[Rust] Anagram

Author: sanderploegsma

rust/Cargo.lock

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+# Generated by Cargo
+# will have compiled files and executables
+/target/
+**/*.rs.bk
+
+# Remove Cargo.lock from gitignore if creating an executable, leave it for libraries
+# More information here http://doc.crates.io/guide.html#cargotoml-vs-cargolock
+Cargo.lock

rust/anagram/.gitignore

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+[package]
+edition = "2018"
+name = "anagram"
+version = "0.0.0"
+
+[dependencies]
+itertools = "0.9.0"

rust/anagram/Cargo.toml

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+# Anagram
+
+An anagram is a rearrangement of letters to form a new word.
+Given a word and a list of candidates, select the sublist of anagrams of the given word.
+
+Given `"listen"` and a list of candidates like `"enlists" "google"
+"inlets" "banana"` the program should return a list containing
+`"inlets"`.
+
+# Hints
+
+The solution is case insensitive, which means `"WOrd"` is the same as `"word"` or `"woRd"`. It may help to take a peek at the [std library](https://doc.rust-lang.org/std/primitive.char.html) for functions that can convert between them.
+
+The solution cannot contain the input word. A word is always an anagram of itself, which means it is not an interesting result. Given `"hello"` and the list `["hello", "olleh"]` the answer is `["olleh"]`.
+
+You are going to have to adjust the function signature provided in the stub in order for the lifetimes to work out properly. This is intentional: what's there demonstrates the basics of lifetime syntax, and what's missing teaches how to interpret lifetime-related compiler errors.
+
+
+## Rust Installation
+
+Refer to the [exercism help page][help-page] for Rust installation and learning
+resources.
+
+## Writing the Code
+
+Execute the tests with:
+
+```bash
+$ cargo test
+```
+
+All but the first test have been ignored. After you get the first test to
+pass, open the tests source file which is located in the `tests` directory
+and remove the `#[ignore]` flag from the next test and get the tests to pass
+again. Each separate test is a function with `#[test]` flag above it.
+Continue, until you pass every test.
+
+If you wish to run all ignored tests without editing the tests source file, use:
+
+```bash
+$ cargo test -- --ignored
+```
+
+To run a specific test, for example `some_test`, you can use:
+
+```bash
+$ cargo test some_test
+```
+
+If the specific test is ignored use:
+
+```bash
+$ cargo test some_test -- --ignored
+```
+
+To learn more about Rust tests refer to the [online test documentation][rust-tests]
+
+Make sure to read the [Modules][modules] chapter if you
+haven't already, it will help you with organizing your files.
+
+## Further improvements
+
+After you have solved the exercise, please consider using the additional utilities, described in the [installation guide](https://exercism.io/tracks/rust/installation), to further refine your final solution.
+
+To format your solution, inside the solution directory use
+
+```bash
+cargo fmt
+```
+
+To see, if your solution contains some common ineffective use cases, inside the solution directory use
+
+```bash
+cargo clippy --all-targets
+```
+
+## Submitting the solution
+
+Generally you should submit all files in which you implemented your solution (`src/lib.rs` in most cases). If you are using any external crates, please consider submitting the `Cargo.toml` file. This will make the review process faster and clearer.
+
+## Feedback, Issues, Pull Requests
+
+The [exercism/rust](https://github.com/exercism/rust) repository on GitHub is the home for all of the Rust exercises. If you have feedback about an exercise, or want to help implement new exercises, head over there and create an issue. Members of the rust track team are happy to help!
+
+If you want to know more about Exercism, take a look at the [contribution guide](https://github.com/exercism/docs/blob/master/contributing-to-language-tracks/README.md).
+
+[help-page]: https://exercism.io/tracks/rust/learning
+[modules]: https://doc.rust-lang.org/book/ch07-02-defining-modules-to-control-scope-and-privacy.html
+[cargo]: https://doc.rust-lang.org/book/ch14-00-more-about-cargo.html
+[rust-tests]: https://doc.rust-lang.org/book/ch11-02-running-tests.html
+
+## Source
+
+Inspired by the Extreme Startup game [https://github.com/rchatley/extreme_startup](https://github.com/rchatley/extreme_startup)
+
+## Submitting Incomplete Solutions
+It's possible to submit an incomplete solution so you can see how others have completed the exercise.

rust/anagram/README.md

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+use std::collections::HashSet;
+use itertools::Itertools;
+
+fn is_anagram(a: String, b: String) -> bool {
+    a != b && a.chars().sorted().collect::<String>() == b.chars().sorted().collect::<String>()
+}
+
+pub fn anagrams_for<'a>(word: &str, possible_anagrams: &'a [&str]) -> HashSet<&'a str> {
+    possible_anagrams
+        .iter()
+        .copied()
+        .filter(|&w| is_anagram(w.to_lowercase(), word.to_lowercase()))
+        .collect()
+}

rust/anagram/src/lib.rs

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+use std::collections::HashSet;
+use std::iter::FromIterator;
+
+fn process_anagram_case(word: &str, inputs: &[&str], expected: &[&str]) {
+    let result = anagram::anagrams_for(word, inputs);
+
+    let expected: HashSet<&str> = HashSet::from_iter(expected.iter().cloned());
+
+    assert_eq!(result, expected);
+}
+
+#[test]
+fn test_no_matches() {
+    let word = "diaper";
+
+    let inputs = ["hello", "world", "zombies", "pants"];
+
+    let outputs = vec![];
+
+    process_anagram_case(word, &inputs, &outputs);
+}
+
+#[test]
+fn test_detect_simple_anagram() {
+    let word = "ant";
+
+    let inputs = ["tan", "stand", "at"];
+
+    let outputs = vec!["tan"];
+
+    process_anagram_case(word, &inputs, &outputs);
+}
+
+#[test]
+fn test_does_not_confuse_different_duplicates() {
+    let word = "galea";
+
+    let inputs = ["eagle"];
+
+    let outputs = vec![];
+
+    process_anagram_case(word, &inputs, &outputs);
+}
+
+#[test]
+fn test_eliminate_anagram_subsets() {
+    let word = "good";
+
+    let inputs = ["dog", "goody"];
+
+    let outputs = vec![];
+
+    process_anagram_case(word, &inputs, &outputs);
+}
+
+#[test]
+fn test_detect_anagram() {
+    let word = "listen";
+
+    let inputs = ["enlists", "google", "inlets", "banana"];
+
+    let outputs = vec!["inlets"];
+
+    process_anagram_case(word, &inputs, &outputs);
+}
+
+#[test]
+fn test_multiple_anagrams() {
+    let word = "allergy";
+
+    let inputs = [
+        "gallery",
+        "ballerina",
+        "regally",
+        "clergy",
+        "largely",
+        "leading",
+    ];
+
+    let outputs = vec!["gallery", "regally", "largely"];
+
+    process_anagram_case(word, &inputs, &outputs);
+}
+
+#[test]
+fn test_case_insensitive_anagrams() {
+    let word = "Orchestra";
+
+    let inputs = ["cashregister", "Carthorse", "radishes"];
+
+    let outputs = vec!["Carthorse"];
+
+    process_anagram_case(word, &inputs, &outputs);
+}
+
+#[test]
+fn test_unicode_anagrams() {
+    let word = "ΑΒΓ";
+
+    // These words don't make sense, they're just greek letters cobbled together.
+    let inputs = ["ΒΓΑ", "ΒΓΔ", "γβα"];
+
+    let outputs = vec!["ΒΓΑ", "γβα"];
+
+    process_anagram_case(word, &inputs, &outputs);
+}
+
+#[test]
+fn test_misleading_unicode_anagrams() {
+    // Despite what a human might think these words different letters, the input uses Greek A and B
+    // while the list of potential anagrams uses Latin A and B.
+    let word = "ΑΒΓ";
+
+    let inputs = ["ABΓ"];
+
+    let outputs = vec![];
+
+    process_anagram_case(word, &inputs, &outputs);
+}
+
+#[test]
+fn test_does_not_detect_a_word_as_its_own_anagram() {
+    let word = "banana";
+
+    let inputs = ["banana"];
+
+    let outputs = vec![];
+
+    process_anagram_case(word, &inputs, &outputs);
+}
+
+#[test]
+fn test_does_not_detect_a_differently_cased_word_as_its_own_anagram() {
+    let word = "banana";
+
+    let inputs = ["bAnana"];
+
+    let outputs = vec![];
+
+    process_anagram_case(word, &inputs, &outputs);
+}
+
+#[test]
+fn test_does_not_detect_a_differently_cased_unicode_word_as_its_own_anagram() {
+    let word = "ΑΒΓ";
+
+    let inputs = ["ΑΒγ"];
+
+    let outputs = vec![];
+
+    process_anagram_case(word, &inputs, &outputs);
+}
+
+#[test]
+fn test_same_bytes_different_chars() {
+    let word = "a⬂"; // 61 E2 AC 82
+
+    let inputs = ["€a"]; // E2 82 AC 61
+
+    let outputs = vec![];
+
+    process_anagram_case(word, &inputs, &outputs);
+}