Add cursor types

backend/reconcile/src/cursor.rs

@@ -0,0 +1,45 @@
+use std::borrow::Cow;
+
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+
+// CursorPosition is a wrapper around usize to represent the position of an
+// identifiable cursor in a text document based on the character index.
+#[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 = "serde", derive(Serialize, Deserialize))]
+#[derive(Debug, Clone, PartialEq, Default)]
+pub struct TextWithCursors<'a> {
+    pub text: Cow<'a, str>,
+    pub cursors: Vec<CursorPosition>,
+}
+
+impl<'a> TextWithCursors<'a> {
+    pub fn new(text: &'a str, cursors: Vec<CursorPosition>) -> Self {
+        Self {
+            text: text.into(),
+            cursors,
+        }
+    }
+
+    pub fn new_owned(text: String, cursors: Vec<CursorPosition>) -> Self {
+        Self {
+            text: text.into(),
+            cursors,
+        }
+    }
+}
+
+impl<'a> From<&'a str> for TextWithCursors<'a> {
+    fn from(text: &'a str) -> Self {
+        Self {
+            text: text.into(),
+            cursors: Vec::new(),
+        }
+    }
+}

backend/sync_lib/src/cursor.rs

@@ -0,0 +1,71 @@
+use reconcile::{CursorPosition, TextWithCursors};
+use wasm_bindgen::prelude::*;
+
+/// Wrapper type to expose `TextWithCursors` to JS.
+#[wasm_bindgen]
+#[derive(Debug, Clone, PartialEq)]
+pub struct OwnedTextWithCursors {
+    text: String,
+    cursors: Vec<OwnedCursorPosition>,
+}
+
+impl OwnedTextWithCursors {
+    pub fn new(text: impl Into<String>, cursors: Vec<OwnedCursorPosition>) -> Self {
+        Self {
+            text: text.into(),
+            cursors,
+        }
+    }
+}
+
+impl From<OwnedTextWithCursors> for TextWithCursors<'_> {
+    fn from(owned: OwnedTextWithCursors) -> Self {
+        TextWithCursors::new_owned(
+            owned.text.to_string(),
+            owned
+                .cursors
+                .into_iter()
+                .map(|cursor| cursor.into())
+                .collect(),
+        )
+    }
+}
+
+impl From<TextWithCursors<'_>> for OwnedTextWithCursors {
+    fn from(text_with_cursors: TextWithCursors<'_>) -> Self {
+        OwnedTextWithCursors {
+            text: text_with_cursors.text.into_owned(),
+            cursors: text_with_cursors
+                .cursors
+                .into_iter()
+                .map(|cursor| cursor.into())
+                .collect(),
+        }
+    }
+}
+
+/// Wrapper type to expose `CursorPosition` to JS.
+#[wasm_bindgen]
+#[derive(Debug, Clone, PartialEq)]
+pub struct OwnedCursorPosition {
+    pub id: usize,
+    pub char_index: usize,
+}
+
+impl From<OwnedCursorPosition> for CursorPosition {
+    fn from(owned: OwnedCursorPosition) -> Self {
+        CursorPosition {
+            id: owned.id,
+            char_index: owned.char_index,
+        }
+    }
+}
+
+impl From<CursorPosition> for OwnedCursorPosition {
+    fn from(cursor: CursorPosition) -> Self {
+        OwnedCursorPosition {
+            id: cursor.id,
+            char_index: cursor.char_index,
+        }
+    }
+}