Implement a suggestions mechanism

Each `Error` class now includes a set of suggestions, and these are printed by the top-level handler.
2022-03-07 10:09:09 +01:00
parent b09baf690b
commit c0792b1546
7 changed files with 191 additions and 6 deletions
@@ -74,8 +74,14 @@ std::pair<Value *, Pos> findAlongAttrPath(EvalState & state, const std::string &
                throw Error("empty attribute name in selection path '%1%'", attrPath);

            Bindings::iterator a = v->attrs->find(state.symbols.create(attr));
-            if (a == v->attrs->end())
-                throw AttrPathNotFound("attribute '%1%' in selection path '%2%' not found", attr, attrPath);
+            if (a == v->attrs->end()) {
+                std::set<std::string> attrNames;
+                for (auto & attr : *v->attrs)
+                    attrNames.insert(attr.name);
+
+                auto suggestions = Suggestions::bestMatches(attrNames, attr);
+                throw AttrPathNotFound(suggestions, "attribute '%1%' in selection path '%2%' not found", attr, attrPath);
+            }
            v = &*a->value;
            pos = *a->pos;
        }