Merge nucleic/sleek-thistle-egret-fyej into dev

brush-interactive/src/input_backend.rs

@@ -0,0 +1,51 @@
+use crate::ShellError;
+
+/// Represents an input backend for reading lines of input.
+pub trait InputBackend: Send {
+    /// Reads a line of input, using the given prompt.
+    ///
+    /// # Arguments
+    ///
+    /// * `shell` - The shell instance for which input is being read.
+    /// * `prompt` - The prompt to display to the user.
+    fn read_line(
+        &mut self,
+        shell: &crate::ShellRef<impl brush_core::ShellExtensions>,
+        prompt: InteractivePrompt,
+    ) -> Result<ReadResult, ShellError>;
+
+    /// Returns the current contents of the read buffer and the current cursor
+    /// position within the buffer; None is returned if the read buffer is
+    /// empty or cannot be read by this implementation.
+    fn get_read_buffer(&self) -> Option<(String, usize)> {
+        None
+    }
+
+    /// Updates the read buffer with the given string and cursor. Considered a
+    /// no-op if the implementation does not support updating read buffers.
+    fn set_read_buffer(&mut self, _buffer: String, _cursor: usize) {
+        // No-op by default.
+    }
+}
+
+/// Result of a read operation.
+pub enum ReadResult {
+    /// The user entered a line of input.
+    Input(String),
+    /// A bound key sequence yielded a registered command.
+    BoundCommand(String),
+    /// End of input was reached.
+    Eof,
+    /// The user interrupted the input operation.
+    Interrupted,
+}
+
+/// Represents an interactive prompt.
+pub struct InteractivePrompt {
+    /// Prompt to display.
+    pub prompt: String,
+    /// Alternate-side prompt (typically right) to display.
+    pub alt_side_prompt: String,
+    /// Prompt to display on a continuation line of input.
+    pub continuation_prompt: String,
+}