on_progress takes u64.

src/engine.rs

@@ -3,7 +3,9 @@
 use crate::ast::{Expr, FnCallExpr, Ident, IdentX, ReturnType, Stmt};
 use crate::dynamic::{map_std_type_name, AccessMode, Union, Variant};
 use crate::fn_call::run_builtin_op_assignment;
-use crate::fn_native::{CallableFunction, Callback, IteratorFn, OnVarCallback};
+use crate::fn_native::{
+    CallableFunction, IteratorFn, OnPrintCallback, OnProgressCallback, OnVarCallback,
+};
 use crate::module::NamespaceRef;
 use crate::optimize::OptimizationLevel;
 use crate::packages::{Package, PackagesCollection, StandardPackage};
@@ -622,11 +624,11 @@ pub struct Engine {
     pub(crate) resolve_var: Option<OnVarCallback>,
 
     /// Callback closure for implementing the `print` command.
-    pub(crate) print: Callback<str, ()>,
+    pub(crate) print: OnPrintCallback,
     /// Callback closure for implementing the `debug` command.
-    pub(crate) debug: Callback<str, ()>,
+    pub(crate) debug: OnPrintCallback,
     /// Callback closure for progress reporting.
-    pub(crate) progress: Option<Callback<u64, Option<Dynamic>>>,
+    pub(crate) progress: Option<OnProgressCallback>,
 
     /// Optimize the AST after compilation.
     pub(crate) optimization_level: OptimizationLevel,
@@ -2542,7 +2544,7 @@ impl Engine {
 
         // Report progress - only in steps
         if let Some(progress) = &self.progress {
-            if let Some(token) = progress(&state.operations) {
+            if let Some(token) = progress(state.operations) {
                 // Terminate script if progress returns a termination token
                 return EvalAltResult::ErrorTerminated(token, Position::NONE).into();
             }

src/engine_api.rs

@@ -1726,7 +1726,7 @@ impl Engine {
     ///
     /// let mut engine = Engine::new();
     ///
-    /// engine.on_progress(move |&ops| {
+    /// engine.on_progress(move |ops| {
     ///     if ops > 10000 {
     ///         Some("Over 10,000 operations!".into())
     ///     } else if ops % 800 == 0 {
@@ -1748,7 +1748,7 @@ impl Engine {
     #[inline(always)]
     pub fn on_progress(
         &mut self,
-        callback: impl Fn(&u64) -> Option<Dynamic> + SendSync + 'static,
+        callback: impl Fn(u64) -> Option<Dynamic> + SendSync + 'static,
     ) -> &mut Self {
         self.progress = Some(Box::new(callback));
         self

src/fn_native.rs

@@ -343,18 +343,25 @@ pub type FnPlugin = dyn PluginFunction;
 #[cfg(feature = "sync")]
 pub type FnPlugin = dyn PluginFunction + Send + Sync;
 
-/// A standard callback function.
+/// A standard callback function for progress reporting.
 #[cfg(not(feature = "sync"))]
-pub type Callback<T, R> = Box<dyn Fn(&T) -> R + 'static>;
-/// A standard callback function.
+pub type OnProgressCallback = Box<dyn Fn(u64) -> Option<Dynamic> + 'static>;
+/// A standard callback function for progress reporting.
 #[cfg(feature = "sync")]
-pub type Callback<T, R> = Box<dyn Fn(&T) -> R + Send + Sync + 'static>;
+pub type OnProgressCallback = Box<dyn Fn(u64) -> Option<Dynamic> + Send + Sync + 'static>;
 
-/// A standard callback function.
+/// A standard callback function for printing.
+#[cfg(not(feature = "sync"))]
+pub type OnPrintCallback = Box<dyn Fn(&str) + 'static>;
+/// A standard callback function for printing.
+#[cfg(feature = "sync")]
+pub type OnPrintCallback<T, R> = Box<dyn Fn(&str) + Send + Sync + 'static>;
+
+/// A standard callback function for variable access.
 #[cfg(not(feature = "sync"))]
 pub type OnVarCallback =
     Box<dyn Fn(&str, usize, &EvalContext) -> Result<Option<Dynamic>, Box<EvalAltResult>> + 'static>;
-/// A standard callback function.
+/// A standard callback function for variable access.
 #[cfg(feature = "sync")]
 pub type OnVarCallback = Box<
     dyn Fn(&str, usize, &EvalContext) -> Result<Option<Dynamic>, Box<EvalAltResult>>