Style: move some Option if/else to method chains (#12285)

- **Use `bool::then` where it simplifies readability**
- **More debatable uses of `bool::then`**
- **Use `Option::filter` in `find_active_overlay`**

crates/nu-protocol/src/debugger/profiler.rs

@@ -68,16 +68,8 @@ impl Profiler {
             duration_sec: 0.0,
             depth: 0,
             element_span: span,
-            element_output: if collect_values {
+            element_output: collect_values.then(|| Value::nothing(span)),
-                Some(Value::nothing(span))
+            expr: collect_exprs.then(|| "call".to_string()),
-            } else {
-                None
-            },
-            expr: if collect_exprs {
-                Some("call".to_string())
-            } else {
-                None
-            },
             children: vec![],
         };
 
@@ -141,11 +133,9 @@ impl Debugger for Profiler {
             return;
         };
 
-        let expr_opt = if self.collect_exprs {
+        let expr_opt = self
-            Some(expr_to_string(engine_state, &element.expr.expr))
+            .collect_exprs
-        } else {
+            .then(|| expr_to_string(engine_state, &element.expr.expr));
-            None
-        };
 
         let new_id = ElementId(self.elements.len());
 
@@ -175,8 +165,7 @@ impl Debugger for Profiler {
 
         let element_span = element.expr.span;
 
-        let out_opt = if self.collect_values {
+        let out_opt = self.collect_values.then(|| match result {
-            Some(match result {
             Ok((pipeline_data, _not_sure_what_this_is)) => match pipeline_data {
                 PipelineData::Value(val, ..) => val.clone(),
                 PipelineData::ListStream(..) => Value::string("list stream", element_span),
@@ -186,10 +175,7 @@ impl Debugger for Profiler {
                 _ => Value::nothing(element_span),
             },
             Err(e) => Value::error(e.clone(), element_span),
-            })
+        });
-        } else {
-            None
-        };
 
         let Some(last_element) = self.last_element_mut() else {
             eprintln!("Profiler Error: Missing last element.");

crates/nu-protocol/src/engine/engine_state.rs

@@ -790,11 +790,7 @@ impl EngineState {
 
     /// Returns the configuration settings for command history or `None` if history is disabled
     pub fn history_config(&self) -> Option<HistoryConfig> {
-        if self.history_enabled {
+        self.history_enabled.then(|| self.config.history)
-            Some(self.config.history)
-        } else {
-            None
-        }
     }
 
     pub fn get_var(&self, var_id: VarId) -> &Variable {

crates/nu-protocol/src/engine/overlay.rs

@@ -168,13 +168,7 @@ impl ScopeFrame {
         self.overlays
             .iter()
             .position(|(n, _)| n == name)
-            .and_then(|id| {
+            .filter(|id| self.active_overlays.contains(id))
-                if self.active_overlays.contains(&id) {
-                    Some(id)
-                } else {
-                    None
-                }
-            })
     }
 }