new to_iter lint, still WIP but should supercede the previous for_each lint

Author: Cameron-Low

Cargo.lock

@@ -14,6 +14,7 @@ publish = false
 crate-type = ["cdylib"]
 
 [dependencies]
+to_iter = { path = "lints/to_iter", features = ["rlib"] }
 for_each = { path = "lints/for_each", features = ["rlib"] }
 filter = { path = "lints/filter", features = ["rlib"] }
 map = { path = "lints/map", features = ["rlib"] }
@@ -32,6 +33,7 @@ rustc_private = true
 [workspace]
 members = [
     "lints/rayon_imports",
+    "lints/to_iter",
     "lints/for_each",
     "lints/filter",
     "lints/map",

Cargo.toml

@@ -478,3 +478,14 @@ fn mut_var_declared_in_closure() {
         .collect();
     println!("{:?}", doubled_numbers);
 }
+
+// should parallelize
+fn return_loop() -> Option<()> {
+    let num_workers = 10;
+    let locals = vec![1, 2, 3, 4, 5];
+    (0..num_workers).into_par_iter().try_for_each(|index| {
+        let item = locals.get(index)?;
+        return Some(());
+    })?;
+    Some(())
+}

lints/par_iter/ui/main.fixed

@@ -478,3 +478,14 @@ fn mut_var_declared_in_closure() {
         .collect();
     println!("{:?}", doubled_numbers);
 }
+
+// should parallelize
+fn return_loop() -> Option<()> {
+    let num_workers = 10;
+    let locals = vec![1, 2, 3, 4, 5];
+    (0..num_workers).into_iter().try_for_each(|index| {
+        let item = locals.get(index)?;
+        return Some(());
+    })?;
+    Some(())
+}

lints/par_iter/ui/main.rs

@@ -123,5 +123,11 @@ LL ~     let doubled_numbers: Vec<i32> = numbers
 LL +         .into_par_iter()
    |
 
-warning: 14 warnings emitted
+warning: found iterator that can be parallelized
+  --> $DIR/main.rs:486:5
+   |
+LL |     (0..num_workers).into_iter().try_for_each(|index| {
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try using a parallel iterator: `(0..num_workers).into_par_iter()`
+
+warning: 15 warnings emitted
 

lints/par_iter/ui/main.stderr

@@ -0,0 +1 @@
+/target

lints/to_iter/.gitignore

@@ -0,0 +1,31 @@
+[package]
+name = "to_iter"
+version = "0.1.0"
+authors = ["authors go here"]
+description = "description goes here"
+edition = "2021"
+publish = false
+
+[lib]
+crate-type = ["cdylib", "rlib"]
+
+[dependencies]
+dylint_linting = "3.0.0"
+
+clippy_utils = { workspace = true }
+utils = { workspace = true }
+[dev-dependencies]
+dylint_testing = "3.0.0"
+
+[package.metadata.rust-analyzer]
+rustc_private = true
+
+[features]
+rlib = ["dylint_linting/constituent"]
+
+[[example]]
+name = "to_iter_main"
+path = "ui/main.rs"
+
+[lints]
+workspace = true

lints/to_iter/Cargo.toml

@@ -0,0 +1,17 @@
+# template
+
+### What it does
+
+### Why is this bad?
+
+### Known problems
+Remove if none.
+
+### Example
+```rust
+// example code where a warning is issued
+```
+Use instead:
+```rust
+// example code that does not raise a warning
+```