[Rust] Add docs for what the boolean return value does for some specific "progress" like callbacks

Still need to add more, consider changing the boolean to an enum that describes it better, so we do not need to copy paste docs around.

Author: emesare

rust/src/binary_view.rs

@@ -235,11 +235,15 @@ pub trait BinaryViewExt: BinaryViewBase {
     }
 
     /// Search the view using the query options.
+    ///
+    /// In the `on_match` callback return `false` to stop searching.
     fn search<C: FnMut(u64, &DataBuffer) -> bool>(&self, query: &SearchQuery, on_match: C) -> bool {
         self.search_with_progress(query, on_match, NoProgressCallback)
     }
 
     /// Search the view using the query options.
+    /// 
+    /// In the `on_match` callback return `false` to stop searching.
     fn search_with_progress<P: ProgressCallback, C: FnMut(u64, &DataBuffer) -> bool>(
         &self,
         query: &SearchQuery,

rust/src/progress.rs

@@ -2,6 +2,10 @@ use std::ffi::c_void;
 
 pub trait ProgressCallback: Sized {
     type SplitProgressType: SplitProgressBuilder;
+    
+    /// Caller function will call this to report progress.
+    /// 
+    /// Return `false` to tell the caller to stop.
     fn progress(&mut self, progress: usize, total: usize) -> bool;
 
     unsafe extern "C" fn cb_progress_callback(