Refactor to use into_group_map from Itertools

Author: phansch

clippy_dev/Cargo.lock

@@ -5,5 +5,6 @@ authors = ["Philipp Hansch <[email protected]>"]
 
 [dependencies]
 clap = "~2.32"
+itertools = "0.7"
 regex = "1"
 lazy_static = "1.0"

clippy_dev/Cargo.toml

@@ -1,8 +1,11 @@
 extern crate regex;
 #[macro_use]
 extern crate lazy_static;
+extern crate itertools;
 
 use regex::Regex;
+use itertools::Itertools;
+use std::collections::HashMap;
 use std::ffi::OsStr;
 use std::fs;
 use std::io::prelude::*;
@@ -47,8 +50,9 @@ impl Lint {
         lints.iter().filter(|l| l.deprecation.is_none()).cloned().collect::<Vec<Lint>>()
     }
 
-    pub fn in_lint_group(group: &str, lints: &[Lint]) -> Vec<Lint> {
-        lints.iter().filter(|l| l.group == group).cloned().collect::<Vec<Lint>>()
+    /// Returns the lints in a HashMap, grouped by the different lint groups
+    pub fn by_lint_group(lints: &[Lint]) -> HashMap<String, Vec<Lint>> {
+        lints.iter().map(|lint| (lint.group.to_string(), lint.clone())).into_group_map()
     }
 }
 
@@ -141,13 +145,19 @@ fn test_active_lints() {
 }
 
 #[test]
-fn test_in_lint_group() {
+fn test_by_lint_group() {
     let lints = vec![
-        Lint::new("ptr_arg", "style", "really long text", None, "module_name"),
-        Lint::new("doc_markdown", "pedantic", "single line", None, "module_name"),
-    ];
-    let expected = vec![
-        Lint::new("ptr_arg", "style", "really long text", None, "module_name")
+        Lint::new("should_assert_eq", "group1", "abc", None, "module_name"),
+        Lint::new("should_assert_eq2", "group2", "abc", None, "module_name"),
+        Lint::new("incorrect_match", "group1", "abc", None, "module_name"),
     ];
-    assert_eq!(expected, Lint::in_lint_group("style", &lints));
+    let mut expected: HashMap<String, Vec<Lint>> = HashMap::new();
+    expected.insert("group1".to_string(), vec![
+        Lint::new("should_assert_eq", "group1", "abc", None, "module_name"),
+        Lint::new("incorrect_match", "group1", "abc", None, "module_name"),
+    ]);
+    expected.insert("group2".to_string(), vec![
+        Lint::new("should_assert_eq2", "group2", "abc", None, "module_name")
+    ]);
+    assert_eq!(expected, Lint::by_lint_group(&lints));
 }

clippy_dev/src/lib.rs

@@ -28,26 +28,18 @@ fn main() {
 
 fn print_lints() {
     let lint_list = collect_all();
-    let print_clippy_lint_groups: [&str; 7] = [
-        "correctness",
-        "style",
-        "complexity",
-        "perf",
-        "pedantic",
-        "nursery",
-        "restriction"
-    ];
-    // We could use itertools' group_by to make this much more concise:
-    for group in &print_clippy_lint_groups {
-        println!("\n## {}", group);
-
-        let mut group_lints = Lint::in_lint_group(group, &lint_list);
-        group_lints.sort_by(|a, b| a.name.cmp(&b.name));
-
-        for lint in group_lints {
-            if lint.deprecation.is_some() { continue; }
+    let grouped_by_lint_group = Lint::by_lint_group(&lint_list);
+
+    for (lint_group, mut lints) in grouped_by_lint_group {
+        if lint_group == "Deprecated" { continue; }
+        println!("\n## {}", lint_group);
+
+        lints.sort_by(|a, b| a.name.cmp(&b.name));
+
+        for lint in lints {
             println!("* [{}]({}#{}) ({})", lint.name, clippy_dev::DOCS_LINK.clone(), lint.name, lint.desc);
         }
     }
+
     println!("there are {} lints", Lint::active_lints(&lint_list).len());
 }