fix(grainfmt): Correct formatting of nested constraints

grain-lang · Feb 13, 2025 · 2efb7f3 · 2efb7f3
1 parent e8a3ed2
commit 2efb7f3
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Showing 3 changed files with 18 additions and 4 deletions.
diff --git a/compiler/src/formatting/fmt.re b/compiler/src/formatting/fmt.re
@@ -2516,13 +2516,21 @@ let print_expression = (fmt, ~infix_wrap=d => group(indent(d)), expr) => {
          )
     | PExpConstraint(inner_expr, typ) =>
       (
-        switch (needs_grouping(~parent=expr, ~side=Left, inner_expr)) {
-        | ParenGrouping =>
+        switch (
+          inner_expr.pexp_desc,
+          needs_grouping(~parent=expr, ~side=Left, inner_expr),
+        ) {
+        | (PExpConstraint(_, _), typ) =>
+          parens(
+            indent(break ++ fmt.print_expression(fmt, inner_expr)) ++ break,
+          )
+        | (_, ParenGrouping) =>
           parens(
             indent(break ++ fmt.print_expression(fmt, inner_expr)) ++ break,
           )
-        | FormatterGrouping => group(fmt.print_expression(fmt, inner_expr))
-        | None => fmt.print_expression(fmt, inner_expr)
+        | (_, FormatterGrouping) =>
+          group(fmt.print_expression(fmt, inner_expr))
+        | (_, None) => fmt.print_expression(fmt, inner_expr)
         }
       )
       ++ string(":")

diff --git a/compiler/test/grainfmt/constraints.expected.gr b/compiler/test/grainfmt/constraints.expected.gr
@@ -8,3 +8,6 @@ let test = test => {
     print(i)
   }, test: List<Number>)
 }
+
+// Regression #2244
+(1: Number): Number
diff --git a/compiler/test/grainfmt/constraints.input.gr b/compiler/test/grainfmt/constraints.input.gr
@@ -8,3 +8,6 @@ let test = test => {
     print(i)
   }, test: List<Number>)
 }
+
+// Regression #2244
+(1: Number): Number