Clippy fix for Rust 1.63 (#6299)

Take more sensitive lints into account

Somewhat ugly in some cases is the replacement of `.get(0)` with
`.first()`

crates/nu-command/src/conversions/into/datetime.rs

@@ -311,7 +311,7 @@ fn action(
                 Some(dt) => match DateTime::parse_from_str(val, &dt.0) {
                     Ok(d) => Value::Date { val: d, span: head },
                     Err(reason) => {
-                        return Value::Error {
+                        Value::Error {
                             error: ShellError::CantConvert(
                                 format!("could not parse as datetime using format '{}'", dt.0),
                                 reason.to_string(),

crates/nu-command/src/database/commands/alias.rs

@@ -145,15 +145,13 @@ fn alias_db(
                     Vec::new(),
                 )),
             },
-            s => {
-                return Err(ShellError::GenericError(
-                    "Connection doesn't define a query".into(),
-                    format!("Expected a connection with query. Got {}", s),
-                    Some(call.head),
-                    None,
-                    Vec::new(),
-                ))
-            }
+            s => Err(ShellError::GenericError(
+                "Connection doesn't define a query".into(),
+                format!("Expected a connection with query. Got {}", s),
+                Some(call.head),
+                None,
+                Vec::new(),
+            )),
         },
     }
 }

crates/nu-command/src/database/values/definitions/db.rs

@@ -3,7 +3,7 @@ use super::db_table::DbTable;
 // Thank you gobang
 // https://github.com/TaKO8Ki/gobang/blob/main/database-tree/src/lib.rs
 
-#[derive(Clone, PartialEq, Debug)]
+#[derive(Clone, PartialEq, Eq, Debug)]
 pub struct Db {
     pub name: String,
     pub tables: Vec<DbTable>,

crates/nu-command/src/database/values/definitions/db_schema.rs

@@ -1,6 +1,6 @@
 use super::db_table::DbTable;
 
-#[derive(Clone, PartialEq, Debug)]
+#[derive(Clone, PartialEq, Eq, Debug)]
 pub struct DbSchema {
     pub name: String,
     pub tables: Vec<DbTable>,

crates/nu-command/src/database/values/definitions/db_table.rs

@@ -1,4 +1,4 @@
-#[derive(Debug, Clone, PartialEq)]
+#[derive(Debug, Clone, Eq, PartialEq)]
 pub struct DbTable {
     pub name: String,
     pub create_time: Option<chrono::DateTime<chrono::Utc>>,

crates/nu-command/src/database/values/definitions/mod.rs

@@ -11,7 +11,7 @@ pub mod db_row;
 pub mod db_schema;
 pub mod db_table;
 
-#[derive(Clone, Debug, Serialize, Deserialize, PartialEq)]
+#[derive(Clone, Debug, Serialize, Deserialize, Eq, PartialEq)]
 pub enum ConnectionDb {
     Path(PathBuf),
 }

crates/nu-command/src/dataframe/values/nu_dataframe/mod.rs

@@ -446,7 +446,7 @@ impl NuDataFrame {
         // sorting dataframe by the first column
         let column_names = self.as_ref().get_column_names();
         let first_col = column_names
-            .get(0)
+            .first()
             .expect("already checked that dataframe is different than 0");
 
         // if unable to sort, then unable to compare

crates/nu-command/src/filters/drop/nth.rs

@@ -206,7 +206,7 @@ impl Iterator for DropNthIterator {
 
     fn next(&mut self) -> Option<Self::Item> {
         loop {
-            if let Some(row) = self.rows.get(0) {
+            if let Some(row) = self.rows.first() {
                 if self.current == *row {
                     self.rows.remove(0);
                     self.current += 1;

crates/nu-command/src/filters/select.rs

@@ -207,7 +207,7 @@ impl Iterator for NthIterator {
     fn next(&mut self) -> Option<Self::Item> {
         loop {
             if !self.skip {
-                if let Some(row) = self.rows.get(0) {
+                if let Some(row) = self.rows.first() {
                     if self.current == *row {
                         self.rows.remove(0);
                         self.current += 1;
@@ -220,7 +220,7 @@ impl Iterator for NthIterator {
                 } else {
                     return None;
                 }
-            } else if let Some(row) = self.rows.get(0) {
+            } else if let Some(row) = self.rows.first() {
                 if self.current == *row {
                     self.rows.remove(0);
                     self.current += 1;

crates/nu-command/src/filters/sort.rs

@@ -153,7 +153,7 @@ impl Command for Sort {
                 }
 
                 let iter = vec.into_iter();
-                match &*metadata {
+                match metadata {
                     Some(m) => Ok(iter
                         .into_pipeline_data_with_metadata(m.clone(), engine_state.ctrlc.clone())),
                     None => Ok(iter.into_pipeline_data(engine_state.ctrlc.clone())),

crates/nu-command/src/filters/sort_by.rs

@@ -158,7 +158,7 @@ impl Command for SortBy {
         }
 
         let iter = vec.into_iter();
-        match &*metadata {
+        match metadata {
             Some(m) => {
                 Ok(iter.into_pipeline_data_with_metadata(m.clone(), engine_state.ctrlc.clone()))
             }

crates/nu-command/src/strings/str_/index_of.rs

@@ -217,7 +217,7 @@ fn process_range(
         Value::String { val: s, .. } => {
             let indexes: Vec<&str> = s.split(',').collect();
 
-            let start_index = indexes.get(0).unwrap_or(&&min_index_str[..]).to_string();
+            let start_index = indexes.first().unwrap_or(&&min_index_str[..]).to_string();
 
             let end_index = indexes.get(1).unwrap_or(&&max_index_str[..]).to_string();
 

crates/nu-command/src/strings/str_/substring.rs

@@ -247,7 +247,7 @@ fn process_arguments(options: &Arguments, head: Span) -> Result<(isize, isize),
             let idx: Vec<&str> = val.split(',').collect();
 
             let start = idx
-                .get(0)
+                .first()
                 .ok_or_else(|| {
                     ShellError::UnsupportedInput("could not perform substring".to_string(), head)
                 })?