Format effectful arrows in annotations

roc-lang · Oct 15, 2024 · 2322960 · 2322960
1 parent 394a01f
commit 2322960
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Showing 2 changed files with 9 additions and 6 deletions.
diff --git a/crates/compiler/fmt/src/annotation.rs b/crates/compiler/fmt/src/annotation.rs
@@ -4,8 +4,8 @@ use crate::{
     Buf,
 };
 use roc_parse::ast::{
-    AbilityImpls, AssignedField, Collection, Expr, ExtractSpaces, ImplementsAbilities,
-    ImplementsAbility, ImplementsClause, Tag, TypeAnnotation, TypeHeader,
+    AbilityImpls, AssignedField, Collection, Expr, ExtractSpaces, FunctionArrow,
+    ImplementsAbilities, ImplementsAbility, ImplementsClause, Tag, TypeAnnotation, TypeHeader,
 };
 use roc_parse::ident::UppercaseIdent;
 use roc_region::all::Loc;
@@ -195,8 +195,7 @@ impl<'a> Formattable for TypeAnnotation<'a> {
         let self_is_multiline = self.is_multiline();
 
         match self {
-            Function(args, _arrow, ret) => {
-                // [purity-infrence] TODO: format arrow
+            Function(args, arrow, ret) => {
                 let needs_parens = parens != Parens::NotNeeded;
 
                 buf.indent(indent);
@@ -237,7 +236,11 @@ impl<'a> Formattable for TypeAnnotation<'a> {
                     buf.spaces(1);
                 }
 
-                buf.push_str("->");
+                match arrow {
+                    FunctionArrow::Pure => buf.push_str("->"),
+                    FunctionArrow::Effectful => buf.push_str("=>"),
+                }
+
                 buf.spaces(1);
 
                 ret.value

diff --git a/crates/compiler/test_syntax/tests/snapshots/pass/ann_effectful_fn.expr.formatted.roc b/crates/compiler/test_syntax/tests/snapshots/pass/ann_effectful_fn.expr.formatted.roc
@@ -1,4 +1,4 @@
-launchTheNukes : {} -> Result Bool LaunchNukeErr
+launchTheNukes : {} => Result Bool LaunchNukeErr
 launchTheNukes = \{} ->
     crash "todo"