Implement correct printing for fast pipe sugar (#2087)

* Implement correct printing for fast pipe sugar
+ make sure uncurried expressions are formatted correctly
under fast pipe sugar

* remove unused code

* Fix unit sugar + add test

* improve naming of anonymous function arg which formats the pipe segments

formatTest/unit_tests/expected_output/fastPipe.re

@@ -2,13 +2,32 @@ foo->f->g->h;
 
 bar->f->g->h;
 
+foo(g)->f(a, b)->g(c, d);
+
+foo->f();
+
 compilation
 ->Plugin.buildAssets
 ->Js.Json.stringify
-->Node.Fs.writeFileAsUtf8Sync(
-  _,
-  path,
-);
+->Node.Fs.writeFileAsUtf8Sync(_, path);
+
+foo
+->someLongIdentifier
+->otherLongIdentifierWithArgs(a, b, c)
+->longIdentWithVeryLongArgs(
+    aaaaaaaaaaaaaaaaaaaaa,
+    bbbbbbbbbbbbbbbb,
+    ccccccccccccc,
+  );
+
+/* with comments */
+compilation
+/* first */
+->Plugin.buildAssets /* first trail */
+/* second */
+->Js.Json.stringify /* second trail */
+/* last */
+->Node.Fs.writeFileAsUtf8Sync(_, path); /* last trail */
 
 foo->bar->baz >>= monadicFunction |> bind;
 
@@ -77,3 +96,10 @@ location##streets.foo[1];
 (event->target^)##value;
 
 event->target^ #= value;
+
+foo->f(. a, b);
+foo->f(. a, b)->g(. c, d);
+foo->([@attr] f(. a, b))->([@attr2] f(. a, b));
+foo->f(.);
+foo->f(.)->g(.);
+foo->([@attr] f(.))->([@attr] g(.));

formatTest/unit_tests/input/fastPipe.re

@@ -2,11 +2,29 @@ foo |. f |. g |. h;
 
 bar->f->g->h;
 
+foo(g)->f(a, b)->g(c, d);
+
+foo->f();
+
 compilation
 ->Plugin.buildAssets
 ->Js.Json.stringify
 ->Node.Fs.writeFileAsUtf8Sync(_, path);
 
+foo
+->someLongIdentifier
+->otherLongIdentifierWithArgs(a, b, c)
+->longIdentWithVeryLongArgs(aaaaaaaaaaaaaaaaaaaaa, bbbbbbbbbbbbbbbb, ccccccccccccc);
+
+/* with comments */
+compilation
+/* first */
+->Plugin.buildAssets /* first trail */
+/* second */
+->Js.Json.stringify /* second trail */
+/* last */
+->Node.Fs.writeFileAsUtf8Sync(_, path); /* last trail */
+
 foo->bar->baz >>= monadicFunction |> bind;
 
 compilation
@@ -78,3 +96,10 @@ event->target##(value(foo));
 (event->target^)##value;
 
 event->target^ #= value;
+
+foo->f(. a, b);
+foo->f(. a, b)->g(. c, d);
+foo->([@attr] f(. a, b))->([@attr2] f(. a, b));
+foo->f(.);
+foo->f(.)->g(.);
+foo->([@attr] f(.))->([@attr] g(.));

src/reason-parser/jbuild

@@ -53,7 +53,6 @@
   (wrapped false)
   (modules
    (lexer_warning
-    reason_ast
     reason_syntax_util
     reason_comment
     reason_layout

src/reason-parser/reason_heuristics.ml

@@ -95,3 +95,11 @@ let isUnderscoreIdent expr =
   match Ast_404.Parsetree.(expr.pexp_desc) with
   | Pexp_ident ({txt = Lident "_"}) -> true
   | _ -> false
+
+let isFastPipe e = match Ast_404.Parsetree.(e.pexp_desc) with
+  | Pexp_ident({txt = Longident.Lident("|.")}) -> true
+  | Pexp_apply(
+      {pexp_desc = Pexp_ident({txt = Longident.Lident("|.")})},
+      _
+    ) -> true
+  | _ -> false