Doc comments

generate/main.go

@@ -11,17 +11,18 @@ func readConfigGenerateAndWrite(configFilename string) error {
 		return err
 	}
 
+	code, err := Generate(config)
+	if err != nil {
+		return err
+	}
+
+	// Open out at the end -- decreases the chances we blank it if we err.
 	out, err := os.OpenFile(config.Generated, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0644)
 	if err != nil {
 		return fmt.Errorf("could not open generated file %v: %v",
 			config.Generated, err)
 	}
 
-	code, err := Generate(config)
-	if err != nil {
-		return err
-	}
-
 	_, err = out.Write(code)
 	return err
 }