Review comments

cli/tests/snapshot/snapshots/snapshot__eval_stderr_destructuring_closed_fail.ncl.snap

@@ -2,7 +2,7 @@
 source: cli/tests/snapshot/main.rs
 expression: err
 ---
-error: pattern binding failed
+error: destructuring failed
   ┌─ [INPUTS_PATH]/errors/destructuring_closed_fail.ncl:3:5
   │
 3 │ let {a} = {a=1, b=2}

core/src/error/mod.rs

@@ -1485,7 +1485,7 @@ impl IntoDiagnostics<FileId> for EvalError {
                     .push(secondary_term(&value, files).with_message("this value failed to match"));
 
                 vec![Diagnostic::error()
-                    .with_message("pattern binding failed")
+                    .with_message("destructuring failed")
                     .with_labels(labels)]
             }
             EvalError::IllegalPolymorphicTailAccess {

core/src/pretty.rs

@@ -864,9 +864,10 @@ where
             Lbl(_lbl) => allocator.text("%<label>").append(allocator.line()),
             Let(bindings, body, attrs) => docs![
                 allocator,
-                "let ",
+                "let",
+                allocator.space(),
                 if attrs.rec {
-                    allocator.text("rec ")
+                    docs![allocator, "rec", allocator.space()]
                 } else {
                     allocator.nil()
                 },
@@ -885,9 +886,10 @@ where
             .group(),
             LetPattern(bindings, body, attrs) => docs![
                 allocator,
-                "let ",
+                "let",
+                allocator.space(),
                 if attrs.rec {
-                    allocator.text("rec ")
+                    docs![allocator, "rec", allocator.space()]
                 } else {
                     allocator.nil()
                 },

core/src/term/mod.rs

@@ -2762,14 +2762,10 @@ pub mod make {
         T2: Into<RichTerm>,
         D: Into<Pattern>,
     {
-        let attrs = LetAttrs {
-            binding_type: BindingType::Normal,
-            rec: false,
-        };
         Term::LetPattern(
             std::iter::once((pat.into(), t1.into())).collect(),
             t2.into(),
-            attrs,
+            LetAttrs::default(),
         )
         .into()
     }

core/src/transform/desugar_destructuring.rs

@@ -34,18 +34,14 @@ pub fn transform_one(rt: RichTerm) -> RichTerm {
 pub fn desugar_fun(mut pat: Pattern, body: RichTerm) -> Term {
     let id = pat.alias.take().unwrap_or_else(LocIdent::fresh);
     let pos_body = body.pos;
-    let attrs = LetAttrs {
-        binding_type: BindingType::Normal,
-        rec: false,
-    };
 
     Term::Fun(
         id,
         RichTerm::new(
             Term::LetPattern(
                 std::iter::once((pat, Term::Var(id).into())).collect(),
                 body,
-                attrs,
+                LetAttrs::default(),
             ),
             // TODO: should we use rt.pos?
             pos_body,
@@ -87,8 +83,8 @@ pub fn desugar_fun(mut pat: Pattern, body: RichTerm) -> Term {
 ///
 /// There's some ambiguity about where to put the error-checking. It might be natural
 /// to put it before trying to access `%r1.foo`, but that would only raise the error
-/// if someone tries to evaluate `foo`. The place we've put it above puts the error
-/// check raises an error, for example, in `let 'Foo = 'Bar in true`.
+/// if someone tries to evaluate `foo`. Putting it in the body as above raises
+/// an error, for example, in `let 'Foo = 'Bar in true`.
 ///
 /// A recursive let-binding is desugared almost the same way, except that everything is
 /// shoved into a single let-rec block instead of three nested blocks.

doc/manual/syntax.md

@@ -937,7 +937,7 @@ Examples:
 [ 2, 3 ]
 
 > let 'Invalid x = {} in x
-error: pattern binding failed
+error: destructuring failed
 [...]
 ```