Debug ProcLayouts

crates/compiler/mono/src/ir.rs

@@ -3933,6 +3933,33 @@ impl<'a> ProcLayout<'a> {
             }
         }
     }
+
+    pub fn dbg_deep<'r, I: LayoutInterner<'a>>(&self, interner: &'r I) -> DbgProcLayout<'a, 'r, I> {
+        DbgProcLayout {
+            layout: *self,
+            interner,
+        }
+    }
+}
+
+pub struct DbgProcLayout<'a, 'r, I: LayoutInterner<'a>> {
+    layout: ProcLayout<'a>,
+    interner: &'r I,
+}
+
+impl<'a, 'r, I: LayoutInterner<'a>> std::fmt::Debug for DbgProcLayout<'a, 'r, I> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let ProcLayout {
+            arguments,
+            result,
+            niche,
+        } = self.layout;
+        f.debug_struct("ProcLayout")
+            .field("arguments", &self.interner.dbg_deep_iter(arguments))
+            .field("result", &self.interner.dbg_deep(result))
+            .field("niche", &niche.dbg_deep(self.interner))
+            .finish()
+    }
 }
 
 fn specialize_naked_symbol<'a>(

crates/compiler/mono/src/layout.rs

@@ -1313,6 +1313,14 @@ impl<'a> Niche<'a> {
             ]),
         }
     }
+
+    pub fn dbg_deep<'r, I: LayoutInterner<'a>>(
+        &'r self,
+        interner: &'r I,
+    ) -> crate::layout::intern::dbg::DbgFields<'a, 'r, I> {
+        let NichePriv::Captures(caps) = &self.0;
+        interner.dbg_deep_iter(caps)
+    }
 }
 
 #[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]

crates/compiler/mono/src/layout/intern.rs

@@ -365,6 +365,10 @@ pub trait LayoutInterner<'a>: Sized {
     fn dbg_deep<'r>(&'r self, layout: InLayout<'a>) -> dbg::Dbg<'a, 'r, Self> {
         dbg::Dbg(self, layout)
     }
+
+    fn dbg_deep_iter<'r>(&'r self, layouts: &'a [InLayout<'a>]) -> dbg::DbgFields<'a, 'r, Self> {
+        dbg::DbgFields(self, layouts)
+    }
 }
 
 /// An interned layout.
@@ -1274,7 +1278,7 @@ mod equiv {
     }
 }
 
-mod dbg {
+pub mod dbg {
     use roc_module::symbol::Symbol;
 
     use crate::layout::{Builtin, LambdaSet, Layout, UnionLayout};
@@ -1311,7 +1315,7 @@ mod dbg {
         }
     }
 
-    struct DbgFields<'a, 'r, I: LayoutInterner<'a>>(&'r I, &'a [InLayout<'a>]);
+    pub struct DbgFields<'a, 'r, I: LayoutInterner<'a>>(pub &'r I, pub &'a [InLayout<'a>]);
 
     impl<'a, 'r, I: LayoutInterner<'a>> std::fmt::Debug for DbgFields<'a, 'r, I> {
         fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {