fix: defer assignment visited to avoid unstable outcome

Author: Hoblovski

lang/collect/export.go

@@ -161,37 +161,40 @@ func (c *Collector) exportSymbol(repo *uniast.Repository, symbol *DocumentSymbol
 		return id, nil
 	}
 
-	name := symbol.Name
-	if name == "" {
-		if refName == "" {
-			e = fmt.Errorf("both symbol %v name and refname is empty", symbol)
-			return
-		}
-		// NOTICE: use refName as id when symbol name is missing
-		name = refName
-	}
+	// Check NeedStdSymbol
 	file := symbol.Location.URI.File()
 	mod, path, err := c.spec.NameSpace(file)
 	if err != nil {
 		e = err
 		return
 	}
-
 	if !c.NeedStdSymbol && mod == "" {
 		e = ErrStdSymbol
 		return
 	}
 
-	tmp := uniast.NewIdentity(mod, path, name)
-	id = &tmp
-	visited[symbol] = id
-
-	// Load eternal symbol on demands
+	// Load external symbol on demands
 	if !c.LoadExternalSymbol && (!c.internal(symbol.Location) || symbol.Kind == SKUnknown) {
 		e = ErrExternalSymbol
 		return
 	}
 
+	// Construct Identity and save to visited
+	name := symbol.Name
+	if name == "" {
+		if refName == "" {
+			e = fmt.Errorf("both symbol %v name and refname is empty", symbol)
+			return
+		}
+		// NOTICE: use refName as id when symbol name is missing
+		name = refName
+	}
+	tmp := uniast.NewIdentity(mod, path, name)
+	id = &tmp
+	// Save to visited ONLY WHEN no errors occur
+	visited[symbol] = id
+
+	// Walk down from repo struct
 	if repo.Modules[mod] == nil {
 		repo.Modules[mod] = newModule(mod, "", c.Language)
 	}