basic parsing

compiler/reporting/src/error/parse.rs

@@ -3238,6 +3238,31 @@ fn to_requires_report<'a>(
 
         ERequires::Space(error, row, col) => to_space_report(alloc, filename, &error, row, col),
 
+        ERequires::ListStart(row, col) => {
+            dbg!(row, col);
+            let surroundings = Region::from_rows_cols(start_row, start_col, row, col);
+            let region = Region::from_row_col(row, col);
+
+            let doc = alloc.stack(vec![
+                alloc.reflow(r"I am partway through parsing a header, but I got stuck here:"),
+                alloc.region_with_subregion(surroundings, region),
+                alloc.concat(vec![
+                    alloc.reflow("I am expecting the "),
+                    alloc.keyword("requires"),
+                    alloc.reflow(" keyword next, like "),
+                ]),
+                alloc
+                    .parser_suggestion("requires { main : Task I64 Str }")
+                    .indent(4),
+            ]);
+
+            Report {
+                filename,
+                doc,
+                title: "MISSING REQUIRES".to_string(),
+            }
+        }
+
         _ => todo!("unhandled parse error {:?}", parse_problem),
     }
 }