Refactoring of collection folding. In the simple case, we can use map/collect so we should. The par_iter lint should be able to parallelize these.

Author: Cameron-Low

Cargo.lock

@@ -1,7 +1,7 @@
 [package]
 name = "mate"
 version = "0.1.0"
-authors = ["Cameron Low <email>", "Luca Carlig <luca.carlig@huawei.com"]
+authors = ["Cameron Low <cameron.low.2018@bristol.ac.uk>", "Luca Carlig <luca.carlig@huawei.com"]
 description = "library of lints for automatic parallelization"
 edition = "2021"
 publish = false
@@ -13,12 +13,12 @@ crate-type = ["cdylib"]
 [dependencies]
 for_each = { path = "lints/for_each", features = ["rlib"] }
 filter = { path = "lints/filter", features = ["rlib"] }
+map = { path = "lints/map", features = ["rlib"] }
 fold = { path = "lints/fold", features = ["rlib"] }
 par_fold = { path = "lints/par_fold", features = ["rlib"] }
 par_iter = { path = "lints/par_iter", features = ["rlib"] }
 rayon_imports = { path = "lints/rayon_imports", features = ["rlib"] }
 
-
 dylint_linting = { version = "2.6.1" }
 
 [package.metadata.rust-analyzer]
@@ -28,6 +28,7 @@ rustc_private = true
 members = [
     "lints/for_each",
     "lints/filter",
+    "lints/map",
     "lints/fold",
     "lints/par_fold",
     "lints/par_iter",

Cargo.toml

@@ -1,6 +1,7 @@
 #![feature(rustc_private)]
 #![warn(unused_extern_crates)]
 #![feature(let_chains)]
+#![feature(iter_intersperse)]
 
 #[cfg(not(feature = "rlib"))]
 dylint_linting::dylint_library!();
@@ -11,17 +12,13 @@ extern crate rustc_lint;
 extern crate rustc_session;
 extern crate rustc_span;
 
-mod hashmap;
 mod simple;
-mod vec;
 
 #[allow(clippy::no_mangle_with_rust_abi)]
 #[cfg_attr(not(feature = "rlib"), no_mangle)]
 
 pub fn register_lints(_sess: &rustc_session::Session, lint_store: &mut rustc_lint::LintStore) {
     lint_store.register_late_pass(|_| Box::new(simple::FoldSimple));
-    lint_store.register_late_pass(|_| Box::new(vec::FoldVec));
-    lint_store.register_late_pass(|_| Box::new(hashmap::FoldHashmap));
 }
 
 #[test]

lints/fold/src/hashmap.rs

@@ -1,8 +1,6 @@
 // run-rustfix
 fn main() {
     warn_fold_simple();
-    warn_fold_vec();
-    warn_fold_hashmap();
     get_upload_file_total_size();
 }
 
@@ -15,24 +13,6 @@ fn warn_fold_simple() {
     println!("Sum: {}", sum);
 }
 
-fn warn_fold_vec() {
-    let mut data = vec![];
-    let numbers = vec![1, 2, 3, 4, 5];
-    data = numbers.iter().fold(data, |mut data, &num| {  data.push(num * 3); data });
-
-    println!("Data: {:?}", data);
-}
-
-fn warn_fold_hashmap() {
-    use std::collections::HashMap;
-
-    let mut data = HashMap::new();
-    let numbers = vec![1, 2, 3, 4, 5];
-    data = numbers.iter().fold(data, |mut data, &num| {  data.insert(num, num.to_string()); data });
-
-    println!("Data: {:?}", data);
-}
-
 fn get_upload_file_total_size() -> u64 {
     let some_num = vec![0; 10];
     let mut file_total_size = 0;

lints/fold/src/lib.rs

@@ -1,8 +1,6 @@
 // run-rustfix
 fn main() {
     warn_fold_simple();
-    warn_fold_vec();
-    warn_fold_hashmap();
     get_upload_file_total_size();
 }
 
@@ -17,28 +15,6 @@ fn warn_fold_simple() {
     println!("Sum: {}", sum);
 }
 
-fn warn_fold_vec() {
-    let mut data = vec![];
-    let numbers = vec![1, 2, 3, 4, 5];
-    numbers.iter().for_each(|&num| {
-        data.push(num * 3);
-    });
-
-    println!("Data: {:?}", data);
-}
-
-fn warn_fold_hashmap() {
-    use std::collections::HashMap;
-
-    let mut data = HashMap::new();
-    let numbers = vec![1, 2, 3, 4, 5];
-    numbers.iter().for_each(|&num| {
-        data.insert(num, num.to_string());
-    });
-
-    println!("Data: {:?}", data);
-}
-
 fn get_upload_file_total_size() -> u64 {
     let some_num = vec![0; 10];
     let mut file_total_size = 0;