adding params (#8)

src/lib.rs

@@ -65,7 +65,7 @@
 
 use core::fmt;
 use std::{
-    collections::VecDeque,
+    collections::{HashMap, VecDeque},
     future::Future,
     pin::Pin,
     sync::{
@@ -98,6 +98,10 @@ pub struct Message {
     /// The message itself.
     #[serde(rename = "m")]
     pub message: String,
+
+    /// adding extra args
+    #[serde(rename = "a")]
+    pub extra_args: HashMap<String, String>,
 }
 
 impl fmt::Display for Message {
@@ -106,6 +110,14 @@ impl fmt::Display for Message {
     }
 }
 
+impl Message {
+    /// adding extra arg to the message
+    pub fn add_arg(mut self, name: String, value: impl Into<String>) -> Self {
+        self.extra_args.insert(name, value.into());
+        self
+    }
+}
+
 type MessageQueue = VecDeque<Message>;
 
 /// Enumeration of message levels.
@@ -203,6 +215,8 @@ impl Messages {
             data.pending_messages.push_back(Message {
                 message: message.into(),
                 level,
+                // default initial value for extra args
+                extra_args: HashMap::new(),
             });
         }