diff --git a/class.puml b/class.puml
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+@startuml Class Diagram
+
+package core {
+    package str {
+        package traits {
+            interface FromStr<type Error> {
+                from_str(s: &str): Result<Self, Self::Error>
+            }
+        }
+    }
+}
+
+package cli {
+    package docstr {}
+    package schema {
+        +enum Cli {
+            +Play { PlayOpts }
+            +Export { ExportOptions }
+            +List { ListOptions }
+        }
+        +struct PlayOptions {
+            #input: FileContents
+        }
+        +struct ExportOptions {
+            ~input: FileContents
+            ~output: AudioFileName
+        }
+        +enum ListOptions {
+            +Extensions
+            +struct Math { -kind: Option<MathDocKind> }
+            +Glyphs
+        }
+        +enum MathDocKind {
+            +Functions
+            +Operators
+            +Literals
+        }
+        +struct FileContents {
+            0: String
+        }
+        FileContents --|> FromStr: type Error = io::Error
+        +struct AudioFileName {
+            0: String
+        }
+        +struct UnsupportedFileExtensionError {
+        }
+        AudioFileName -|> FromStr: type Error = UnsupportedFileExtensionError
+        Cli --> PlayOptions
+        Cli --> ExportOptions
+        Cli --> ListOptions
+        PlayOptions --> FileContents
+        ExportOptions -> FileContents
+        ExportOptions -> AudioFileName
+        ListOptions --> MathDocKind
+        AudioFileName --> UnsupportedFileExtensionError
+    }
+}
+package lang {}
+package dasp {}
+
+@enduml