From 5c53bb9e9feaf3e0579e6fbbf2650f116e3a214d Mon Sep 17 00:00:00 2001
From: Robert Bendun <rob.bendun@gmail.com>
Date: Sun, 21 Aug 2022 20:39:35 +0200
Subject: [PATCH] Nicer undefiend operator message

---
 src/errors.cc | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/src/errors.cc b/src/errors.cc
index 35ae955..966e6af 100644
--- a/src/errors.cc
+++ b/src/errors.cc
@@ -317,6 +317,27 @@ std::ostream& operator<<(std::ostream& os, Error const& err)
 			os << '\n';
 
 			print_error_line(loc);
+
+			static constexpr auto Operators = std::array {
+				"and", "or",
+				"==", "!=", "<", ">", "<=", ">=",
+				"+", "+=", "-", "-=", "*", "*=", "/", "/=",
+				"&", "&=", "."
+			};
+
+			os << pretty::begin_comment;
+			os << "Operators that look familiar to one above:\n";
+			os << "  ";
+
+			for (auto op : Operators) {
+				for (auto c : err.op) {
+					if (std::string_view(op).find(c) != std::string_view::npos) {
+						os << op << ' ';
+						break;
+					}
+				}
+			}
+			os << '\n' << pretty::end;
 		},
 		[&](errors::Unexpected_Keyword const&)               { unimplemented(); },
 	}, err.details);