more mention progress

Signed-off-by: William Casarin <jb55@jb55.com>

damus/Models/PostBlock.swift

@@ -0,0 +1,31 @@
+//
+//  PostBlock.swift
+//  damus
+//
+//  Created by William Casarin on 2022-05-07.
+//
+
+import Foundation
+
+enum PostBlock {
+    case text(String)
+    case ref(ReferencedId)
+    
+    var is_text: Bool {
+        if case .text = self {
+            return true
+        }
+        return false
+    }
+    
+    var is_ref: Bool {
+        if case .ref = self {
+            return true
+        }
+        return false
+    }
+}
+
+func parse_post_textblock(str: String, from: Int, to: Int) -> PostBlock {
+    return .text(String(substring(str, start: from, end: to)))
+}