth is exceeded
+      ,
+      throwOnDepthLimit ? true
+    }:
     assert builtins.isInt depthLimit;
     let
       specialAttrs = [ "__functor" "__functionArgs" "__toString" "__pretty" ];
@@ -286,11 +299,12 @@ in rec {
        will use fn to convert val to a pretty printed representation.
        (This means fn is type Val -> String.)
     */
-    allowPrettyValues ? false,
-    # If this option is true, the output is indented with newlines for attribute sets and lists
-    multiline ? true,
-    # Initial indentation level
-    indent ? "" }:
+      allowPrettyValues ? false,
+      # If this option is true, the output is indented with newlines for attribute sets and lists
+      multiline ? true,
+      # Initial indentation level
+      indent ? ""
+    }:
     let
       go = indent: v:
         with builtins;

test/diff/idioms_nixos_1/out.nix

@@ -1,4 +1,9 @@
-{ config, lib, pkgs, ... }:
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
 
 with lib;
 

test/diff/idioms_pkgs_1/out.nix

@@ -1,4 +1,9 @@
-{ stdenv, lib, fetchFrom, ... }:
+{
+  stdenv,
+  lib,
+  fetchFrom,
+  ...
+}:
 
 stdenv.mkDerivation rec {
   pname = "test";

test/diff/idioms_pkgs_2/out.nix

@@ -1,4 +1,12 @@
-{ lib, stdenv, fetchurl, nixos, testVersion, testEqualDerivation, hello }:
+{
+  lib,
+  stdenv,
+  fetchurl,
+  nixos,
+  testVersion,
+  testEqualDerivation,
+  hello,
+}:
 
 stdenv.mkDerivation rec {
   pname = "hello";

test/diff/idioms_pkgs_3/out.nix

@@ -1,4 +1,9 @@
-{ config, lib, pkgs, ... }:
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
 
 with lib;
 

test/diff/key_value/out.nix

@@ -54,7 +54,11 @@ rec {
       c = 2;
     };
   n = pkgs: { };
-  o = { pkgs, ... }: { };
+  o = {
+      pkgs,
+      ...
+    }:
+    { };
 
   a
   # b

test/diff/lambda/out.nix

@@ -19,25 +19,44 @@
   (aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa)
   (aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa:
     aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa)
-  ({ pkgs ? import ./.. { }, locationsXml }: null)
+  ({
+      pkgs ? import ./.. { },
+      locationsXml,
+    }:
+    null)
   (a: b: c: { }: a: b: c: a)
 
-  ({ pkgs, ... }:
+  ({
+      pkgs,
+      ...
+    }:
     {
       # Stuff
     })
 
-  ({ pkgs, ... }: let in pkgs)
+  ({
+      pkgs,
+      ...
+    }:
+    let
+    in pkgs)
 
   (a:
-    { b, ... }:
+    {
+      b,
+      ...
+    }:
     c:
     {
       # Stuff
     })
 
   (a:
-    { b, c, ... }:
+    {
+      b,
+      c,
+      ...
+    }:
     d:
     {
       # Stuff