Unify WASM and Rust API types

src/types/cursor_position.rs

@@ -0,0 +1,36 @@
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+#[cfg(feature = "wasm")]
+use wasm_bindgen::prelude::*;
+
+// CursorPosition represents the position of an identifiable cursor in a text
+// document based on its (UTF-8) character index.
+#[cfg_attr(feature = "wasm", wasm_bindgen)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[derive(Debug, Clone, PartialEq, Default)]
+pub struct CursorPosition {
+    pub id: usize,
+    pub char_index: usize,
+}
+
+#[cfg_attr(feature = "wasm", wasm_bindgen)]
+impl CursorPosition {
+    #[cfg_attr(feature = "wasm", wasm_bindgen(constructor))]
+    #[must_use]
+    pub fn new(id: usize, char_index: usize) -> Self { Self { id, char_index } }
+
+    #[must_use]
+    pub fn with_index(&self, index: usize) -> Self {
+        CursorPosition {
+            id: self.id,
+            char_index: index,
+        }
+    }
+
+    #[must_use]
+    pub fn id(&self) -> usize { self.id }
+
+    #[cfg_attr(feature = "wasm", wasm_bindgen(js_name = characterPosition))]
+    #[must_use]
+    pub fn char_index(&self) -> usize { self.char_index }
+}

src/types/text_with_cursors.rs

@@ -0,0 +1,47 @@
+#[cfg(feature = "wasm")]
+use wasm_bindgen::prelude::*;
+
+use crate::types::cursor_position::CursorPosition;
+
+#[cfg_attr(feature = "wasm", wasm_bindgen)]
+#[derive(Debug, Clone, PartialEq, Default)]
+pub struct TextWithCursors {
+    text: String, // wasm-pack doesn't support generics so we can't use Cow here
+    cursors: Vec<CursorPosition>,
+}
+
+#[cfg_attr(feature = "wasm", wasm_bindgen)]
+impl TextWithCursors {
+    #[cfg_attr(feature = "wasm", wasm_bindgen(constructor))]
+    #[must_use]
+    pub fn new(text: String, cursors: Vec<CursorPosition>) -> Self {
+        let length = text.chars().count();
+        for cursor in &cursors {
+            debug_assert!(
+                cursor.char_index <= length,
+                // cursor.char_index == length means that the cursor is at the end
+                "Cursor positions must be contained within the text or just after the end"
+            );
+        }
+
+        Self { text, cursors }
+    }
+
+    #[must_use]
+    pub fn text(&self) -> String { self.text.to_string() }
+
+    #[must_use]
+    pub fn cursors(&self) -> Vec<CursorPosition> { self.cursors.clone() }
+
+    #[must_use]
+    pub fn new_owned(text: String, cursors: Vec<CursorPosition>) -> Self { Self { text, cursors } }
+}
+
+impl<'a> From<&'a str> for TextWithCursors {
+    fn from(text: &'a str) -> Self {
+        Self {
+            text: text.into(),
+            cursors: Vec::new(),
+        }
+    }
+}

src/types/text_with_history.rs

@@ -5,7 +5,7 @@ use wasm_bindgen::prelude::*;
 
 use crate::types::history::History;
 
-/// Wrapper type to expose `(History, String)` to JS.
+/// Wrapper type for `(History, String)`
 #[cfg_attr(feature = "wasm", wasm_bindgen)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 #[derive(Debug, Clone, PartialEq)]
@@ -16,6 +16,7 @@ pub struct TextWithHistory {
 
 #[cfg_attr(feature = "wasm", wasm_bindgen)]
 impl TextWithHistory {
+    #[must_use]
     pub fn new(history: History, text: String) -> Self { TextWithHistory { history, text } }
 
     #[must_use]