mentat/edn/src/utils.rs

31 lines
1.2 KiB
Rust

// Copyright 2016 Mozilla
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may not use
// this file except in compliance with the License. You may obtain a copy of the
// License at http://www.apache.org/licenses/LICENSE-2.0
// Unless required by applicable law or agreed to in writing, software distributed
// under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
// CONDITIONS OF ANY KIND, either express or implied. See the License for the
// specific language governing permissions and limitations under the License.
#![allow(dead_code)]
use crate::types::Value;
/// Merge the EDN `Value::Map` instance `right` into `left`. Returns `None` if either `left` or
/// `right` is not a `Value::Map`.
///
/// Keys present in `right` overwrite keys present in `left`. See also
/// https://clojuredocs.org/clojure.core/merge.
///
/// TODO: implement `merge` for [Value], following the `concat`/`SliceConcatExt` pattern.
pub fn merge(left: &Value, right: &Value) -> Option<Value> {
match (left, right) {
(&Value::Map(ref l), &Value::Map(ref r)) => {
let mut result = l.clone();
result.extend(r.clone().into_iter());
Some(Value::Map(result))
}
_ => None,
}
}