Rotating log file with retention

README.md

@@ -2,8 +2,8 @@
 
 `simple-log` is a small convenience layer on top of Racket's logging system.
 It provides generated procedures for the standard log levels and supports
-logging to the display, a file, custom callbacks, and a filterable in-memory
-store.
+logging to the display, regular or daily rotating files, custom callbacks, and
+a filterable in-memory store.
 
 ```racket
 #lang racket
@@ -31,3 +31,22 @@ Topic filters can select multiple topics or invert a match:
 
 The Scribble manual documents logger definitions, destinations, log levels,
 synchronization, and all in-memory store operations.
+## Rotating log files
+
+Daily rotation keeps the current log as plain text and gzip-compresses older
+days. The retention value counts the current day as well.
+
+```racket
+(sl-log-to-rotating-file "application.log")      ; 7 days
+(sl-log-to-rotating-file "application.log" 14)   ; 14 days
+```
+
+With a retention of 7 days the files look like this:
+
+```text
+application.log
+application.log.2026-08-28.gz
+application.log.2026-08-27.gz
+...
+```
+