[INFO] updating cached repository sampullman/rust-scheme
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/sampullman/rust-scheme
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/sampullman/rust-scheme" "work/ex/clippy-test-run/sources/stable/gh/sampullman/rust-scheme"`
[INFO] [stderr] Cloning into 'work/ex/clippy-test-run/sources/stable/gh/sampullman/rust-scheme'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/sampullman/rust-scheme" "work/ex/clippy-test-run/sources/stable+rustflags=-Dclippy%3A%3Ainto_iter_on_array/gh/sampullman/rust-scheme"`
[INFO] [stderr] Cloning into 'work/ex/clippy-test-run/sources/stable+rustflags=-Dclippy%3A%3Ainto_iter_on_array/gh/sampullman/rust-scheme'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] f9bd7aa53c119bf21693606a480d7bc76c18badb
[INFO] sha for GitHub repo sampullman/rust-scheme: f9bd7aa53c119bf21693606a480d7bc76c18badb
[INFO] validating manifest of sampullman/rust-scheme 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 sampullman/rust-scheme 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 sampullman/rust-scheme
[INFO] finished frobbing sampullman/rust-scheme
[INFO] frobbed toml for sampullman/rust-scheme written to work/ex/clippy-test-run/sources/stable/gh/sampullman/rust-scheme/Cargo.toml
[INFO] started frobbing sampullman/rust-scheme
[INFO] finished frobbing sampullman/rust-scheme
[INFO] frobbed toml for sampullman/rust-scheme written to work/ex/clippy-test-run/sources/stable+rustflags=-Dclippy%3A%3Ainto_iter_on_array/gh/sampullman/rust-scheme/Cargo.toml
[INFO] crate sampullman/rust-scheme 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 sampullman/rust-scheme against stable for clippy-test-run
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/clippy-test-run/worker-1/stable:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/clippy-test-run/sources/stable/gh/sampullman/rust-scheme:/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" "-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] f70b4273d45950bf3e59cfdac91a376103c4a07fc217aee3349fc729aad15ab7
[INFO] running `"docker" "start" "-a" "f70b4273d45950bf3e59cfdac91a376103c4a07fc217aee3349fc729aad15ab7"`
[INFO] [stderr]     Checking rust-scheme v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: redundant field names in struct initialization
[INFO] [stderr]   --> src/environment.rs:45:23
[INFO] [stderr]    |
[INFO] [stderr] 45 |         SchemeLambda {name: name, arg_list: arg_list, body: body}
[INFO] [stderr]    |                       ^^^^^^^^^^ help: replace it with: `name`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::redundant_field_names)] on by default
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_field_names
[INFO] [stderr] 
[INFO] [stderr] warning: redundant field names in struct initialization
[INFO] [stderr]   --> src/environment.rs:45:35
[INFO] [stderr]    |
[INFO] [stderr] 45 |         SchemeLambda {name: name, arg_list: arg_list, body: body}
[INFO] [stderr]    |                                   ^^^^^^^^^^^^^^^^^^ help: replace it with: `arg_list`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_field_names
[INFO] [stderr] 
[INFO] [stderr] warning: redundant field names in struct initialization
[INFO] [stderr]   --> src/environment.rs:45:55
[INFO] [stderr]    |
[INFO] [stderr] 45 |         SchemeLambda {name: name, arg_list: arg_list, body: body}
[INFO] [stderr]    |                                                       ^^^^^^^^^^ help: replace it with: `body`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_field_names
[INFO] [stderr] 
[INFO] [stderr] warning: redundant field names in struct initialization
[INFO] [stderr]   --> src/interpreter.rs:75:102
[INFO] [stderr]    |
[INFO] [stderr] 75 |             let lambda = SchemeFnWrap::Lambda(SchemeLambda {name: name.clone(), arg_list: arg_names, body: body});
[INFO] [stderr]    |                                                                                                      ^^^^^^^^^^ help: replace it with: `body`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_field_names
[INFO] [stderr] 
[INFO] [stderr] warning: redundant field names in struct initialization
[INFO] [stderr]   --> src/environment.rs:45:23
[INFO] [stderr]    |
[INFO] [stderr] 45 |         SchemeLambda {name: name, arg_list: arg_list, body: body}
[INFO] [stderr]    |                       ^^^^^^^^^^ help: replace it with: `name`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::redundant_field_names)] on by default
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_field_names
[INFO] [stderr] 
[INFO] [stderr] warning: redundant field names in struct initialization
[INFO] [stderr]   --> src/environment.rs:45:35
[INFO] [stderr]    |
[INFO] [stderr] 45 |         SchemeLambda {name: name, arg_list: arg_list, body: body}
[INFO] [stderr]    |                                   ^^^^^^^^^^^^^^^^^^ help: replace it with: `arg_list`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_field_names
[INFO] [stderr] 
[INFO] [stderr] warning: redundant field names in struct initialization
[INFO] [stderr]   --> src/environment.rs:45:55
[INFO] [stderr]    |
[INFO] [stderr] 45 |         SchemeLambda {name: name, arg_list: arg_list, body: body}
[INFO] [stderr]    |                                                       ^^^^^^^^^^ help: replace it with: `body`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_field_names
[INFO] [stderr] 
[INFO] [stderr] warning: redundant field names in struct initialization
[INFO] [stderr]   --> src/interpreter.rs:75:102
[INFO] [stderr]    |
[INFO] [stderr] 75 |             let lambda = SchemeFnWrap::Lambda(SchemeLambda {name: name.clone(), arg_list: arg_names, body: body});
[INFO] [stderr]    |                                                                                                      ^^^^^^^^^^ help: replace it with: `body`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_field_names
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]  --> src/builtins.rs:9:5
[INFO] [stderr]   |
[INFO] [stderr] 9 |     return Ok(Atom::Int(args.iter().filter_map(|a| a.as_int()).fold(0, |a, b| a + b)));
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Ok(Atom::Int(args.iter().filter_map(|a| a.as_int()).fold(0, |a, b| a + b)))`
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(clippy::needless_return)] on by default
[INFO] [stderr]   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/builtins.rs:13:5
[INFO] [stderr]    |
[INFO] [stderr] 13 |     return Ok(Atom::Int(args.iter().filter_map(|a| a.as_int()).fold(1, |a, b| a * b)));
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Ok(Atom::Int(args.iter().filter_map(|a| a.as_int()).fold(1, |a, b| a * b)))`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/builtins.rs:18:9
[INFO] [stderr]    |
[INFO] [stderr] 18 |         return Err(format!("Invalid number of operands to subtract {}", args.len()));
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Err(format!("Invalid number of operands to subtract {}", args.len()))`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/builtins.rs:22:9
[INFO] [stderr]    |
[INFO] [stderr] 22 |         return Ok(Atom::Int(arg1 - arg2));
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Ok(Atom::Int(arg1 - arg2))`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/builtins.rs:28:9
[INFO] [stderr]    |
[INFO] [stderr] 28 |         return Err(format!("Invalid number of operands to divide {}", args.len()));
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Err(format!("Invalid number of operands to divide {}", args.len()))`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/builtins.rs:32:9
[INFO] [stderr]    |
[INFO] [stderr] 32 |         return Ok(Atom::Int(arg1 / arg2));
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Ok(Atom::Int(arg1 / arg2))`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/builtins.rs:38:9
[INFO] [stderr]    |
[INFO] [stderr] 38 |         return Err(format!("Invalid number of operands to > {}", args.len()));
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Err(format!("Invalid number of operands to > {}", args.len()))`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/builtins.rs:42:9
[INFO] [stderr]    |
[INFO] [stderr] 42 |         return Ok(Atom::Bool(arg1 > arg2));
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Ok(Atom::Bool(arg1 > arg2))`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/builtins.rs:48:9
[INFO] [stderr]    |
[INFO] [stderr] 48 |         return Err(format!("Invalid number of operands to < {}", args.len()));
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Err(format!("Invalid number of operands to < {}", args.len()))`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/builtins.rs:52:9
[INFO] [stderr]    |
[INFO] [stderr] 52 |         return Ok(Atom::Bool(arg1 < arg2));
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Ok(Atom::Bool(arg1 < arg2))`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/builtins.rs:58:9
[INFO] [stderr]    |
[INFO] [stderr] 58 |         return Err(format!("Invalid number of operands to >= {}", args.len()));
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Err(format!("Invalid number of operands to >= {}", args.len()))`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/builtins.rs:62:9
[INFO] [stderr]    |
[INFO] [stderr] 62 |         return Ok(Atom::Bool(arg1 >= arg2));
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Ok(Atom::Bool(arg1 >= arg2))`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/builtins.rs:68:9
[INFO] [stderr]    |
[INFO] [stderr] 68 |         return Err(format!("Invalid number of operands to <= {}", args.len()));
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Err(format!("Invalid number of operands to <= {}", args.len()))`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/builtins.rs:72:9
[INFO] [stderr]    |
[INFO] [stderr] 72 |         return Ok(Atom::Bool(arg1 <= arg2));
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Ok(Atom::Bool(arg1 <= arg2))`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/builtins.rs:78:9
[INFO] [stderr]    |
[INFO] [stderr] 78 |         return Err(format!("Invalid number of operands to = {}", args.len()));
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Err(format!("Invalid number of operands to = {}", args.len()))`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/builtins.rs:82:9
[INFO] [stderr]    |
[INFO] [stderr] 82 |         return Ok(Atom::Bool(arg1 == arg2));
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Ok(Atom::Bool(arg1 == arg2))`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/builtins.rs:88:9
[INFO] [stderr]    |
[INFO] [stderr] 88 |         return Err(format!("Invalid number of operands to abs {}", args.len()));
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Err(format!("Invalid number of operands to abs {}", args.len()))`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/builtins.rs:91:9
[INFO] [stderr]    |
[INFO] [stderr] 91 |         return Ok(Atom::Int(arg.abs()));
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Ok(Atom::Int(arg.abs()))`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/builtins.rs:101:5
[INFO] [stderr]     |
[INFO] [stderr] 101 |     return Ok(Atom::List(l1))
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Ok(Atom::List(l1))`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/builtins.rs:123:5
[INFO] [stderr]     |
[INFO] [stderr] 123 |     return evaluate(iter.last().unwrap_or(Atom::Nil), env)
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `evaluate(iter.last().unwrap_or(Atom::Nil), env)`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/builtins.rs:131:33
[INFO] [stderr]     |
[INFO] [stderr] 131 |         Atom::Cons(car, cdr) => return Ok(*car),
[INFO] [stderr]     |                                 ^^^^^^^^^^^^^^^ help: remove `return` as shown: `Ok(*car)`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/builtins.rs:134:17
[INFO] [stderr]     |
[INFO] [stderr] 134 |                 return Ok(atoms[0].clone())
[INFO] [stderr]     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Ok(atoms[0].clone())`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/builtins.rs:136:17
[INFO] [stderr]     |
[INFO] [stderr] 136 |                 return Err("CAR expects a pair".to_string())
[INFO] [stderr]     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Err("CAR expects a pair".to_string())`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/builtins.rs:139:14
[INFO] [stderr]     |
[INFO] [stderr] 139 |         _ => return Err("CAR expects a pair".to_string())
[INFO] [stderr]     |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Err("CAR expects a pair".to_string())`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/builtins.rs:148:33
[INFO] [stderr]     |
[INFO] [stderr] 148 |         Atom::Cons(car, cdr) => return Ok(*cdr),
[INFO] [stderr]     |                                 ^^^^^^^^^^^^^^^ help: remove `return` as shown: `Ok(*cdr)`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/builtins.rs:151:17
[INFO] [stderr]     |
[INFO] [stderr] 151 |                 return Ok(Atom::List(atoms.into_iter().skip(1).collect()))
[INFO] [stderr]     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Ok(Atom::List(atoms.into_iter().skip(1).collect()))`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/builtins.rs:153:17
[INFO] [stderr]     |
[INFO] [stderr] 153 |                 return Err("CDR expects a pair".to_string())
[INFO] [stderr]     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Err("CDR expects a pair".to_string())`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/builtins.rs:156:14
[INFO] [stderr]     |
[INFO] [stderr] 156 |         _ => return Err("CDR expects a pair".to_string())
[INFO] [stderr]     |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Err("CDR expects a pair".to_string())`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/builtins.rs:162:9
[INFO] [stderr]     |
[INFO] [stderr] 162 |         return Err(format!("Invalid number of operands to cons {}", args.len()))
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Err(format!("Invalid number of operands to cons {}", args.len()))`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/builtins.rs:164:9
[INFO] [stderr]     |
[INFO] [stderr] 164 |         return Ok(Atom::Cons(Box::new(args[0].clone()), Box::new(args[1].clone())))
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Ok(Atom::Cons(Box::new(args[0].clone()), Box::new(args[1].clone())))`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/builtins.rs:171:9
[INFO] [stderr]     |
[INFO] [stderr] 171 |         return Err(format!("Invalid number of operands to eq? {}", args.len()))
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Err(format!("Invalid number of operands to eq? {}", args.len()))`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/builtins.rs:173:9
[INFO] [stderr]     |
[INFO] [stderr] 173 | /         return Ok(Atom::Bool(match &args[0] {
[INFO] [stderr] 174 | |             &Atom::Bool(_) => args[0] == args[1],
[INFO] [stderr] 175 | |             &Atom::Int(_) => args[0] == args[1],
[INFO] [stderr] 176 | |             _ => &args[0] as *const Atom == &args[1] as *const Atom
[INFO] [stderr] 177 | |         }))
[INFO] [stderr]     | |___________^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] help: remove `return` as shown
[INFO] [stderr]     |
[INFO] [stderr] 173 |         Ok(Atom::Bool(match &args[0] {
[INFO] [stderr] 174 |             &Atom::Bool(_) => args[0] == args[1],
[INFO] [stderr] 175 |             &Atom::Int(_) => args[0] == args[1],
[INFO] [stderr] 176 |             _ => &args[0] as *const Atom == &args[1] as *const Atom
[INFO] [stderr] 177 |         }))
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/builtins.rs:183:9
[INFO] [stderr]     |
[INFO] [stderr] 183 |         return Err(format!("Invalid number of operands to equal? {}", args.len()))
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Err(format!("Invalid number of operands to equal? {}", args.len()))`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/builtins.rs:185:9
[INFO] [stderr]     |
[INFO] [stderr] 185 |         return Ok(Atom::Bool(args[0] == args[1]))
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Ok(Atom::Bool(args[0] == args[1]))`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/builtins.rs:195:9
[INFO] [stderr]     |
[INFO] [stderr] 195 |         return Err(format!("Invalid number of operands to equal? {}", args.len()))
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Err(format!("Invalid number of operands to equal? {}", args.len()))`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: this `else { if .. }` block can be collapsed
[INFO] [stderr]    --> src/builtins.rs:196:12
[INFO] [stderr]     |
[INFO] [stderr] 196 |       } else {
[INFO] [stderr]     |  ____________^
[INFO] [stderr] 197 | |         if let Some(_) = args[0].as_list() {
[INFO] [stderr] 198 | |             return Ok(Atom::Bool(true))
[INFO] [stderr] 199 | |         } else {
[INFO] [stderr] 200 | |             return Ok(Atom::Bool(false))
[INFO] [stderr] 201 | |         }
[INFO] [stderr] 202 | |     }
[INFO] [stderr]     | |_____^
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(clippy::collapsible_if)] on by default
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#collapsible_if
[INFO] [stderr] help: try
[INFO] [stderr]     |
[INFO] [stderr] 196 |     } else if let Some(_) = args[0].as_list() {
[INFO] [stderr] 197 |     return Ok(Atom::Bool(true))
[INFO] [stderr] 198 | } else {
[INFO] [stderr] 199 |     return Ok(Atom::Bool(false))
[INFO] [stderr] 200 | }
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: this `else { if .. }` block can be collapsed
[INFO] [stderr]   --> src/interpreter.rs:88:16
[INFO] [stderr]    |
[INFO] [stderr] 88 |           } else {
[INFO] [stderr]    |  ________________^
[INFO] [stderr] 89 | |             if body.len() == 2 {
[INFO] [stderr] 90 | |                 evaluate(body[1].clone(), env)
[INFO] [stderr] 91 | |             } else {
[INFO] [stderr] 92 | |                 Err("Too many arguments to 'if'".to_string())
[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#collapsible_if
[INFO] [stderr] help: try
[INFO] [stderr]    |
[INFO] [stderr] 88 |         } else if body.len() == 2 {
[INFO] [stderr] 89 |     evaluate(body[1].clone(), env)
[INFO] [stderr] 90 | } else {
[INFO] [stderr] 91 |     Err("Too many arguments to 'if'".to_string())
[INFO] [stderr] 92 | }
[INFO] [stderr]    |
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/interpreter.rs:118:5
[INFO] [stderr]     |
[INFO] [stderr] 118 |     return Ok(None)
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^ help: remove `return` as shown: `Ok(None)`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/atom.rs:48:9
[INFO] [stderr]    |
[INFO] [stderr] 48 |         return None
[INFO] [stderr]    |         ^^^^^^^^^^^ help: remove `return` as shown: `None`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]  --> src/builtins.rs:9:5
[INFO] [stderr]   |
[INFO] [stderr] 9 |     return Ok(Atom::Int(args.iter().filter_map(|a| a.as_int()).fold(0, |a, b| a + b)));
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Ok(Atom::Int(args.iter().filter_map(|a| a.as_int()).fold(0, |a, b| a + b)))`
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(clippy::needless_return)] on by default
[INFO] [stderr]   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/builtins.rs:13:5
[INFO] [stderr]    |
[INFO] [stderr] 13 |     return Ok(Atom::Int(args.iter().filter_map(|a| a.as_int()).fold(1, |a, b| a * b)));
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Ok(Atom::Int(args.iter().filter_map(|a| a.as_int()).fold(1, |a, b| a * b)))`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/builtins.rs:18:9
[INFO] [stderr]    |
[INFO] [stderr] 18 |         return Err(format!("Invalid number of operands to subtract {}", args.len()));
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Err(format!("Invalid number of operands to subtract {}", args.len()))`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/builtins.rs:22:9
[INFO] [stderr]    |
[INFO] [stderr] 22 |         return Ok(Atom::Int(arg1 - arg2));
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Ok(Atom::Int(arg1 - arg2))`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/builtins.rs:28:9
[INFO] [stderr]    |
[INFO] [stderr] 28 |         return Err(format!("Invalid number of operands to divide {}", args.len()));
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Err(format!("Invalid number of operands to divide {}", args.len()))`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/builtins.rs:32:9
[INFO] [stderr]    |
[INFO] [stderr] 32 |         return Ok(Atom::Int(arg1 / arg2));
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Ok(Atom::Int(arg1 / arg2))`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/builtins.rs:38:9
[INFO] [stderr]    |
[INFO] [stderr] 38 |         return Err(format!("Invalid number of operands to > {}", args.len()));
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Err(format!("Invalid number of operands to > {}", args.len()))`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/builtins.rs:42:9
[INFO] [stderr]    |
[INFO] [stderr] 42 |         return Ok(Atom::Bool(arg1 > arg2));
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Ok(Atom::Bool(arg1 > arg2))`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/builtins.rs:48:9
[INFO] [stderr]    |
[INFO] [stderr] 48 |         return Err(format!("Invalid number of operands to < {}", args.len()));
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Err(format!("Invalid number of operands to < {}", args.len()))`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/builtins.rs:52:9
[INFO] [stderr]    |
[INFO] [stderr] 52 |         return Ok(Atom::Bool(arg1 < arg2));
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Ok(Atom::Bool(arg1 < arg2))`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/builtins.rs:58:9
[INFO] [stderr]    |
[INFO] [stderr] 58 |         return Err(format!("Invalid number of operands to >= {}", args.len()));
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Err(format!("Invalid number of operands to >= {}", args.len()))`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/builtins.rs:62:9
[INFO] [stderr]    |
[INFO] [stderr] 62 |         return Ok(Atom::Bool(arg1 >= arg2));
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Ok(Atom::Bool(arg1 >= arg2))`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/builtins.rs:68:9
[INFO] [stderr]    |
[INFO] [stderr] 68 |         return Err(format!("Invalid number of operands to <= {}", args.len()));
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Err(format!("Invalid number of operands to <= {}", args.len()))`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/builtins.rs:72:9
[INFO] [stderr]    |
[INFO] [stderr] 72 |         return Ok(Atom::Bool(arg1 <= arg2));
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Ok(Atom::Bool(arg1 <= arg2))`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/builtins.rs:78:9
[INFO] [stderr]    |
[INFO] [stderr] 78 |         return Err(format!("Invalid number of operands to = {}", args.len()));
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Err(format!("Invalid number of operands to = {}", args.len()))`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/builtins.rs:82:9
[INFO] [stderr]    |
[INFO] [stderr] 82 |         return Ok(Atom::Bool(arg1 == arg2));
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Ok(Atom::Bool(arg1 == arg2))`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/builtins.rs:88:9
[INFO] [stderr]    |
[INFO] [stderr] 88 |         return Err(format!("Invalid number of operands to abs {}", args.len()));
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Err(format!("Invalid number of operands to abs {}", args.len()))`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/builtins.rs:91:9
[INFO] [stderr]    |
[INFO] [stderr] 91 |         return Ok(Atom::Int(arg.abs()));
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Ok(Atom::Int(arg.abs()))`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/builtins.rs:101:5
[INFO] [stderr]     |
[INFO] [stderr] 101 |     return Ok(Atom::List(l1))
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Ok(Atom::List(l1))`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/builtins.rs:123:5
[INFO] [stderr]     |
[INFO] [stderr] 123 |     return evaluate(iter.last().unwrap_or(Atom::Nil), env)
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `evaluate(iter.last().unwrap_or(Atom::Nil), env)`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/builtins.rs:131:33
[INFO] [stderr]     |
[INFO] [stderr] 131 |         Atom::Cons(car, cdr) => return Ok(*car),
[INFO] [stderr]     |                                 ^^^^^^^^^^^^^^^ help: remove `return` as shown: `Ok(*car)`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/builtins.rs:134:17
[INFO] [stderr]     |
[INFO] [stderr] 134 |                 return Ok(atoms[0].clone())
[INFO] [stderr]     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Ok(atoms[0].clone())`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/builtins.rs:136:17
[INFO] [stderr]     |
[INFO] [stderr] 136 |                 return Err("CAR expects a pair".to_string())
[INFO] [stderr]     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Err("CAR expects a pair".to_string())`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/builtins.rs:139:14
[INFO] [stderr]     |
[INFO] [stderr] 139 |         _ => return Err("CAR expects a pair".to_string())
[INFO] [stderr]     |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Err("CAR expects a pair".to_string())`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/builtins.rs:148:33
[INFO] [stderr]     |
[INFO] [stderr] 148 |         Atom::Cons(car, cdr) => return Ok(*cdr),
[INFO] [stderr]     |                                 ^^^^^^^^^^^^^^^ help: remove `return` as shown: `Ok(*cdr)`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/builtins.rs:151:17
[INFO] [stderr]     |
[INFO] [stderr] 151 |                 return Ok(Atom::List(atoms.into_iter().skip(1).collect()))
[INFO] [stderr]     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Ok(Atom::List(atoms.into_iter().skip(1).collect()))`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/builtins.rs:153:17
[INFO] [stderr]     |
[INFO] [stderr] 153 |                 return Err("CDR expects a pair".to_string())
[INFO] [stderr]     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Err("CDR expects a pair".to_string())`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/builtins.rs:156:14
[INFO] [stderr]     |
[INFO] [stderr] 156 |         _ => return Err("CDR expects a pair".to_string())
[INFO] [stderr]     |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Err("CDR expects a pair".to_string())`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/builtins.rs:162:9
[INFO] [stderr]     |
[INFO] [stderr] 162 |         return Err(format!("Invalid number of operands to cons {}", args.len()))
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Err(format!("Invalid number of operands to cons {}", args.len()))`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/builtins.rs:164:9
[INFO] [stderr]     |
[INFO] [stderr] 164 |         return Ok(Atom::Cons(Box::new(args[0].clone()), Box::new(args[1].clone())))
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Ok(Atom::Cons(Box::new(args[0].clone()), Box::new(args[1].clone())))`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/builtins.rs:171:9
[INFO] [stderr]     |
[INFO] [stderr] 171 |         return Err(format!("Invalid number of operands to eq? {}", args.len()))
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Err(format!("Invalid number of operands to eq? {}", args.len()))`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/builtins.rs:173:9
[INFO] [stderr]     |
[INFO] [stderr] 173 | /         return Ok(Atom::Bool(match &args[0] {
[INFO] [stderr] 174 | |             &Atom::Bool(_) => args[0] == args[1],
[INFO] [stderr] 175 | |             &Atom::Int(_) => args[0] == args[1],
[INFO] [stderr] 176 | |             _ => &args[0] as *const Atom == &args[1] as *const Atom
[INFO] [stderr] 177 | |         }))
[INFO] [stderr]     | |___________^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] help: remove `return` as shown
[INFO] [stderr]     |
[INFO] [stderr] 173 |         Ok(Atom::Bool(match &args[0] {
[INFO] [stderr] 174 |             &Atom::Bool(_) => args[0] == args[1],
[INFO] [stderr] 175 |             &Atom::Int(_) => args[0] == args[1],
[INFO] [stderr] 176 |             _ => &args[0] as *const Atom == &args[1] as *const Atom
[INFO] [stderr] 177 |         }))
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/builtins.rs:183:9
[INFO] [stderr]     |
[INFO] [stderr] 183 |         return Err(format!("Invalid number of operands to equal? {}", args.len()))
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Err(format!("Invalid number of operands to equal? {}", args.len()))`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/builtins.rs:185:9
[INFO] [stderr]     |
[INFO] [stderr] 185 |         return Ok(Atom::Bool(args[0] == args[1]))
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Ok(Atom::Bool(args[0] == args[1]))`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/builtins.rs:195:9
[INFO] [stderr]     |
[INFO] [stderr] 195 |         return Err(format!("Invalid number of operands to equal? {}", args.len()))
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Err(format!("Invalid number of operands to equal? {}", args.len()))`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: this `else { if .. }` block can be collapsed
[INFO] [stderr]    --> src/builtins.rs:196:12
[INFO] [stderr]     |
[INFO] [stderr] 196 |       } else {
[INFO] [stderr]     |  ____________^
[INFO] [stderr] 197 | |         if let Some(_) = args[0].as_list() {
[INFO] [stderr] 198 | |             return Ok(Atom::Bool(true))
[INFO] [stderr] 199 | |         } else {
[INFO] [stderr] 200 | |             return Ok(Atom::Bool(false))
[INFO] [stderr] 201 | |         }
[INFO] [stderr] 202 | |     }
[INFO] [stderr]     | |_____^
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(clippy::collapsible_if)] on by default
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#collapsible_if
[INFO] [stderr] help: try
[INFO] [stderr]     |
[INFO] [stderr] 196 |     } else if let Some(_) = args[0].as_list() {
[INFO] [stderr] 197 |     return Ok(Atom::Bool(true))
[INFO] [stderr] 198 | } else {
[INFO] [stderr] 199 |     return Ok(Atom::Bool(false))
[INFO] [stderr] 200 | }
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: this `else { if .. }` block can be collapsed
[INFO] [stderr]   --> src/interpreter.rs:88:16
[INFO] [stderr]    |
[INFO] [stderr] 88 |           } else {
[INFO] [stderr]    |  ________________^
[INFO] [stderr] 89 | |             if body.len() == 2 {
[INFO] [stderr] 90 | |                 evaluate(body[1].clone(), env)
[INFO] [stderr] 91 | |             } else {
[INFO] [stderr] 92 | |                 Err("Too many arguments to 'if'".to_string())
[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#collapsible_if
[INFO] [stderr] help: try
[INFO] [stderr]    |
[INFO] [stderr] 88 |         } else if body.len() == 2 {
[INFO] [stderr] 89 |     evaluate(body[1].clone(), env)
[INFO] [stderr] 90 | } else {
[INFO] [stderr] 91 |     Err("Too many arguments to 'if'".to_string())
[INFO] [stderr] 92 | }
[INFO] [stderr]    |
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/interpreter.rs:118:5
[INFO] [stderr]     |
[INFO] [stderr] 118 |     return Ok(None)
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^ help: remove `return` as shown: `Ok(None)`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]   --> src/atom.rs:48:9
[INFO] [stderr]    |
[INFO] [stderr] 48 |         return None
[INFO] [stderr]    |         ^^^^^^^^^^^ help: remove `return` as shown: `None`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/parse.rs:29:14
[INFO] [stderr]    |
[INFO] [stderr] 29 | fn read_list(mut tokens: &mut Vec<String>) -> Result<Vec<Atom>, String> {
[INFO] [stderr]    |              ----^^^^^^
[INFO] [stderr]    |              |
[INFO] [stderr]    |              help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_mut)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/parse.rs:43:25
[INFO] [stderr]    |
[INFO] [stderr] 43 | pub fn read_from_tokens(mut tokens: &mut Vec<String>) -> Result<Atom, String> {
[INFO] [stderr]    |                         ----^^^^^^
[INFO] [stderr]    |                         |
[INFO] [stderr]    |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]   --> src/environment.rs:28:9
[INFO] [stderr]    |
[INFO] [stderr] 28 | /         match self {
[INFO] [stderr] 29 | |             &SchemeFnWrap::Fn(func) => SchemeFnWrap::Fn(func),
[INFO] [stderr] 30 | |             &SchemeFnWrap::Lambda(ref lambda) => SchemeFnWrap::Lambda(lambda.clone())
[INFO] [stderr] 31 | |         }
[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] 28 |         match *self {
[INFO] [stderr] 29 |             SchemeFnWrap::Fn(func) => SchemeFnWrap::Fn(func),
[INFO] [stderr] 30 |             SchemeFnWrap::Lambda(ref lambda) => SchemeFnWrap::Lambda(lambda.clone())
[INFO] [stderr]    |
[INFO] [stderr] 
[INFO] [stderr] warning: the variable `i` is used as a loop counter. Consider using `for (i, item) in self.arg_list.into_iter().enumerate()` or similar iterators
[INFO] [stderr]   --> src/environment.rs:54:21
[INFO] [stderr]    |
[INFO] [stderr] 54 |         for name in self.arg_list.into_iter() {
[INFO] [stderr]    |                     ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::explicit_counter_loop)] on by default
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#explicit_counter_loop
[INFO] [stderr] 
[INFO] [stderr] warning: writing `&String` instead of `&str` involves a new object where a slice will do.
[INFO] [stderr]   --> src/environment.rs:73:51
[INFO] [stderr]    |
[INFO] [stderr] 73 | pub fn env_get(env: &Rc<RefCell<Environment>>, s: &String) -> Result<Atom, String>  {
[INFO] [stderr]    |                                                   ^^^^^^^ help: change this to: `&str`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::ptr_arg)] on by default
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#ptr_arg
[INFO] [stderr] 
[INFO] [stderr] warning: you should consider deriving a `Default` implementation for `environment::Environment`
[INFO] [stderr]   --> src/environment.rs:86:5
[INFO] [stderr]    |
[INFO] [stderr] 86 | /     pub fn new() -> Environment {
[INFO] [stderr] 87 | |         Environment { parent: None, definitions: HashMap::new() }
[INFO] [stderr] 88 | |     }
[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] 67 | #[derive(Default)]
[INFO] [stderr]    |
[INFO] [stderr] 
[INFO] [stderr] warning: writing `&String` instead of `&str` involves a new object where a slice will do.
[INFO] [stderr]    --> src/environment.rs:120:38
[INFO] [stderr]     |
[INFO] [stderr] 120 |     pub fn get_symbol(&self, symbol: &String) -> Result<Atom, String> {
[INFO] [stderr]     |                                      ^^^^^^^ help: change this to: `&str`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#ptr_arg
[INFO] [stderr] 
[INFO] [stderr] warning: this `.fold` can be written more succinctly using another method
[INFO] [stderr]  --> src/builtins.rs:9:63
[INFO] [stderr]   |
[INFO] [stderr] 9 |     return Ok(Atom::Int(args.iter().filter_map(|a| a.as_int()).fold(0, |a, b| a + b)));
[INFO] [stderr]   |                                                               ^^^^^^^^^^^^^^^^^^^^^^ help: try: `.sum()`
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(clippy::unnecessary_fold)] on by default
[INFO] [stderr]   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_fold
[INFO] [stderr] 
[INFO] [stderr] warning: this `.fold` can be written more succinctly using another method
[INFO] [stderr]   --> src/builtins.rs:13:63
[INFO] [stderr]    |
[INFO] [stderr] 13 |     return Ok(Atom::Int(args.iter().filter_map(|a| a.as_int()).fold(1, |a, b| a * b)));
[INFO] [stderr]    |                                                               ^^^^^^^^^^^^^^^^^^^^^^ help: try: `.product()`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_fold
[INFO] [stderr] 
[INFO] [stderr] warning: length comparison to zero
[INFO] [stderr]    --> src/builtins.rs:115:8
[INFO] [stderr]     |
[INFO] [stderr] 115 |     if args.len() == 0 {
[INFO] [stderr]     |        ^^^^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `args.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: length comparison to zero
[INFO] [stderr]    --> src/builtins.rs:133:16
[INFO] [stderr]     |
[INFO] [stderr] 133 |             if atoms.len() > 0 {
[INFO] [stderr]     |                ^^^^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `!atoms.is_empty()`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#len_zero
[INFO] [stderr] 
[INFO] [stderr] warning: length comparison to zero
[INFO] [stderr]    --> src/builtins.rs:150:16
[INFO] [stderr]     |
[INFO] [stderr] 150 |             if atoms.len() > 0 {
[INFO] [stderr]     |                ^^^^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `!atoms.is_empty()`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#len_zero
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to both the expression and the patterns
[INFO] [stderr]    --> src/builtins.rs:173:30
[INFO] [stderr]     |
[INFO] [stderr] 173 |           return Ok(Atom::Bool(match &args[0] {
[INFO] [stderr]     |  ______________________________^
[INFO] [stderr] 174 | |             &Atom::Bool(_) => args[0] == args[1],
[INFO] [stderr] 175 | |             &Atom::Int(_) => args[0] == args[1],
[INFO] [stderr] 176 | |             _ => &args[0] as *const Atom == &args[1] as *const Atom
[INFO] [stderr] 177 | |         }))
[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: try
[INFO] [stderr]     |
[INFO] [stderr] 173 |         return Ok(Atom::Bool(match args[0] {
[INFO] [stderr] 174 |             Atom::Bool(_) => args[0] == args[1],
[INFO] [stderr] 175 |             Atom::Int(_) => args[0] == args[1],
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: redundant pattern matching, consider using `is_some()`
[INFO] [stderr]    --> src/builtins.rs:197:16
[INFO] [stderr]     |
[INFO] [stderr] 197 |           if let Some(_) = args[0].as_list() {
[INFO] [stderr]     |  _________-      ^^^^^^^
[INFO] [stderr] 198 | |             return Ok(Atom::Bool(true))
[INFO] [stderr] 199 | |         } else {
[INFO] [stderr] 200 | |             return Ok(Atom::Bool(false))
[INFO] [stderr] 201 | |         }
[INFO] [stderr]     | |_________- help: try this: `if args[0].as_list().is_some()`
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(clippy::redundant_pattern_matching)] on by default
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_pattern_matching
[INFO] [stderr] 
[INFO] [stderr] warning: this lifetime isn't used in the function definition
[INFO] [stderr]   --> src/interpreter.rs:16:17
[INFO] [stderr]    |
[INFO] [stderr] 16 | pub fn evaluate<'a>(atom: Atom, env: Rc<RefCell<Environment>>) -> Result<Atom, String> {
[INFO] [stderr]    |                 ^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::extra_unused_lifetimes)] on by default
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#extra_unused_lifetimes
[INFO] [stderr] 
[INFO] [stderr] warning: use of `ok_or` followed by a function call
[INFO] [stderr]   --> src/interpreter.rs:26:53
[INFO] [stderr]    |
[INFO] [stderr] 26 |             let first: Atom = try!(list_iter.next().ok_or("Ill-formed expression".to_string()));
[INFO] [stderr]    |                                                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `ok_or_else(|| "Ill-formed expression".to_string())`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::or_fun_call)] on by default
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#or_fun_call
[INFO] [stderr] 
[INFO] [stderr] warning: length comparison to zero
[INFO] [stderr]   --> src/interpreter.rs:57:16
[INFO] [stderr]    |
[INFO] [stderr] 57 |             if body.len() == 0 {
[INFO] [stderr]    |                ^^^^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `body.is_empty()`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#len_zero
[INFO] [stderr] 
[INFO] [stderr] warning: use of `ok_or` followed by a function call
[INFO] [stderr]   --> src/interpreter.rs:69:51
[INFO] [stderr]    |
[INFO] [stderr] 69 |             let name_atom = try!(args_iter.next().ok_or("define needs a name".to_string()));
[INFO] [stderr]    |                                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `ok_or_else(|| "define needs a name".to_string())`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#or_fun_call
[INFO] [stderr] 
[INFO] [stderr] warning: use of `ok_or` followed by a function call
[INFO] [stderr]   --> src/interpreter.rs:70:51
[INFO] [stderr]    |
[INFO] [stderr] 70 |             let name = try!(name_atom.as_symbol().ok_or("define name must be a symbol".to_string()));
[INFO] [stderr]    |                                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `ok_or_else(|| "define name must be a symbol".to_string())`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#or_fun_call
[INFO] [stderr] 
[INFO] [stderr] warning: use of `ok_or` followed by a function call
[INFO] [stderr]    --> src/interpreter.rs:106:54
[INFO] [stderr]     |
[INFO] [stderr] 106 |                 let arg_list = try!(args_iter.next().ok_or("define takes 2 arguments".to_string()));
[INFO] [stderr]     |                                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `ok_or_else(|| "define takes 2 arguments".to_string())`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#or_fun_call
[INFO] [stderr] 
[INFO] [stderr] warning: use of `ok_or` followed by a function call
[INFO] [stderr]    --> src/interpreter.rs:111:55
[INFO] [stderr]     |
[INFO] [stderr] 111 |                 let condition = try!(args_iter.next().ok_or("if requires at least 2 arguments".to_string()));
[INFO] [stderr]     |                                                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `ok_or_else(|| "if requires at least 2 arguments".to_string())`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#or_fun_call
[INFO] [stderr] 
[INFO] [stderr] warning: identical conversion
[INFO] [stderr]   --> src/parse.rs:16:29
[INFO] [stderr]    |
[INFO] [stderr] 16 |       let toks: Vec<String> = input.replace("(", "( ").replace(")", " )")
[INFO] [stderr]    |  _____________________________^
[INFO] [stderr] 17 | |         .replace("'", "' ").split_whitespace().into_iter()
[INFO] [stderr]    | |__________________________________________________________^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::identity_conversion)] on by default
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#identity_conversion
[INFO] [stderr] help: consider removing `.into_iter()`
[INFO] [stderr]    |
[INFO] [stderr] 16 |     let toks: Vec<String> = input.replace("(", "( ").replace(")", " )")
[INFO] [stderr] 17 |         .replace("'", "' ").split_whitespace()
[INFO] [stderr]    |
[INFO] [stderr] 
[INFO] [stderr] warning: length comparison to zero
[INFO] [stderr]   --> src/parse.rs:34:12
[INFO] [stderr]    |
[INFO] [stderr] 34 |         if tokens.len() == 0 {
[INFO] [stderr]    |            ^^^^^^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `tokens.is_empty()`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#len_zero
[INFO] [stderr] 
[INFO] [stderr] warning: length comparison to zero
[INFO] [stderr]   --> src/parse.rs:44:8
[INFO] [stderr]    |
[INFO] [stderr] 44 |     if tokens.len() == 0 {
[INFO] [stderr]    |        ^^^^^^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `tokens.is_empty()`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#len_zero
[INFO] [stderr] 
[INFO] [stderr] warning: use of `ok_or` followed by a function call
[INFO] [stderr]   --> src/atom.rs:25:23
[INFO] [stderr]    |
[INFO] [stderr] 25 |         self.as_int().ok_or("Not an int".to_string())
[INFO] [stderr]    |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `ok_or_else(|| "Not an int".to_string())`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#or_fun_call
[INFO] [stderr] 
[INFO] [stderr] warning: use of `ok_or` followed by a function call
[INFO] [stderr]   --> src/atom.rs:35:24
[INFO] [stderr]    |
[INFO] [stderr] 35 |         self.as_list().ok_or("Not a list".to_string())
[INFO] [stderr]    |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `ok_or_else(|| "Not a list".to_string())`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#or_fun_call
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]   --> src/atom.rs:38:9
[INFO] [stderr]    |
[INFO] [stderr] 38 | /         if let &Atom::Callable(ref callable) = self {
[INFO] [stderr] 39 | |             return Ok(callable)
[INFO] [stderr] 40 | |         } else {
[INFO] [stderr] 41 | |             return Err("Not a callable".to_string())
[INFO] [stderr] 42 | |         }
[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] 38 |         if let Atom::Callable(ref callable) = *self {
[INFO] [stderr]    |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^   ^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]   --> src/atom.rs:45:9
[INFO] [stderr]    |
[INFO] [stderr] 45 | /         if let &Atom::Symbol(ref sym) = self {
[INFO] [stderr] 46 | |             return Some(sym)
[INFO] [stderr] 47 | |         }
[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] 45 |         if let Atom::Symbol(ref sym) = *self {
[INFO] [stderr]    |                ^^^^^^^^^^^^^^^^^^^^^   ^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: use of `ok_or` followed by a function call
[INFO] [stderr]   --> src/atom.rs:51:26
[INFO] [stderr]    |
[INFO] [stderr] 51 |         self.as_symbol().ok_or("Not a symbol".to_string())
[INFO] [stderr]    |                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `ok_or_else(|| "Not a symbol".to_string())`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#or_fun_call
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]   --> src/atom.rs:58:9
[INFO] [stderr]    |
[INFO] [stderr] 58 | /         match self {
[INFO] [stderr] 59 | |             &Bool(b) => write!(f, "'{}'", b),
[INFO] [stderr] 60 | |             &Int(n) => write!(f, "'{}'", n),
[INFO] [stderr] 61 | |             &Symbol(ref s) => write!(f, "'{}'", &**s),
[INFO] [stderr] ...  |
[INFO] [stderr] 65 | |             &Nil => write!(f, "Nil"),
[INFO] [stderr] 66 | |         }
[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] 58 |         match *self {
[INFO] [stderr] 59 |             Bool(b) => write!(f, "'{}'", b),
[INFO] [stderr] 60 |             Int(n) => write!(f, "'{}'", n),
[INFO] [stderr] 61 |             Symbol(ref s) => write!(f, "'{}'", &**s),
[INFO] [stderr] 62 |             Cons(ref car, ref cdr) => write!(f, "'({:?} . {:?})", &**car, &**cdr),
[INFO] [stderr] 63 |             List(ref atoms) => write!(f, "{:?}", &**atoms),
[INFO] [stderr]  ...
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]   --> src/atom.rs:74:9
[INFO] [stderr]    |
[INFO] [stderr] 74 | /         match self {
[INFO] [stderr] 75 | |             &Bool(b) => write!(f, "{}", b),
[INFO] [stderr] 76 | |             &Int(n) => write!(f, "{}", n),
[INFO] [stderr] 77 | |             &Symbol(ref s) => write!(f, "{}", &**s),
[INFO] [stderr] ...  |
[INFO] [stderr] 91 | |             &Nil => write!(f, "Nil"),
[INFO] [stderr] 92 | |         }
[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] 74 |         match *self {
[INFO] [stderr] 75 |             Bool(b) => write!(f, "{}", b),
[INFO] [stderr] 76 |             Int(n) => write!(f, "{}", n),
[INFO] [stderr] 77 |             Symbol(ref s) => write!(f, "{}", &**s),
[INFO] [stderr] 78 |             Cons(ref car, ref cdr) => write!(f, "'({} . {})", &**car, &**cdr),
[INFO] [stderr] 79 |             List(ref atoms) => {
[INFO] [stderr]  ...
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/parse.rs:29:14
[INFO] [stderr]    |
[INFO] [stderr] 29 | fn read_list(mut tokens: &mut Vec<String>) -> Result<Vec<Atom>, String> {
[INFO] [stderr]    |              ----^^^^^^
[INFO] [stderr]    |              |
[INFO] [stderr]    |              help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_mut)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/parse.rs:43:25
[INFO] [stderr]    |
[INFO] [stderr] 43 | pub fn read_from_tokens(mut tokens: &mut Vec<String>) -> Result<Atom, String> {
[INFO] [stderr]    |                         ----^^^^^^
[INFO] [stderr]    |                         |
[INFO] [stderr]    |                         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]   --> src/environment.rs:28:9
[INFO] [stderr]    |
[INFO] [stderr] 28 | /         match self {
[INFO] [stderr] 29 | |             &SchemeFnWrap::Fn(func) => SchemeFnWrap::Fn(func),
[INFO] [stderr] 30 | |             &SchemeFnWrap::Lambda(ref lambda) => SchemeFnWrap::Lambda(lambda.clone())
[INFO] [stderr] 31 | |         }
[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] 28 |         match *self {
[INFO] [stderr] 29 |             SchemeFnWrap::Fn(func) => SchemeFnWrap::Fn(func),
[INFO] [stderr] 30 |             SchemeFnWrap::Lambda(ref lambda) => SchemeFnWrap::Lambda(lambda.clone())
[INFO] [stderr]    |
[INFO] [stderr] 
[INFO] [stderr] warning: the variable `i` is used as a loop counter. Consider using `for (i, item) in self.arg_list.into_iter().enumerate()` or similar iterators
[INFO] [stderr]   --> src/environment.rs:54:21
[INFO] [stderr]    |
[INFO] [stderr] 54 |         for name in self.arg_list.into_iter() {
[INFO] [stderr]    |                     ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::explicit_counter_loop)] on by default
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#explicit_counter_loop
[INFO] [stderr] 
[INFO] [stderr] warning: writing `&String` instead of `&str` involves a new object where a slice will do.
[INFO] [stderr]   --> src/environment.rs:73:51
[INFO] [stderr]    |
[INFO] [stderr] 73 | pub fn env_get(env: &Rc<RefCell<Environment>>, s: &String) -> Result<Atom, String>  {
[INFO] [stderr]    |                                                   ^^^^^^^ help: change this to: `&str`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::ptr_arg)] on by default
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#ptr_arg
[INFO] [stderr] 
[INFO] [stderr] warning: you should consider deriving a `Default` implementation for `environment::Environment`
[INFO] [stderr]   --> src/environment.rs:86:5
[INFO] [stderr]    |
[INFO] [stderr] 86 | /     pub fn new() -> Environment {
[INFO] [stderr] 87 | |         Environment { parent: None, definitions: HashMap::new() }
[INFO] [stderr] 88 | |     }
[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] 67 | #[derive(Default)]
[INFO] [stderr]    |
[INFO] [stderr] 
[INFO] [stderr] warning: writing `&String` instead of `&str` involves a new object where a slice will do.
[INFO] [stderr]    --> src/environment.rs:120:38
[INFO] [stderr]     |
[INFO] [stderr] 120 |     pub fn get_symbol(&self, symbol: &String) -> Result<Atom, String> {
[INFO] [stderr]     |                                      ^^^^^^^ help: change this to: `&str`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#ptr_arg
[INFO] [stderr] 
[INFO] [stderr] warning: this `.fold` can be written more succinctly using another method
[INFO] [stderr]  --> src/builtins.rs:9:63
[INFO] [stderr]   |
[INFO] [stderr] 9 |     return Ok(Atom::Int(args.iter().filter_map(|a| a.as_int()).fold(0, |a, b| a + b)));
[INFO] [stderr]   |                                                               ^^^^^^^^^^^^^^^^^^^^^^ help: try: `.sum()`
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(clippy::unnecessary_fold)] on by default
[INFO] [stderr]   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_fold
[INFO] [stderr] 
[INFO] [stderr] warning: this `.fold` can be written more succinctly using another method
[INFO] [stderr]   --> src/builtins.rs:13:63
[INFO] [stderr]    |
[INFO] [stderr] 13 |     return Ok(Atom::Int(args.iter().filter_map(|a| a.as_int()).fold(1, |a, b| a * b)));
[INFO] [stderr]    |                                                               ^^^^^^^^^^^^^^^^^^^^^^ help: try: `.product()`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_fold
[INFO] [stderr] 
[INFO] [stderr] warning: length comparison to zero
[INFO] [stderr]    --> src/builtins.rs:115:8
[INFO] [stderr]     |
[INFO] [stderr] 115 |     if args.len() == 0 {
[INFO] [stderr]     |        ^^^^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `args.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: length comparison to zero
[INFO] [stderr]    --> src/builtins.rs:133:16
[INFO] [stderr]     |
[INFO] [stderr] 133 |             if atoms.len() > 0 {
[INFO] [stderr]     |                ^^^^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `!atoms.is_empty()`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#len_zero
[INFO] [stderr] 
[INFO] [stderr] warning: length comparison to zero
[INFO] [stderr]    --> src/builtins.rs:150:16
[INFO] [stderr]     |
[INFO] [stderr] 150 |             if atoms.len() > 0 {
[INFO] [stderr]     |                ^^^^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `!atoms.is_empty()`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#len_zero
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to both the expression and the patterns
[INFO] [stderr]    --> src/builtins.rs:173:30
[INFO] [stderr]     |
[INFO] [stderr] 173 |           return Ok(Atom::Bool(match &args[0] {
[INFO] [stderr]     |  ______________________________^
[INFO] [stderr] 174 | |             &Atom::Bool(_) => args[0] == args[1],
[INFO] [stderr] 175 | |             &Atom::Int(_) => args[0] == args[1],
[INFO] [stderr] 176 | |             _ => &args[0] as *const Atom == &args[1] as *const Atom
[INFO] [stderr] 177 | |         }))
[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: try
[INFO] [stderr]     |
[INFO] [stderr] 173 |         return Ok(Atom::Bool(match args[0] {
[INFO] [stderr] 174 |             Atom::Bool(_) => args[0] == args[1],
[INFO] [stderr] 175 |             Atom::Int(_) => args[0] == args[1],
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: redundant pattern matching, consider using `is_some()`
[INFO] [stderr]    --> src/builtins.rs:197:16
[INFO] [stderr]     |
[INFO] [stderr] 197 |           if let Some(_) = args[0].as_list() {
[INFO] [stderr]     |  _________-      ^^^^^^^
[INFO] [stderr] 198 | |             return Ok(Atom::Bool(true))
[INFO] [stderr] 199 | |         } else {
[INFO] [stderr] 200 | |             return Ok(Atom::Bool(false))
[INFO] [stderr] 201 | |         }
[INFO] [stderr]     | |_________- help: try this: `if args[0].as_list().is_some()`
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(clippy::redundant_pattern_matching)] on by default
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_pattern_matching
[INFO] [stderr] 
[INFO] [stderr] warning: this lifetime isn't used in the function definition
[INFO] [stderr]   --> src/interpreter.rs:16:17
[INFO] [stderr]    |
[INFO] [stderr] 16 | pub fn evaluate<'a>(atom: Atom, env: Rc<RefCell<Environment>>) -> Result<Atom, String> {
[INFO] [stderr]    |                 ^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::extra_unused_lifetimes)] on by default
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#extra_unused_lifetimes
[INFO] [stderr] 
[INFO] [stderr] warning: use of `ok_or` followed by a function call
[INFO] [stderr]   --> src/interpreter.rs:26:53
[INFO] [stderr]    |
[INFO] [stderr] 26 |             let first: Atom = try!(list_iter.next().ok_or("Ill-formed expression".to_string()));
[INFO] [stderr]    |                                                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `ok_or_else(|| "Ill-formed expression".to_string())`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::or_fun_call)] on by default
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#or_fun_call
[INFO] [stderr] 
[INFO] [stderr] warning: length comparison to zero
[INFO] [stderr]   --> src/interpreter.rs:57:16
[INFO] [stderr]    |
[INFO] [stderr] 57 |             if body.len() == 0 {
[INFO] [stderr]    |                ^^^^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `body.is_empty()`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#len_zero
[INFO] [stderr] 
[INFO] [stderr] warning: use of `ok_or` followed by a function call
[INFO] [stderr]   --> src/interpreter.rs:69:51
[INFO] [stderr]    |
[INFO] [stderr] 69 |             let name_atom = try!(args_iter.next().ok_or("define needs a name".to_string()));
[INFO] [stderr]    |                                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `ok_or_else(|| "define needs a name".to_string())`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#or_fun_call
[INFO] [stderr] 
[INFO] [stderr] warning: use of `ok_or` followed by a function call
[INFO] [stderr]   --> src/interpreter.rs:70:51
[INFO] [stderr]    |
[INFO] [stderr] 70 |             let name = try!(name_atom.as_symbol().ok_or("define name must be a symbol".to_string()));
[INFO] [stderr]    |                                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `ok_or_else(|| "define name must be a symbol".to_string())`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#or_fun_call
[INFO] [stderr] 
[INFO] [stderr] warning: use of `ok_or` followed by a function call
[INFO] [stderr]    --> src/interpreter.rs:106:54
[INFO] [stderr]     |
[INFO] [stderr] 106 |                 let arg_list = try!(args_iter.next().ok_or("define takes 2 arguments".to_string()));
[INFO] [stderr]     |                                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `ok_or_else(|| "define takes 2 arguments".to_string())`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#or_fun_call
[INFO] [stderr] 
[INFO] [stderr] warning: use of `ok_or` followed by a function call
[INFO] [stderr]    --> src/interpreter.rs:111:55
[INFO] [stderr]     |
[INFO] [stderr] 111 |                 let condition = try!(args_iter.next().ok_or("if requires at least 2 arguments".to_string()));
[INFO] [stderr]     |                                                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `ok_or_else(|| "if requires at least 2 arguments".to_string())`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#or_fun_call
[INFO] [stderr] 
[INFO] [stderr] warning: identical conversion
[INFO] [stderr]   --> src/parse.rs:16:29
[INFO] [stderr]    |
[INFO] [stderr] 16 |       let toks: Vec<String> = input.replace("(", "( ").replace(")", " )")
[INFO] [stderr]    |  _____________________________^
[INFO] [stderr] 17 | |         .replace("'", "' ").split_whitespace().into_iter()
[INFO] [stderr]    | |__________________________________________________________^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::identity_conversion)] on by default
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#identity_conversion
[INFO] [stderr] help: consider removing `.into_iter()`
[INFO] [stderr]    |
[INFO] [stderr] 16 |     let toks: Vec<String> = input.replace("(", "( ").replace(")", " )")
[INFO] [stderr] 17 |         .replace("'", "' ").split_whitespace()
[INFO] [stderr]    |
[INFO] [stderr] 
[INFO] [stderr] warning: length comparison to zero
[INFO] [stderr]   --> src/parse.rs:34:12
[INFO] [stderr]    |
[INFO] [stderr] 34 |         if tokens.len() == 0 {
[INFO] [stderr]    |            ^^^^^^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `tokens.is_empty()`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#len_zero
[INFO] [stderr] 
[INFO] [stderr] warning: length comparison to zero
[INFO] [stderr]   --> src/parse.rs:44:8
[INFO] [stderr]    |
[INFO] [stderr] 44 |     if tokens.len() == 0 {
[INFO] [stderr]    |        ^^^^^^^^^^^^^^^^^ help: using `is_empty` is clearer and more explicit: `tokens.is_empty()`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#len_zero
[INFO] [stderr] 
[INFO] [stderr] warning: use of `ok_or` followed by a function call
[INFO] [stderr]   --> src/atom.rs:25:23
[INFO] [stderr]    |
[INFO] [stderr] 25 |         self.as_int().ok_or("Not an int".to_string())
[INFO] [stderr]    |                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `ok_or_else(|| "Not an int".to_string())`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#or_fun_call
[INFO] [stderr] 
[INFO] [stderr] warning: use of `ok_or` followed by a function call
[INFO] [stderr]   --> src/atom.rs:35:24
[INFO] [stderr]    |
[INFO] [stderr] 35 |         self.as_list().ok_or("Not a list".to_string())
[INFO] [stderr]    |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `ok_or_else(|| "Not a list".to_string())`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#or_fun_call
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]   --> src/atom.rs:38:9
[INFO] [stderr]    |
[INFO] [stderr] 38 | /         if let &Atom::Callable(ref callable) = self {
[INFO] [stderr] 39 | |             return Ok(callable)
[INFO] [stderr] 40 | |         } else {
[INFO] [stderr] 41 | |             return Err("Not a callable".to_string())
[INFO] [stderr] 42 | |         }
[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] 38 |         if let Atom::Callable(ref callable) = *self {
[INFO] [stderr]    |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^   ^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]   --> src/atom.rs:45:9
[INFO] [stderr]    |
[INFO] [stderr] 45 | /         if let &Atom::Symbol(ref sym) = self {
[INFO] [stderr] 46 | |             return Some(sym)
[INFO] [stderr] 47 | |         }
[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] 45 |         if let Atom::Symbol(ref sym) = *self {
[INFO] [stderr]    |                ^^^^^^^^^^^^^^^^^^^^^   ^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: use of `ok_or` followed by a function call
[INFO] [stderr]   --> src/atom.rs:51:26
[INFO] [stderr]    |
[INFO] [stderr] 51 |         self.as_symbol().ok_or("Not a symbol".to_string())
[INFO] [stderr]    |                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `ok_or_else(|| "Not a symbol".to_string())`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#or_fun_call
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]   --> src/atom.rs:58:9
[INFO] [stderr]    |
[INFO] [stderr] 58 | /         match self {
[INFO] [stderr] 59 | |             &Bool(b) => write!(f, "'{}'", b),
[INFO] [stderr] 60 | |             &Int(n) => write!(f, "'{}'", n),
[INFO] [stderr] 61 | |             &Symbol(ref s) => write!(f, "'{}'", &**s),
[INFO] [stderr] ...  |
[INFO] [stderr] 65 | |             &Nil => write!(f, "Nil"),
[INFO] [stderr] 66 | |         }
[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] 58 |         match *self {
[INFO] [stderr] 59 |             Bool(b) => write!(f, "'{}'", b),
[INFO] [stderr] 60 |             Int(n) => write!(f, "'{}'", n),
[INFO] [stderr] 61 |             Symbol(ref s) => write!(f, "'{}'", &**s),
[INFO] [stderr] 62 |             Cons(ref car, ref cdr) => write!(f, "'({:?} . {:?})", &**car, &**cdr),
[INFO] [stderr] 63 |             List(ref atoms) => write!(f, "{:?}", &**atoms),
[INFO] [stderr]  ...
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]   --> src/atom.rs:74:9
[INFO] [stderr]    |
[INFO] [stderr] 74 | /         match self {
[INFO] [stderr] 75 | |             &Bool(b) => write!(f, "{}", b),
[INFO] [stderr] 76 | |             &Int(n) => write!(f, "{}", n),
[INFO] [stderr] 77 | |             &Symbol(ref s) => write!(f, "{}", &**s),
[INFO] [stderr] ...  |
[INFO] [stderr] 91 | |             &Nil => write!(f, "Nil"),
[INFO] [stderr] 92 | |         }
[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] 74 |         match *self {
[INFO] [stderr] 75 |             Bool(b) => write!(f, "{}", b),
[INFO] [stderr] 76 |             Int(n) => write!(f, "{}", n),
[INFO] [stderr] 77 |             Symbol(ref s) => write!(f, "{}", &**s),
[INFO] [stderr] 78 |             Cons(ref car, ref cdr) => write!(f, "'({} . {})", &**car, &**cdr),
[INFO] [stderr] 79 |             List(ref atoms) => {
[INFO] [stderr]  ...
[INFO] [stderr] 
[INFO] [stderr] warning: Err(_) will match all errors, maybe not a good idea
[INFO] [stderr]  --> tests/lib.rs:7:9
[INFO] [stderr]   |
[INFO] [stderr] 7 |         Err(_) => panic!()
[INFO] [stderr]   |         ^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(clippy::match_wild_err_arm)] on by default
[INFO] [stderr]   = note: to remove this warning, match each error separately or use unreachable macro
[INFO] [stderr]   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_wild_err_arm
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 2.29s
[INFO] running `"docker" "inspect" "f70b4273d45950bf3e59cfdac91a376103c4a07fc217aee3349fc729aad15ab7"`
[INFO] running `"docker" "rm" "-f" "f70b4273d45950bf3e59cfdac91a376103c4a07fc217aee3349fc729aad15ab7"`
[INFO] [stdout] f70b4273d45950bf3e59cfdac91a376103c4a07fc217aee3349fc729aad15ab7