Replace use of unstable Option::flatten() with and_then()

src/commands/save.rs

@@ -59,7 +59,7 @@ fn save(
             // If there is no filename, check the metadata for the origin filename
             if input.len() > 0 {
                 let origin = input[0].origin();
-                match origin.map(|x| source_map.get(&x)).flatten() {
+                match origin.and_then(|x| source_map.get(&x)) {
                     Some(path) => match path {
                         SpanSource::File(file) => {
                             full_path.push(Path::new(file));

src/commands/tags.rs

@@ -38,7 +38,7 @@ fn tags(args: CommandArgs, _registry: &CommandRegistry) -> Result<OutputStream,
                 dict.insert("end", Value::int(span.end as i64));
                 tags.insert_tagged("span", dict.into_tagged_value());
 
-                match origin.map(|x| source_map.get(&x)).flatten() {
+                match origin.and_then(|x| source_map.get(&x)) {
                     Some(SpanSource::File(source)) => {
                         tags.insert("origin", Value::string(source));
                     }

src/lib.rs

@@ -3,7 +3,6 @@
 #![feature(generators)]
 #![feature(try_trait)]
 #![feature(bind_by_move_pattern_guards)]
-#![feature(option_flattening)]
 #![feature(specialization)]
 #![feature(proc_macro_hygiene)]
 

src/plugins/binaryview.rs

@@ -1,4 +1,3 @@
-#![feature(option_flattening)]
 use crossterm::{cursor, terminal, Attribute, RawScreen};
 use indexmap::IndexMap;
 use nu::{
@@ -32,7 +31,7 @@ impl Plugin for BinaryView {
             let value_origin = v.origin();
             match v.item {
                 Value::Binary(b) => {
-                    let source = value_origin.map(|x| call_info.source_map.get(&x)).flatten();
+                    let source = value_origin.and_then(|x| call_info.source_map.get(&x));
                     let _ = view_binary(&b, source, call_info.args.has("lores"));
                 }
                 _ => {}

src/plugins/textview.rs

@@ -1,5 +1,3 @@
-#![feature(option_flattening)]
-
 use crossterm::{cursor, terminal, RawScreen};
 use crossterm::{InputEvent, KeyEvent};
 use indexmap::IndexMap;
@@ -217,7 +215,7 @@ fn view_text_value(value: &Tagged<Value>, source_map: &SourceMap) {
     let value_origin = value.origin();
     match value.item {
         Value::Primitive(Primitive::String(ref s)) => {
-            let source = value_origin.map(|x| source_map.get(&x)).flatten();
+            let source = value_origin.and_then(|x| source_map.get(&x));
 
             if let Some(source) = source {
                 let extension: Option<String> = match source {