Replace fun input with ownership

README.md

@@ -92,7 +92,7 @@ let result = selector_mut
             0
         };
 
-        json!(age)
+        Some(json!(age))
     }).unwrap()
     .take().unwrap();
 
@@ -353,7 +353,7 @@ let ret = jsonpath::replace_with(json_obj, "$..[?(@.age == 20)].age", &mut |v| {
         0
     };
 
-    json!(age)
+    Some(json!(age))
 }).unwrap();
 
 assert_eq!(ret, json!({

src/lib.rs

@@ -443,7 +443,7 @@ pub fn delete(value: Value, path: &str) -> Result<Value, JsonPathError> {
 ///         0
 ///     };
 ///
-///     json!(age)
+///     Some(json!(age))
 /// }).unwrap();
 ///
 /// assert_eq!(ret, json!({
@@ -460,7 +460,7 @@ pub fn delete(value: Value, path: &str) -> Result<Value, JsonPathError> {
 /// ```
 pub fn replace_with<F>(value: Value, path: &str, fun: &mut F) -> Result<Value, JsonPathError>
 where
-    F: FnMut(Value) -> Value,
+    F: FnMut(Value) -> Option<Value>,
 {
     let mut selector = SelectorMut::default();
     let value = selector.str_path(path)?.value(value).replace_with(fun)?;

src/select/mod.rs

@@ -1027,7 +1027,7 @@ pub struct SelectorMut {
     value: Option<Value>,
 }
 
-fn replace_value<F: FnMut(Value) -> Value>(mut tokens: Vec<String>, value: &mut Value, fun: &mut F) {
+fn replace_value<F: FnMut(Value) -> Option<Value>>(mut tokens: Vec<String>, value: &mut Value, fun: &mut F) {
     let mut target = value;
 
     let last_index = tokens.len() - 1;
@@ -1039,7 +1039,11 @@ fn replace_value<F: FnMut(Value) -> Value>(mut tokens: Vec<String>, value: &mut
                 if is_last {
                     if let Entry::Occupied(mut e) = map.entry(token) {
                         let v = e.insert(Value::Null);
-                        e.insert(fun(v));
+                        if let Some(res) = fun(v) {
+                            e.insert(res);
+                        } else {
+                            e.remove();
+                        }
                     }
                     return;
                 }
@@ -1049,7 +1053,11 @@ fn replace_value<F: FnMut(Value) -> Value>(mut tokens: Vec<String>, value: &mut
                 if let Ok(x) = token.parse::<usize>() {
                     if is_last {
                         let v = std::mem::replace(&mut vec[x], Value::Null);
-                        vec[x] = fun(v);
+                        if let Some(res) = fun(v) {
+                            vec[x] = res;
+                        } else {
+                            vec.remove(x);
+                        }
                         return;
                     }
                     vec.get_mut(x)
@@ -1155,7 +1163,11 @@ impl SelectorMut {
     }
 
     pub fn delete(&mut self) -> Result<&mut Self, JsonPathError> {
-        self.replace_with(&mut |_| Value::Null)
+        self.replace_with(&mut |_| Some(Value::Null))
+    }
+
+    pub fn remove(&mut self) -> Result<&mut Self, JsonPathError> {
+        self.replace_with(&mut |_| None)
     }
 
     fn select(&self) -> Result<Vec<&Value>, JsonPathError> {
@@ -1173,7 +1185,7 @@ impl SelectorMut {
         }
     }
 
-    pub fn replace_with<F: FnMut(Value) -> Value>(
+    pub fn replace_with<F: FnMut(Value) -> Option<Value>>(
         &mut self,
         fun: &mut F,
     ) -> Result<&mut Self, JsonPathError> {

tests/readme.rs

@@ -224,7 +224,7 @@ fn readme_selector_mut() {
                 0
             };
 
-            json!(age)
+            Some(json!(age))
         })
         .unwrap()
         .take()
@@ -522,7 +522,7 @@ fn readme_replace_with() {
             0
         };
 
-        json!(age)
+        Some(json!(age))
     })
     .unwrap();
 

tests/selector.rs

@@ -23,7 +23,7 @@ fn selector_mut() {
             if let Value::Number(n) = v {
                 nums.push(n.as_f64().unwrap());
             }
-            Value::String("a".to_string())
+            Some(Value::String("a".to_string()))
         })
         .unwrap()
         .take()
@@ -96,3 +96,37 @@ fn selector_delete() {
         ]
     );
 }
+
+#[test]
+fn selector_remove() {
+    setup();
+
+    let mut selector_mut = SelectorMut::default();
+
+    let result = selector_mut
+        .str_path(r#"$.store..price[?(@>13)]"#)
+        .unwrap()
+        .value(read_json("./benchmark/example.json"))
+        .remove()
+        .unwrap()
+        .take()
+        .unwrap();
+
+    let mut selector = Selector::default();
+    let result = selector
+        .str_path(r#"$.store..price"#)
+        .unwrap()
+        .value(&result)
+        .select()
+        .unwrap();
+
+    assert_eq!(
+        result,
+        vec![
+            &json!(8.95),
+            &json!(12.99),
+            &json!(8.99)
+        ]
+    );
+}
+

wasm/src/lib.rs

@@ -56,24 +56,24 @@ where
     }
 }
 
-fn replace_fun(v: Value, fun: &js_sys::Function) -> Value {
+fn replace_fun(v: Value, fun: &js_sys::Function) -> Option<Value> {
     match JsValue::from_serde(&v) {
         Ok(js_v) => match fun.call1(&JsValue::NULL, &js_v) {
             Ok(result) => match into_serde_json(&result) {
-                Ok(json) => json,
+                Ok(json) => Some(json),
                 Err(e) => {
                     console_error!("replace_with - closure returned a invalid JSON: {:?}", e);
-                    Value::Null
+                    Some(Value::Null)
                 }
             },
             Err(e) => {
                 console_error!("replace_with - fail to call closure: {:?}", e);
-                Value::Null
+                Some(Value::Null)
             }
         },
         Err(e) => {
             console_error!("replace_with - invalid JSON object: {:?}", e);
-            Value::Null
+            Some(Value::Null)
         }
     }
 }