[INFO] updating cached repository bwhetherington/rust-lisp
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/bwhetherington/rust-lisp
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/bwhetherington/rust-lisp" "work/ex/clippy-test-run/sources/stable/gh/bwhetherington/rust-lisp"`
[INFO] [stderr] Cloning into 'work/ex/clippy-test-run/sources/stable/gh/bwhetherington/rust-lisp'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/bwhetherington/rust-lisp" "work/ex/clippy-test-run/sources/stable+rustflags=-Dclippy%3A%3Ainto_iter_on_array/gh/bwhetherington/rust-lisp"`
[INFO] [stderr] Cloning into 'work/ex/clippy-test-run/sources/stable+rustflags=-Dclippy%3A%3Ainto_iter_on_array/gh/bwhetherington/rust-lisp'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 7807a8d7f06aed76468a3df13fd60274eb297d67
[INFO] sha for GitHub repo bwhetherington/rust-lisp: 7807a8d7f06aed76468a3df13fd60274eb297d67
[INFO] validating manifest of bwhetherington/rust-lisp on toolchain stable
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+stable" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of bwhetherington/rust-lisp on toolchain stable+rustflags=-Dclippy::into_iter_on_array
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+stable" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing bwhetherington/rust-lisp
[INFO] finished frobbing bwhetherington/rust-lisp
[INFO] frobbed toml for bwhetherington/rust-lisp written to work/ex/clippy-test-run/sources/stable/gh/bwhetherington/rust-lisp/Cargo.toml
[INFO] started frobbing bwhetherington/rust-lisp
[INFO] finished frobbing bwhetherington/rust-lisp
[INFO] frobbed toml for bwhetherington/rust-lisp written to work/ex/clippy-test-run/sources/stable+rustflags=-Dclippy%3A%3Ainto_iter_on_array/gh/bwhetherington/rust-lisp/Cargo.toml
[INFO] crate bwhetherington/rust-lisp has a lockfile. skipping
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+stable" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+stable" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] linting bwhetherington/rust-lisp against stable+rustflags=-Dclippy::into_iter_on_array for clippy-test-run
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/clippy-test-run/worker-1/stable+rustflags=-Dclippy%3A%3Ainto_iter_on_array:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/clippy-test-run/sources/stable+rustflags=-Dclippy%3A%3Ainto_iter_on_array/gh/bwhetherington/rust-lisp:/opt/crater/workdir:ro,Z" "-v" "/mnt/big/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/big/crater/work/local/rustup-home:/opt/crater/rustup-home:ro,Z" "-e" "USER_ID=1000" "-e" "SOURCE_DIR=/opt/crater/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/crater/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid -Dclippy::into_iter_on_array" "-e" "CARGO_HOME=/opt/crater/cargo-home" "-e" "RUSTUP_HOME=/opt/crater/rustup-home" "-w" "/opt/crater/workdir" "-m" "1536M" "--network" "none" "rustops/crates-build-env" "/opt/crater/cargo-home/bin/cargo" "+stable" "clippy" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] a8f83a5815c0dcd8316fa95144c802931446b08de0b61df82118d4f07b2d49db
[INFO] running `"docker" "start" "-a" "a8f83a5815c0dcd8316fa95144c802931446b08de0b61df82118d4f07b2d49db"`
[INFO] [stderr]     Checking rust-lisp v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: unused import: `std::collections::HashMap`
[INFO] [stderr]  --> src/interpreter.rs:1:5
[INFO] [stderr]   |
[INFO] [stderr] 1 | use std::collections::HashMap;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(unused_imports)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `parser::Parser`
[INFO] [stderr]  --> src/intrinsics.rs:2:5
[INFO] [stderr]   |
[INFO] [stderr] 2 | use parser::Parser;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: Constants have by default a `'static` lifetime
[INFO] [stderr]  --> src/intrinsics.rs:8:25
[INFO] [stderr]   |
[INFO] [stderr] 8 | const RESERVED_WORDS: [&'static str; 6] = [
[INFO] [stderr]   |                        -^^^^^^^---- help: consider removing `'static`: `&str`
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(clippy::const_static_lifetime)] on by default
[INFO] [stderr]   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#const_static_lifetime
[INFO] [stderr] 
[INFO] [stderr] warning: Constants have by default a `'static` lifetime
[INFO] [stderr]   --> src/intrinsics.rs:17:28
[INFO] [stderr]    |
[INFO] [stderr] 17 | const FIELD_NAMES_FORMAT: &'static str = "{}-field-names";
[INFO] [stderr]    |                           -^^^^^^^---- help: consider removing `'static`: `&str`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#const_static_lifetime
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `std::fs`
[INFO] [stderr]  --> src/utils.rs:2:5
[INFO] [stderr]   |
[INFO] [stderr] 2 | use std::fs;
[INFO] [stderr]   |     ^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `environment::Environment`
[INFO] [stderr]  --> src/values.rs:5:5
[INFO] [stderr]   |
[INFO] [stderr] 5 | use environment::Environment;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: Constants have by default a `'static` lifetime
[INFO] [stderr]   --> src/main.rs:26:14
[INFO] [stderr]    |
[INFO] [stderr] 26 | const NAME: &'static str = env!("CARGO_PKG_NAME");
[INFO] [stderr]    |             -^^^^^^^---- help: consider removing `'static`: `&str`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#const_static_lifetime
[INFO] [stderr] 
[INFO] [stderr] warning: Constants have by default a `'static` lifetime
[INFO] [stderr]   --> src/main.rs:27:17
[INFO] [stderr]    |
[INFO] [stderr] 27 | const VERSION: &'static str = env!("CARGO_PKG_VERSION");
[INFO] [stderr]    |                -^^^^^^^---- help: consider removing `'static`: `&str`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#const_static_lifetime
[INFO] [stderr] 
[INFO] [stderr] warning: use of deprecated item 'std::env::home_dir': This function's behavior is unexpected and probably not what you want. Consider using the home_dir function from https://crates.io/crates/dirs instead.
[INFO] [stderr]  --> src/utils.rs:5:29
[INFO] [stderr]   |
[INFO] [stderr] 5 |     if let Some(home_dir) = env::home_dir() {
[INFO] [stderr]   |                             ^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(deprecated)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `std::collections::HashMap`
[INFO] [stderr]  --> src/interpreter.rs:1:5
[INFO] [stderr]   |
[INFO] [stderr] 1 | use std::collections::HashMap;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(unused_imports)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `parser::Parser`
[INFO] [stderr]  --> src/intrinsics.rs:2:5
[INFO] [stderr]   |
[INFO] [stderr] 2 | use parser::Parser;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: Constants have by default a `'static` lifetime
[INFO] [stderr]  --> src/intrinsics.rs:8:25
[INFO] [stderr]   |
[INFO] [stderr] 8 | const RESERVED_WORDS: [&'static str; 6] = [
[INFO] [stderr]   |                        -^^^^^^^---- help: consider removing `'static`: `&str`
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(clippy::const_static_lifetime)] on by default
[INFO] [stderr]   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#const_static_lifetime
[INFO] [stderr] 
[INFO] [stderr] warning: Constants have by default a `'static` lifetime
[INFO] [stderr]   --> src/intrinsics.rs:17:28
[INFO] [stderr]    |
[INFO] [stderr] 17 | const FIELD_NAMES_FORMAT: &'static str = "{}-field-names";
[INFO] [stderr]    |                           -^^^^^^^---- help: consider removing `'static`: `&str`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#const_static_lifetime
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `std::fs`
[INFO] [stderr]  --> src/utils.rs:2:5
[INFO] [stderr]   |
[INFO] [stderr] 2 | use std::fs;
[INFO] [stderr]   |     ^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `environment::Environment`
[INFO] [stderr]  --> src/values.rs:5:5
[INFO] [stderr]   |
[INFO] [stderr] 5 | use environment::Environment;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: Constants have by default a `'static` lifetime
[INFO] [stderr]   --> src/main.rs:26:14
[INFO] [stderr]    |
[INFO] [stderr] 26 | const NAME: &'static str = env!("CARGO_PKG_NAME");
[INFO] [stderr]    |             -^^^^^^^---- help: consider removing `'static`: `&str`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#const_static_lifetime
[INFO] [stderr] 
[INFO] [stderr] warning: Constants have by default a `'static` lifetime
[INFO] [stderr]   --> src/main.rs:27:17
[INFO] [stderr]    |
[INFO] [stderr] 27 | const VERSION: &'static str = env!("CARGO_PKG_VERSION");
[INFO] [stderr]    |                -^^^^^^^---- help: consider removing `'static`: `&str`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#const_static_lifetime
[INFO] [stderr] 
[INFO] [stderr] warning: use of deprecated item 'std::env::home_dir': This function's behavior is unexpected and probably not what you want. Consider using the home_dir function from https://crates.io/crates/dirs instead.
[INFO] [stderr]  --> src/utils.rs:5:29
[INFO] [stderr]   |
[INFO] [stderr] 5 |     if let Some(home_dir) = env::home_dir() {
[INFO] [stderr]   |                             ^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(deprecated)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `env`
[INFO] [stderr]    --> src/intrinsics.rs:174:20
[INFO] [stderr]     |
[INFO] [stderr] 174 |     pub fn _lambda(env: Env, exprs: Exprs) -> Output {
[INFO] [stderr]     |                    ^^^ help: consider using `_env` instead
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(unused_variables)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `num_values`
[INFO] [stderr]    --> src/intrinsics.rs:335:29
[INFO] [stderr]     |
[INFO] [stderr] 335 |                         let num_values = len - 1;
[INFO] [stderr]     |                             ^^^^^^^^^^ help: consider using `_num_values` instead
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `env`
[INFO] [stderr]    --> src/intrinsics.rs:174:20
[INFO] [stderr]     |
[INFO] [stderr] 174 |     pub fn _lambda(env: Env, exprs: Exprs) -> Output {
[INFO] [stderr]     |                    ^^^ help: consider using `_env` instead
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(unused_variables)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `num_values`
[INFO] [stderr]    --> src/intrinsics.rs:335:29
[INFO] [stderr]     |
[INFO] [stderr] 335 |                         let num_values = len - 1;
[INFO] [stderr]     |                             ^^^^^^^^^^ help: consider using `_num_values` instead
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `parse_from_str`
[INFO] [stderr]   --> src/parser.rs:18:5
[INFO] [stderr]    |
[INFO] [stderr] 18 |     pub fn parse_from_str(&mut self, s: &str) -> Parse {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(dead_code)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `peak_char`
[INFO] [stderr]    --> src/parser.rs:170:5
[INFO] [stderr]     |
[INFO] [stderr] 170 |     fn peak_char<R: Read>(&mut self, r: &mut BufReader<R>) -> Option<char> {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: constant item is never used: `FIELD_NAMES_FORMAT`
[INFO] [stderr]   --> src/intrinsics.rs:17:1
[INFO] [stderr]    |
[INFO] [stderr] 17 | const FIELD_NAMES_FORMAT: &'static str = "{}-field-names";
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `cur_scope`
[INFO] [stderr]   --> src/environment.rs:17:5
[INFO] [stderr]    |
[INFO] [stderr] 17 |     fn cur_scope(&self) -> &HashMap<String, Value> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: the loop variable `i` is only used to index `exps`.
[INFO] [stderr]   --> src/sexpr.rs:38:30
[INFO] [stderr]    |
[INFO] [stderr] 38 |                     for i in 0..len - 1 {
[INFO] [stderr]    |                              ^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::needless_range_loop)] on by default
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_range_loop
[INFO] [stderr] help: consider using an iterator
[INFO] [stderr]    |
[INFO] [stderr] 38 |                     for <item> in exps.iter().take(len - 1) {
[INFO] [stderr]    |                         ^^^^^^    ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: useless use of `format!`
[INFO] [stderr]    --> src/intrinsics.rs:141:29
[INFO] [stderr]     |
[INFO] [stderr] 141 |                         Err(format!("Cannot redefine empty list."))
[INFO] [stderr]     |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using .to_string(): `"Cannot redefine empty list.".to_string()`
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(clippy::useless_format)] on by default
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_format
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/intrinsics.rs:185:21
[INFO] [stderr]     |
[INFO] [stderr] 185 | /                     match param {
[INFO] [stderr] 186 | |                         &SExpr::Ident(ref s) => names.push(s.to_string()),
[INFO] [stderr] 187 | |                         _ => return Err(not_an_identifier(param))
[INFO] [stderr] 188 | |                     }
[INFO] [stderr]     | |_____________________^
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(clippy::match_ref_pats)] on by default
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 185 |                     match *param {
[INFO] [stderr] 186 |                         SExpr::Ident(ref s) => names.push(s.to_string()),
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: useless use of `format!`
[INFO] [stderr]    --> src/intrinsics.rs:366:37
[INFO] [stderr]     |
[INFO] [stderr] 366 |                                 Err(format!("hi"))
[INFO] [stderr]     |                                     ^^^^^^^^^^^^^ help: consider using .to_string(): `"hi".to_string()`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_format
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/intrinsics.rs:405:17
[INFO] [stderr]     |
[INFO] [stderr] 405 | /                 match code {
[INFO] [stderr] 406 | |                     &Num(n) => n as i32,
[INFO] [stderr] 407 | |                     _ => return Err(not_a_number(code))
[INFO] [stderr] 408 | |                 }
[INFO] [stderr]     | |_________________^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 405 |                 match *code {
[INFO] [stderr] 406 |                     Num(n) => n as i32,
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/intrinsics.rs:445:13
[INFO] [stderr]     |
[INFO] [stderr] 445 | /             match arg {
[INFO] [stderr] 446 | |                 &Num(num) => sum += num,
[INFO] [stderr] 447 | |                 _ => return Err(not_a_number(arg))
[INFO] [stderr] 448 | |             }
[INFO] [stderr]     | |_____________^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 445 |             match *arg {
[INFO] [stderr] 446 |                 Num(num) => sum += num,
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/intrinsics.rs:461:13
[INFO] [stderr]     |
[INFO] [stderr] 461 | /             match first {
[INFO] [stderr] 462 | |                 &Num(n) => {
[INFO] [stderr] 463 | |                     if len == 1 {
[INFO] [stderr] 464 | |                         Ok(Num(-n))
[INFO] [stderr] ...   |
[INFO] [stderr] 476 | |                 _ => Err(not_a_number(first))
[INFO] [stderr] 477 | |             }
[INFO] [stderr]     | |_____________^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 461 |             match *first {
[INFO] [stderr] 462 |                 Num(n) => {
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/intrinsics.rs:468:29
[INFO] [stderr]     |
[INFO] [stderr] 468 | /                             match arg {
[INFO] [stderr] 469 | |                                 &Num(num) => acc -= num,
[INFO] [stderr] 470 | |                                 _ => return Err(not_a_number(arg))
[INFO] [stderr] 471 | |                             }
[INFO] [stderr]     | |_____________________________^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 468 |                             match *arg {
[INFO] [stderr] 469 |                                 Num(num) => acc -= num,
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/intrinsics.rs:489:13
[INFO] [stderr]     |
[INFO] [stderr] 489 | /             match arg {
[INFO] [stderr] 490 | |                 &Num(num) => prod *= num,
[INFO] [stderr] 491 | |                 _ => return Err(not_a_number(arg))
[INFO] [stderr] 492 | |             }
[INFO] [stderr]     | |_____________^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 489 |             match *arg {
[INFO] [stderr] 490 |                 Num(num) => prod *= num,
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/intrinsics.rs:505:13
[INFO] [stderr]     |
[INFO] [stderr] 505 | /             match first {
[INFO] [stderr] 506 | |                 &Num(n) => {
[INFO] [stderr] 507 | |                     if len == 1 {
[INFO] [stderr] 508 | |                         Ok(Num(1.0 / n))
[INFO] [stderr] ...   |
[INFO] [stderr] 520 | |                 _ => Err(not_a_number(first))
[INFO] [stderr] 521 | |             }
[INFO] [stderr]     | |_____________^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 505 |             match *first {
[INFO] [stderr] 506 |                 Num(n) => {
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/intrinsics.rs:512:29
[INFO] [stderr]     |
[INFO] [stderr] 512 | /                             match arg {
[INFO] [stderr] 513 | |                                 &Num(num) => acc /= num,
[INFO] [stderr] 514 | |                                 _ => return Err(not_a_number(arg))
[INFO] [stderr] 515 | |                             }
[INFO] [stderr]     | |_____________________________^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 512 |                             match *arg {
[INFO] [stderr] 513 |                                 Num(num) => acc /= num,
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: useless use of `format!`
[INFO] [stderr]    --> src/intrinsics.rs:536:22
[INFO] [stderr]     |
[INFO] [stderr] 536 |             _ => Err(format!("\"modulo\" must be passed nums."))
[INFO] [stderr]     |                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using .to_string(): `"\"modulo\" must be passed nums.".to_string()`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_format
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/intrinsics.rs:547:9
[INFO] [stderr]     |
[INFO] [stderr] 547 | /         match a {
[INFO] [stderr] 548 | |             &Num(a) => ok(f64::sqrt(a)),
[INFO] [stderr] 549 | |             _ => Err(format!("\"sqrt\" must be passed a num."))
[INFO] [stderr] 550 | |         }
[INFO] [stderr]     | |_________^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 547 |         match *a {
[INFO] [stderr] 548 |             Num(a) => ok(f64::sqrt(a)),
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: useless use of `format!`
[INFO] [stderr]    --> src/intrinsics.rs:549:22
[INFO] [stderr]     |
[INFO] [stderr] 549 |             _ => Err(format!("\"sqrt\" must be passed a num."))
[INFO] [stderr]     |                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using .to_string(): `"\"sqrt\" must be passed a num.".to_string()`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_format
[INFO] [stderr] 
[INFO] [stderr] warning: useless use of `format!`
[INFO] [stderr]    --> src/intrinsics.rs:563:22
[INFO] [stderr]     |
[INFO] [stderr] 563 |             _ => Err(format!("\"pow\" must be passed nums."))
[INFO] [stderr]     |                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using .to_string(): `"\"pow\" must be passed nums.".to_string()`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_format
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/intrinsics.rs:574:9
[INFO] [stderr]     |
[INFO] [stderr] 574 | /         match arg {
[INFO] [stderr] 575 | |             &Num(_) => ok(true),
[INFO] [stderr] 576 | |             _ => ok(false)
[INFO] [stderr] 577 | |         }
[INFO] [stderr]     | |_________^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 574 |         match *arg {
[INFO] [stderr] 575 |             Num(_) => ok(true),
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/intrinsics.rs:587:9
[INFO] [stderr]     |
[INFO] [stderr] 587 | /         match arg {
[INFO] [stderr] 588 | |             &Bool(_) => ok(true),
[INFO] [stderr] 589 | |             _ => ok(false)
[INFO] [stderr] 590 | |         }
[INFO] [stderr]     | |_________^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 587 |         match *arg {
[INFO] [stderr] 588 |             Bool(_) => ok(true),
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/intrinsics.rs:600:9
[INFO] [stderr]     |
[INFO] [stderr] 600 | /         match arg {
[INFO] [stderr] 601 | |             &Str(_) => ok(true),
[INFO] [stderr] 602 | |             _ => ok(false)
[INFO] [stderr] 603 | |         }
[INFO] [stderr]     | |_________^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 600 |         match *arg {
[INFO] [stderr] 601 |             Str(_) => ok(true),
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/intrinsics.rs:613:9
[INFO] [stderr]     |
[INFO] [stderr] 613 | /         match arg {
[INFO] [stderr] 614 | |             &List(_) => ok(true),
[INFO] [stderr] 615 | |             _ => ok(false)
[INFO] [stderr] 616 | |         }
[INFO] [stderr]     | |_________^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 613 |         match *arg {
[INFO] [stderr] 614 |             List(_) => ok(true),
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/intrinsics.rs:626:9
[INFO] [stderr]     |
[INFO] [stderr] 626 | /         match arg {
[INFO] [stderr] 627 | |             &Intrinsic(_) => ok(true),
[INFO] [stderr] 628 | |             &Func(_, _) => ok(true),
[INFO] [stderr] 629 | |             _ => ok(false)
[INFO] [stderr] 630 | |         }
[INFO] [stderr]     | |_________^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 626 |         match *arg {
[INFO] [stderr] 627 |             Intrinsic(_) => ok(true),
[INFO] [stderr] 628 |             Func(_, _) => ok(true),
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/intrinsics.rs:671:9
[INFO] [stderr]     |
[INFO] [stderr] 671 | /         match list {
[INFO] [stderr] 672 | |             &List(ref vals) => {
[INFO] [stderr] 673 | |                 let len = vals.len();
[INFO] [stderr] 674 | |                 if len == 0 {
[INFO] [stderr] ...   |
[INFO] [stderr] 680 | |             _ => Err(format!("{} is not a list.", list))
[INFO] [stderr] 681 | |         }
[INFO] [stderr]     | |_________^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 671 |         match *list {
[INFO] [stderr] 672 |             List(ref vals) => {
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: useless use of `format!`
[INFO] [stderr]    --> src/intrinsics.rs:675:25
[INFO] [stderr]     |
[INFO] [stderr] 675 |                     Err(format!("Cannot call car on an empty list."))
[INFO] [stderr]     |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using .to_string(): `"Cannot call car on an empty list.".to_string()`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_format
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/intrinsics.rs:691:9
[INFO] [stderr]     |
[INFO] [stderr] 691 | /         match list {
[INFO] [stderr] 692 | |             &List(ref vals) => {
[INFO] [stderr] 693 | |                 let len = vals.len();
[INFO] [stderr] 694 | |                 if len == 0 {
[INFO] [stderr] ...   |
[INFO] [stderr] 706 | |             _ => Err(format!("{} is not a list.", list))
[INFO] [stderr] 707 | |         }
[INFO] [stderr]     | |_________^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 691 |         match *list {
[INFO] [stderr] 692 |             List(ref vals) => {
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: useless use of `format!`
[INFO] [stderr]    --> src/intrinsics.rs:695:25
[INFO] [stderr]     |
[INFO] [stderr] 695 |                     Err(format!("Cannot call cdr on an empty list."))
[INFO] [stderr]     |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using .to_string(): `"Cannot call cdr on an empty list.".to_string()`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_format
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/intrinsics.rs:717:9
[INFO] [stderr]     |
[INFO] [stderr] 717 | /         match list {
[INFO] [stderr] 718 | |             &List(ref vals) => ok(vals.len() as f64),
[INFO] [stderr] 719 | |             _ => Err(format!("{} is not a list.", list))
[INFO] [stderr] 720 | |         }
[INFO] [stderr]     | |_________^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 717 |         match *list {
[INFO] [stderr] 718 |             List(ref vals) => ok(vals.len() as f64),
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: useless use of `format!`
[INFO] [stderr]    --> src/intrinsics.rs:802:22
[INFO] [stderr]     |
[INFO] [stderr] 802 |             _ => Err(format!("\"or\" may only be called on bool values."))
[INFO] [stderr]     |                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using .to_string(): `"\"or\" may only be called on bool values.".to_string()`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_format
[INFO] [stderr] 
[INFO] [stderr] warning: useless use of `format!`
[INFO] [stderr]    --> src/intrinsics.rs:814:22
[INFO] [stderr]     |
[INFO] [stderr] 814 |             _ => Err(format!("\"and\" may only be called on bool values."))
[INFO] [stderr]     |                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using .to_string(): `"\"and\" may only be called on bool values.".to_string()`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_format
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/intrinsics.rs:840:9
[INFO] [stderr]     |
[INFO] [stderr] 840 | /         match arg {
[INFO] [stderr] 841 | |             &Bool(b) => ok(!b),
[INFO] [stderr] 842 | |             _ => Err(format!("{} is not a bool.", arg))
[INFO] [stderr] 843 | |         }
[INFO] [stderr]     | |_________^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 840 |         match *arg {
[INFO] [stderr] 841 |             Bool(b) => ok(!b),
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `parse_from_str`
[INFO] [stderr]   --> src/parser.rs:18:5
[INFO] [stderr]    |
[INFO] [stderr] 18 |     pub fn parse_from_str(&mut self, s: &str) -> Parse {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(dead_code)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `peak_char`
[INFO] [stderr]    --> src/parser.rs:170:5
[INFO] [stderr]     |
[INFO] [stderr] 170 |     fn peak_char<R: Read>(&mut self, r: &mut BufReader<R>) -> Option<char> {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: constant item is never used: `FIELD_NAMES_FORMAT`
[INFO] [stderr]   --> src/intrinsics.rs:17:1
[INFO] [stderr]    |
[INFO] [stderr] 17 | const FIELD_NAMES_FORMAT: &'static str = "{}-field-names";
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `cur_scope`
[INFO] [stderr]   --> src/environment.rs:17:5
[INFO] [stderr]    |
[INFO] [stderr] 17 |     fn cur_scope(&self) -> &HashMap<String, Value> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]   --> src/values.rs:22:9
[INFO] [stderr]    |
[INFO] [stderr] 22 | /         match self {
[INFO] [stderr] 23 | |             // num
[INFO] [stderr] 24 | |             &Num(n) => write!(f, "{}", n),
[INFO] [stderr] 25 | |
[INFO] [stderr] ...  |
[INFO] [stderr] 93 | |             }
[INFO] [stderr] 94 | |         }
[INFO] [stderr]    | |_________^
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]    |
[INFO] [stderr] 22 |         match *self {
[INFO] [stderr] 23 |             // num
[INFO] [stderr] 24 |             Num(n) => write!(f, "{}", n),
[INFO] [stderr] 25 | 
[INFO] [stderr] 26 |             // #t | #f
[INFO] [stderr] 27 |             Bool(b) => if b {
[INFO] [stderr]  ...
[INFO] [stderr] 
[INFO] [stderr] warning: the loop variable `i` is only used to index `exps`.
[INFO] [stderr]   --> src/values.rs:41:30
[INFO] [stderr]    |
[INFO] [stderr] 41 |                     for i in 0..len - 1 {
[INFO] [stderr]    |                              ^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_range_loop
[INFO] [stderr] help: consider using an iterator
[INFO] [stderr]    |
[INFO] [stderr] 41 |                     for <item> in exps.iter().take(len - 1) {
[INFO] [stderr]    |                         ^^^^^^    ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: the loop variable `i` is only used to index `args`.
[INFO] [stderr]   --> src/values.rs:57:30
[INFO] [stderr]    |
[INFO] [stderr] 57 |                     for i in 0..args.len() - 1 {
[INFO] [stderr]    |                              ^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_range_loop
[INFO] [stderr] help: consider using an iterator
[INFO] [stderr]    |
[INFO] [stderr] 57 |                     for <item> in args.iter().take(args.len() - 1) {
[INFO] [stderr]    |                         ^^^^^^    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: you should consider deriving a `Default` implementation for `environment::Environment`
[INFO] [stderr]   --> src/environment.rs:9:5
[INFO] [stderr]    |
[INFO] [stderr] 9  | /     pub fn new() -> Environment {
[INFO] [stderr] 10 | |         let mut env = Environment {
[INFO] [stderr] 11 | |             stack: vec![]
[INFO] [stderr] 12 | |         };
[INFO] [stderr] 13 | |         env.enter_scope();
[INFO] [stderr] 14 | |         env
[INFO] [stderr] 15 | |     }
[INFO] [stderr]    | |_____^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::new_without_default_derive)] on by default
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#new_without_default_derive
[INFO] [stderr] help: try this
[INFO] [stderr]    |
[INFO] [stderr] 4  | #[derive(Default)]
[INFO] [stderr]    |
[INFO] [stderr] 
[INFO] [stderr] warning: the loop variable `i` is only used to index `exps`.
[INFO] [stderr]   --> src/sexpr.rs:38:30
[INFO] [stderr]    |
[INFO] [stderr] 38 |                     for i in 0..len - 1 {
[INFO] [stderr]    |                              ^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::needless_range_loop)] on by default
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_range_loop
[INFO] [stderr] help: consider using an iterator
[INFO] [stderr]    |
[INFO] [stderr] 38 |                     for <item> in exps.iter().take(len - 1) {
[INFO] [stderr]    |                         ^^^^^^    ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: length comparison to zero
[INFO] [stderr]   --> src/main.rs:85:43
[INFO] [stderr]    |
[INFO] [stderr] 85 |                     Value::List(ref l) if l.len() == 0 => continue,
[INFO] [stderr]    |                                           ^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `l.is_empty()`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::len_zero)] on by default
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#len_zero
[INFO] [stderr] 
[INFO] [stderr] warning: useless use of `format!`
[INFO] [stderr]    --> src/intrinsics.rs:141:29
[INFO] [stderr]     |
[INFO] [stderr] 141 |                         Err(format!("Cannot redefine empty list."))
[INFO] [stderr]     |                             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using .to_string(): `"Cannot redefine empty list.".to_string()`
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(clippy::useless_format)] on by default
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_format
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/intrinsics.rs:185:21
[INFO] [stderr]     |
[INFO] [stderr] 185 | /                     match param {
[INFO] [stderr] 186 | |                         &SExpr::Ident(ref s) => names.push(s.to_string()),
[INFO] [stderr] 187 | |                         _ => return Err(not_an_identifier(param))
[INFO] [stderr] 188 | |                     }
[INFO] [stderr]     | |_____________________^
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(clippy::match_ref_pats)] on by default
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 185 |                     match *param {
[INFO] [stderr] 186 |                         SExpr::Ident(ref s) => names.push(s.to_string()),
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: useless use of `format!`
[INFO] [stderr]    --> src/intrinsics.rs:366:37
[INFO] [stderr]     |
[INFO] [stderr] 366 |                                 Err(format!("hi"))
[INFO] [stderr]     |                                     ^^^^^^^^^^^^^ help: consider using .to_string(): `"hi".to_string()`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_format
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/intrinsics.rs:405:17
[INFO] [stderr]     |
[INFO] [stderr] 405 | /                 match code {
[INFO] [stderr] 406 | |                     &Num(n) => n as i32,
[INFO] [stderr] 407 | |                     _ => return Err(not_a_number(code))
[INFO] [stderr] 408 | |                 }
[INFO] [stderr]     | |_________________^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 405 |                 match *code {
[INFO] [stderr] 406 |                     Num(n) => n as i32,
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/intrinsics.rs:445:13
[INFO] [stderr]     |
[INFO] [stderr] 445 | /             match arg {
[INFO] [stderr] 446 | |                 &Num(num) => sum += num,
[INFO] [stderr] 447 | |                 _ => return Err(not_a_number(arg))
[INFO] [stderr] 448 | |             }
[INFO] [stderr]     | |_____________^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 445 |             match *arg {
[INFO] [stderr] 446 |                 Num(num) => sum += num,
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/intrinsics.rs:461:13
[INFO] [stderr]     |
[INFO] [stderr] 461 | /             match first {
[INFO] [stderr] 462 | |                 &Num(n) => {
[INFO] [stderr] 463 | |                     if len == 1 {
[INFO] [stderr] 464 | |                         Ok(Num(-n))
[INFO] [stderr] ...   |
[INFO] [stderr] 476 | |                 _ => Err(not_a_number(first))
[INFO] [stderr] 477 | |             }
[INFO] [stderr]     | |_____________^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 461 |             match *first {
[INFO] [stderr] 462 |                 Num(n) => {
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/intrinsics.rs:468:29
[INFO] [stderr]     |
[INFO] [stderr] 468 | /                             match arg {
[INFO] [stderr] 469 | |                                 &Num(num) => acc -= num,
[INFO] [stderr] 470 | |                                 _ => return Err(not_a_number(arg))
[INFO] [stderr] 471 | |                             }
[INFO] [stderr]     | |_____________________________^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 468 |                             match *arg {
[INFO] [stderr] 469 |                                 Num(num) => acc -= num,
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/intrinsics.rs:489:13
[INFO] [stderr]     |
[INFO] [stderr] 489 | /             match arg {
[INFO] [stderr] 490 | |                 &Num(num) => prod *= num,
[INFO] [stderr] 491 | |                 _ => return Err(not_a_number(arg))
[INFO] [stderr] 492 | |             }
[INFO] [stderr]     | |_____________^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 489 |             match *arg {
[INFO] [stderr] 490 |                 Num(num) => prod *= num,
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/intrinsics.rs:505:13
[INFO] [stderr]     |
[INFO] [stderr] 505 | /             match first {
[INFO] [stderr] 506 | |                 &Num(n) => {
[INFO] [stderr] 507 | |                     if len == 1 {
[INFO] [stderr] 508 | |                         Ok(Num(1.0 / n))
[INFO] [stderr] ...   |
[INFO] [stderr] 520 | |                 _ => Err(not_a_number(first))
[INFO] [stderr] 521 | |             }
[INFO] [stderr]     | |_____________^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 505 |             match *first {
[INFO] [stderr] 506 |                 Num(n) => {
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/intrinsics.rs:512:29
[INFO] [stderr]     |
[INFO] [stderr] 512 | /                             match arg {
[INFO] [stderr] 513 | |                                 &Num(num) => acc /= num,
[INFO] [stderr] 514 | |                                 _ => return Err(not_a_number(arg))
[INFO] [stderr] 515 | |                             }
[INFO] [stderr]     | |_____________________________^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 512 |                             match *arg {
[INFO] [stderr] 513 |                                 Num(num) => acc /= num,
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: useless use of `format!`
[INFO] [stderr]    --> src/intrinsics.rs:536:22
[INFO] [stderr]     |
[INFO] [stderr] 536 |             _ => Err(format!("\"modulo\" must be passed nums."))
[INFO] [stderr]     |                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using .to_string(): `"\"modulo\" must be passed nums.".to_string()`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_format
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/intrinsics.rs:547:9
[INFO] [stderr]     |
[INFO] [stderr] 547 | /         match a {
[INFO] [stderr] 548 | |             &Num(a) => ok(f64::sqrt(a)),
[INFO] [stderr] 549 | |             _ => Err(format!("\"sqrt\" must be passed a num."))
[INFO] [stderr] 550 | |         }
[INFO] [stderr]     | |_________^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 547 |         match *a {
[INFO] [stderr] 548 |             Num(a) => ok(f64::sqrt(a)),
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: useless use of `format!`
[INFO] [stderr]    --> src/intrinsics.rs:549:22
[INFO] [stderr]     |
[INFO] [stderr] 549 |             _ => Err(format!("\"sqrt\" must be passed a num."))
[INFO] [stderr]     |                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using .to_string(): `"\"sqrt\" must be passed a num.".to_string()`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_format
[INFO] [stderr] 
[INFO] [stderr] warning: useless use of `format!`
[INFO] [stderr]    --> src/intrinsics.rs:563:22
[INFO] [stderr]     |
[INFO] [stderr] 563 |             _ => Err(format!("\"pow\" must be passed nums."))
[INFO] [stderr]     |                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using .to_string(): `"\"pow\" must be passed nums.".to_string()`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_format
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/intrinsics.rs:574:9
[INFO] [stderr]     |
[INFO] [stderr] 574 | /         match arg {
[INFO] [stderr] 575 | |             &Num(_) => ok(true),
[INFO] [stderr] 576 | |             _ => ok(false)
[INFO] [stderr] 577 | |         }
[INFO] [stderr]     | |_________^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 574 |         match *arg {
[INFO] [stderr] 575 |             Num(_) => ok(true),
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/intrinsics.rs:587:9
[INFO] [stderr]     |
[INFO] [stderr] 587 | /         match arg {
[INFO] [stderr] 588 | |             &Bool(_) => ok(true),
[INFO] [stderr] 589 | |             _ => ok(false)
[INFO] [stderr] 590 | |         }
[INFO] [stderr]     | |_________^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 587 |         match *arg {
[INFO] [stderr] 588 |             Bool(_) => ok(true),
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/intrinsics.rs:600:9
[INFO] [stderr]     |
[INFO] [stderr] 600 | /         match arg {
[INFO] [stderr] 601 | |             &Str(_) => ok(true),
[INFO] [stderr] 602 | |             _ => ok(false)
[INFO] [stderr] 603 | |         }
[INFO] [stderr]     | |_________^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 600 |         match *arg {
[INFO] [stderr] 601 |             Str(_) => ok(true),
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/intrinsics.rs:613:9
[INFO] [stderr]     |
[INFO] [stderr] 613 | /         match arg {
[INFO] [stderr] 614 | |             &List(_) => ok(true),
[INFO] [stderr] 615 | |             _ => ok(false)
[INFO] [stderr] 616 | |         }
[INFO] [stderr]     | |_________^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 613 |         match *arg {
[INFO] [stderr] 614 |             List(_) => ok(true),
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/intrinsics.rs:626:9
[INFO] [stderr]     |
[INFO] [stderr] 626 | /         match arg {
[INFO] [stderr] 627 | |             &Intrinsic(_) => ok(true),
[INFO] [stderr] 628 | |             &Func(_, _) => ok(true),
[INFO] [stderr] 629 | |             _ => ok(false)
[INFO] [stderr] 630 | |         }
[INFO] [stderr]     | |_________^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 626 |         match *arg {
[INFO] [stderr] 627 |             Intrinsic(_) => ok(true),
[INFO] [stderr] 628 |             Func(_, _) => ok(true),
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/intrinsics.rs:671:9
[INFO] [stderr]     |
[INFO] [stderr] 671 | /         match list {
[INFO] [stderr] 672 | |             &List(ref vals) => {
[INFO] [stderr] 673 | |                 let len = vals.len();
[INFO] [stderr] 674 | |                 if len == 0 {
[INFO] [stderr] ...   |
[INFO] [stderr] 680 | |             _ => Err(format!("{} is not a list.", list))
[INFO] [stderr] 681 | |         }
[INFO] [stderr]     | |_________^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 671 |         match *list {
[INFO] [stderr] 672 |             List(ref vals) => {
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: useless use of `format!`
[INFO] [stderr]    --> src/intrinsics.rs:675:25
[INFO] [stderr]     |
[INFO] [stderr] 675 |                     Err(format!("Cannot call car on an empty list."))
[INFO] [stderr]     |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using .to_string(): `"Cannot call car on an empty list.".to_string()`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_format
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/intrinsics.rs:691:9
[INFO] [stderr]     |
[INFO] [stderr] 691 | /         match list {
[INFO] [stderr] 692 | |             &List(ref vals) => {
[INFO] [stderr] 693 | |                 let len = vals.len();
[INFO] [stderr] 694 | |                 if len == 0 {
[INFO] [stderr] ...   |
[INFO] [stderr] 706 | |             _ => Err(format!("{} is not a list.", list))
[INFO] [stderr] 707 | |         }
[INFO] [stderr]     | |_________^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 691 |         match *list {
[INFO] [stderr] 692 |             List(ref vals) => {
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: useless use of `format!`
[INFO] [stderr]    --> src/intrinsics.rs:695:25
[INFO] [stderr]     |
[INFO] [stderr] 695 |                     Err(format!("Cannot call cdr on an empty list."))
[INFO] [stderr]     |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using .to_string(): `"Cannot call cdr on an empty list.".to_string()`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_format
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/intrinsics.rs:717:9
[INFO] [stderr]     |
[INFO] [stderr] 717 | /         match list {
[INFO] [stderr] 718 | |             &List(ref vals) => ok(vals.len() as f64),
[INFO] [stderr] 719 | |             _ => Err(format!("{} is not a list.", list))
[INFO] [stderr] 720 | |         }
[INFO] [stderr]     | |_________^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 717 |         match *list {
[INFO] [stderr] 718 |             List(ref vals) => ok(vals.len() as f64),
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: useless use of `format!`
[INFO] [stderr]    --> src/intrinsics.rs:802:22
[INFO] [stderr]     |
[INFO] [stderr] 802 |             _ => Err(format!("\"or\" may only be called on bool values."))
[INFO] [stderr]     |                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using .to_string(): `"\"or\" may only be called on bool values.".to_string()`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_format
[INFO] [stderr] 
[INFO] [stderr] warning: useless use of `format!`
[INFO] [stderr]    --> src/intrinsics.rs:814:22
[INFO] [stderr]     |
[INFO] [stderr] 814 |             _ => Err(format!("\"and\" may only be called on bool values."))
[INFO] [stderr]     |                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider using .to_string(): `"\"and\" may only be called on bool values.".to_string()`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_format
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/intrinsics.rs:840:9
[INFO] [stderr]     |
[INFO] [stderr] 840 | /         match arg {
[INFO] [stderr] 841 | |             &Bool(b) => ok(!b),
[INFO] [stderr] 842 | |             _ => Err(format!("{} is not a bool.", arg))
[INFO] [stderr] 843 | |         }
[INFO] [stderr]     | |_________^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 840 |         match *arg {
[INFO] [stderr] 841 |             Bool(b) => ok(!b),
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]   --> src/values.rs:22:9
[INFO] [stderr]    |
[INFO] [stderr] 22 | /         match self {
[INFO] [stderr] 23 | |             // num
[INFO] [stderr] 24 | |             &Num(n) => write!(f, "{}", n),
[INFO] [stderr] 25 | |
[INFO] [stderr] ...  |
[INFO] [stderr] 93 | |             }
[INFO] [stderr] 94 | |         }
[INFO] [stderr]    | |_________^
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]    |
[INFO] [stderr] 22 |         match *self {
[INFO] [stderr] 23 |             // num
[INFO] [stderr] 24 |             Num(n) => write!(f, "{}", n),
[INFO] [stderr] 25 | 
[INFO] [stderr] 26 |             // #t | #f
[INFO] [stderr] 27 |             Bool(b) => if b {
[INFO] [stderr]  ...
[INFO] [stderr] 
[INFO] [stderr] warning: the loop variable `i` is only used to index `exps`.
[INFO] [stderr]   --> src/values.rs:41:30
[INFO] [stderr]    |
[INFO] [stderr] 41 |                     for i in 0..len - 1 {
[INFO] [stderr]    |                              ^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_range_loop
[INFO] [stderr] help: consider using an iterator
[INFO] [stderr]    |
[INFO] [stderr] 41 |                     for <item> in exps.iter().take(len - 1) {
[INFO] [stderr]    |                         ^^^^^^    ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: the loop variable `i` is only used to index `args`.
[INFO] [stderr]   --> src/values.rs:57:30
[INFO] [stderr]    |
[INFO] [stderr] 57 |                     for i in 0..args.len() - 1 {
[INFO] [stderr]    |                              ^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_range_loop
[INFO] [stderr] help: consider using an iterator
[INFO] [stderr]    |
[INFO] [stderr] 57 |                     for <item> in args.iter().take(args.len() - 1) {
[INFO] [stderr]    |                         ^^^^^^    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: you should consider deriving a `Default` implementation for `environment::Environment`
[INFO] [stderr]   --> src/environment.rs:9:5
[INFO] [stderr]    |
[INFO] [stderr] 9  | /     pub fn new() -> Environment {
[INFO] [stderr] 10 | |         let mut env = Environment {
[INFO] [stderr] 11 | |             stack: vec![]
[INFO] [stderr] 12 | |         };
[INFO] [stderr] 13 | |         env.enter_scope();
[INFO] [stderr] 14 | |         env
[INFO] [stderr] 15 | |     }
[INFO] [stderr]    | |_____^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::new_without_default_derive)] on by default
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#new_without_default_derive
[INFO] [stderr] help: try this
[INFO] [stderr]    |
[INFO] [stderr] 4  | #[derive(Default)]
[INFO] [stderr]    |
[INFO] [stderr] 
[INFO] [stderr] warning: length comparison to zero
[INFO] [stderr]   --> src/main.rs:85:43
[INFO] [stderr]    |
[INFO] [stderr] 85 |                     Value::List(ref l) if l.len() == 0 => continue,
[INFO] [stderr]    |                                           ^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `l.is_empty()`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::len_zero)] on by default
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#len_zero
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.19s
[INFO] running `"docker" "inspect" "a8f83a5815c0dcd8316fa95144c802931446b08de0b61df82118d4f07b2d49db"`
[INFO] running `"docker" "rm" "-f" "a8f83a5815c0dcd8316fa95144c802931446b08de0b61df82118d4f07b2d49db"`
[INFO] [stdout] a8f83a5815c0dcd8316fa95144c802931446b08de0b61df82118d4f07b2d49db