Add toLower / toUpper functions

Signed-off-by: Knut Ahlers <knut@ahlers.me>

msgformatter.go

@@ -16,6 +16,11 @@ func formatMessage(tplString string, m *irc.Message, r *rule, fields map[string]
 	// Create anonymous functions in current context in order to access function variables
 	messageFunctions := korvike.GetFunctionMap()
 
+	// Generic functions
+	messageFunctions["toLower"] = strings.ToLower
+	messageFunctions["toUpper"] = strings.ToUpper
+
+	// Message specific functions
 	messageFunctions["arg"] = func(arg int) (string, error) {
 		msgParts := strings.Split(m.Trailing(), " ")
 		if len(msgParts) <= arg {

wiki/Home.md

@@ -83,6 +83,8 @@ Additionally there are some functions available in the templates:
 - `group <idx>` - Gets matching group specified by index from `match_message` regular expression
 - `recentGame <username> [fallback]` - Returns the last played game name of the specified user (see shoutout example) or the `fallback` if the game could not be fetched. If no fallback was supplied the message will fail and not be sent.
 - `tag <tagname>` - Takes the message sent to the channel, returns the value of the tag specified
+- `toLower <string>` - Converts the given string to lower-case
+- `toUpper <string>` - Converts the given string to upper-case
 
 ## Command executions