proverb

rust/proverb/.exercism/config.json

@@ -0,0 +1,36 @@
+{
+  "authors": [
+    "sacherjj"
+  ],
+  "contributors": [
+    "attilahorvath",
+    "coriolinus",
+    "cwhakes",
+    "efx",
+    "ErikSchierboom",
+    "leoyvens",
+    "lutostag",
+    "navossoc",
+    "nfiles",
+    "petertseng",
+    "rofrol",
+    "stringparser",
+    "xakon",
+    "ZapAnton"
+  ],
+  "files": {
+    "solution": [
+      "src/lib.rs",
+      "Cargo.toml"
+    ],
+    "test": [
+      "tests/proverb.rs"
+    ],
+    "example": [
+      ".meta/example.rs"
+    ]
+  },
+  "blurb": "For want of a horseshoe nail, a kingdom was lost, or so the saying goes. Output the full text of this proverbial rhyme.",
+  "source": "Wikipedia",
+  "source_url": "https://en.wikipedia.org/wiki/For_Want_of_a_Nail"
+}

rust/proverb/.gitignore

@@ -0,0 +1,2 @@
+/target
+Cargo.lock

rust/proverb/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "proverb"
+version = "0.1.0"
+edition = "2024"
+
+# Not all libraries from crates.io are available in Exercism's test runner.
+# The full list of available libraries is here:
+# https://github.com/exercism/rust-test-runner/blob/main/local-registry/Cargo.toml
+[dependencies]

rust/proverb/HELP.md

@@ -0,0 +1,89 @@
+# Help
+
+## Running the tests
+
+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 _only ignored_ tests without editing the tests source file, use:
+
+```bash
+$ cargo test -- --ignored
+```
+
+If you are using Rust 1.51 or later, you can run _all_ tests with
+
+```bash
+$ cargo test -- --include-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].
+
+[rust-tests]: https://doc.rust-lang.org/book/ch11-02-running-tests.html
+
+## Submitting your solution
+
+You can submit your solution using the `exercism submit src/lib.rs Cargo.toml` command.
+This command will upload your solution to the Exercism website and print the solution page's URL.
+
+It's possible to submit an incomplete solution which allows you to:
+
+- See how others have completed the exercise
+- Request help from a mentor
+
+## Need to get help?
+
+If you'd like help solving the exercise, check the following pages:
+
+- The [Rust track's documentation](https://exercism.org/docs/tracks/rust)
+- The [Rust track's programming category on the forum](https://forum.exercism.org/c/programming/rust)
+- [Exercism's programming category on the forum](https://forum.exercism.org/c/programming/5)
+- The [Frequently Asked Questions](https://exercism.org/docs/using/faqs)
+
+Should those resources not suffice, you could submit your (incomplete) solution to request mentoring.
+
+## Rust Installation
+
+Refer to the [exercism help page][help-page] for Rust installation and learning
+resources.
+
+## 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
+
+Head to [the forum](https://forum.exercism.org/c/programming/rust/) and create a post to provide feedback about an exercise or if you want to help implement new exercises.
+Members of the rust track team are happy to help!
+
+The GitHub [track repository][github] is the home for all of the Rust exercises.
+
+If you want to know more about Exercism, take a look at the [contribution guide].
+
+## Submitting Incomplete Solutions
+It's possible to submit an incomplete solution so you can see how others have completed the exercise.
+
+[help-page]: https://exercism.org/tracks/rust/learning
+[github]: https://github.com/exercism/rust
+[contribution guide]: https://exercism.org/docs/community/contributors

rust/proverb/README.md

@@ -0,0 +1,51 @@
+# Proverb
+
+Welcome to Proverb on Exercism's Rust Track.
+If you need help running the tests or submitting your code, check out `HELP.md`.
+
+## Instructions
+
+For want of a horseshoe nail, a kingdom was lost, or so the saying goes.
+
+Given a list of inputs, generate the relevant proverb.
+For example, given the list `["nail", "shoe", "horse", "rider", "message", "battle", "kingdom"]`, you will output the full text of this proverbial rhyme:
+
+```text
+For want of a nail the shoe was lost.
+For want of a shoe the horse was lost.
+For want of a horse the rider was lost.
+For want of a rider the message was lost.
+For want of a message the battle was lost.
+For want of a battle the kingdom was lost.
+And all for the want of a nail.
+```
+
+Note that the list of inputs may vary; your solution should be able to handle lists of arbitrary length and content.
+No line of the output text should be a static, unchanging string; all should vary according to the input given.
+
+## Source
+
+### Created by
+
+- @sacherjj
+
+### Contributed to by
+
+- @attilahorvath
+- @coriolinus
+- @cwhakes
+- @efx
+- @ErikSchierboom
+- @leoyvens
+- @lutostag
+- @navossoc
+- @nfiles
+- @petertseng
+- @rofrol
+- @stringparser
+- @xakon
+- @ZapAnton
+
+### Based on
+
+Wikipedia - https://en.wikipedia.org/wiki/For_Want_of_a_Nail

rust/proverb/src/lib.rs

@@ -0,0 +1,14 @@
+pub fn build_proverb(list: &[&str]) -> String {
+    if list.is_empty() {
+        return String::new();
+    }
+
+    list.windows(2)
+        .map(|pair| format!("For want of a {} the {} was lost.", pair[0], pair[1]))
+        .chain(std::iter::once(format!(
+            "And all for the want of a {}.",
+            list[0]
+        )))
+        .collect::<Vec<_>>()
+        .join("\n")
+}

rust/proverb/tests/proverb.rs

@@ -0,0 +1,75 @@
+use proverb::*;
+
+#[test]
+fn zero_pieces() {
+    let input = &[];
+    let output = build_proverb(input);
+    let expected = String::new();
+    assert_eq!(output, expected);
+}
+
+#[test]
+fn one_piece() {
+    let input = &["nail"];
+    let output = build_proverb(input);
+    let expected: String = ["And all for the want of a nail."].join("\n");
+    assert_eq!(output, expected);
+}
+
+#[test]
+fn two_pieces() {
+    let input = &["nail", "shoe"];
+    let output = build_proverb(input);
+    let expected: String = [
+        "For want of a nail the shoe was lost.",
+        "And all for the want of a nail.",
+    ]
+    .join("\n");
+    assert_eq!(output, expected);
+}
+
+#[test]
+fn three_pieces() {
+    let input = &["nail", "shoe", "horse"];
+    let output = build_proverb(input);
+    let expected: String = [
+        "For want of a nail the shoe was lost.",
+        "For want of a shoe the horse was lost.",
+        "And all for the want of a nail.",
+    ]
+    .join("\n");
+    assert_eq!(output, expected);
+}
+
+#[test]
+fn full_proverb() {
+    let input = &[
+        "nail", "shoe", "horse", "rider", "message", "battle", "kingdom",
+    ];
+    let output = build_proverb(input);
+    let expected: String = [
+        "For want of a nail the shoe was lost.",
+        "For want of a shoe the horse was lost.",
+        "For want of a horse the rider was lost.",
+        "For want of a rider the message was lost.",
+        "For want of a message the battle was lost.",
+        "For want of a battle the kingdom was lost.",
+        "And all for the want of a nail.",
+    ]
+    .join("\n");
+    assert_eq!(output, expected);
+}
+
+#[test]
+fn four_pieces_modernized() {
+    let input = &["pin", "gun", "soldier", "battle"];
+    let output = build_proverb(input);
+    let expected: String = [
+        "For want of a pin the gun was lost.",
+        "For want of a gun the soldier was lost.",
+        "For want of a soldier the battle was lost.",
+        "And all for the want of a pin.",
+    ]
+    .join("\n");
+    assert_eq!(output, expected);
+}