From adc92c53b5b30d446065ec1b69fa245f9c6033a9 Mon Sep 17 00:00:00 2001
From: Ian Whitney <whit0694@umn.edu>
Date: Fri, 27 May 2016 13:49:27 -0500
Subject: [PATCH] Implement pangram

Implements the Pangram problem and follows the current canonical test
suite.

I'm putting the problem after scrabble score. I'm guessing that
Most implementations will use iter -> filter -> collect (though students
constantly surprise me with their great ideas). The track places
these iterator -> Higher Order Function problems around scrabble score &
hamming.
---
 config.json                        |  1 +
 exercises/pangram/Cargo.lock       |  4 ++
 exercises/pangram/Cargo.toml       |  3 ++
 exercises/pangram/example.rs       | 18 +++++++++
 exercises/pangram/tests/pangram.rs | 65 ++++++++++++++++++++++++++++++
 5 files changed, 91 insertions(+)
 create mode 100644 exercises/pangram/Cargo.lock
 create mode 100644 exercises/pangram/Cargo.toml
 create mode 100644 exercises/pangram/example.rs
 create mode 100644 exercises/pangram/tests/pangram.rs

diff --git a/config.json b/config.json
index 6ec384f78..de00f194f 100644
--- a/config.json
+++ b/config.json
@@ -13,6 +13,7 @@
     "difference-of-squares",
     "hamming",
     "scrabble-score",
+    "pangram",
     "nucleotide-count",
     "word-count",
     "etl",
diff --git a/exercises/pangram/Cargo.lock b/exercises/pangram/Cargo.lock
new file mode 100644
index 000000000..1cc06af97
--- /dev/null
+++ b/exercises/pangram/Cargo.lock
@@ -0,0 +1,4 @@
+[root]
+name = "pangram"
+version = "0.0.0"
+
diff --git a/exercises/pangram/Cargo.toml b/exercises/pangram/Cargo.toml
new file mode 100644
index 000000000..541dca162
--- /dev/null
+++ b/exercises/pangram/Cargo.toml
@@ -0,0 +1,3 @@
+[package]
+name = "pangram"
+version = "0.0.0"
diff --git a/exercises/pangram/example.rs b/exercises/pangram/example.rs
new file mode 100644
index 000000000..585d178d8
--- /dev/null
+++ b/exercises/pangram/example.rs
@@ -0,0 +1,18 @@
+use std::collections::BTreeSet;
+use std::ascii::AsciiExt;
+use std::iter::FromIterator;
+
+pub fn is_pangram(sentence: &str) -> bool {
+    sentence.to_lowercase()
+            .chars()
+            .filter(|c| c.is_alphabetic())
+            .filter(|c| c.is_ascii())
+            .collect::<BTreeSet<char>>() == english_letter_set()
+
+}
+
+fn english_letter_set() -> BTreeSet<char> {
+    BTreeSet::from_iter(ENGLISH_ALPHABET.chars())
+}
+
+const ENGLISH_ALPHABET: &'static str = "abcdefghijklmnopqrstuvwxyz";
diff --git a/exercises/pangram/tests/pangram.rs b/exercises/pangram/tests/pangram.rs
new file mode 100644
index 000000000..cc7da2baf
--- /dev/null
+++ b/exercises/pangram/tests/pangram.rs
@@ -0,0 +1,65 @@
+extern crate pangram;
+
+use pangram::*;
+
+#[test]
+fn empty_strings_are_not_pangrams() {
+    let sentence = "";
+    assert!(!is_pangram(&sentence));
+}
+
+#[test]
+#[ignore]
+fn classic_pangram_is_a_pangram() {
+    let sentence = "the quick brown fox jumps over the lazy dog";
+    assert!(is_pangram(&sentence));
+}
+
+#[test]
+#[ignore]
+fn pangrams_must_have_all_letters() {
+    let sentence = "a quick movement of the enemy will jeopardize five gunboats";
+    assert!(!is_pangram(&sentence));
+}
+
+#[test]
+#[ignore]
+fn pangrams_must_have_all_letters_two() {
+    let sentence = "the quick brown fish jumps over the lazy dog";
+    assert!(!is_pangram(&sentence));
+}
+
+#[test]
+#[ignore]
+fn underscores_do_not_affect_pangrams() {
+    let sentence = "the_quick_brown_fox_jumps_over_the_lazy_dog";
+    assert!(is_pangram(&sentence));
+}
+
+#[test]
+#[ignore]
+fn numbers_do_not_affect_pangrams() {
+    let sentence = "the 1 quick brown fox jumps over the 2 lazy dogs";
+    assert!(is_pangram(&sentence));
+}
+
+#[test]
+#[ignore]
+fn numbers_can_not_replace_numbers() {
+    let sentence = "7h3 qu1ck brown fox jumps ov3r 7h3 lazy dog";
+    assert!(!is_pangram(&sentence));
+}
+
+#[test]
+#[ignore]
+fn capitals_and_punctuation_can_be_in_pangrams() {
+    let sentence = "\"Five quacking Zephyrs jolt my wax bed.\"";
+    assert!(is_pangram(&sentence));
+}
+
+#[test]
+#[ignore]
+fn non_ascii_characters_can_be_in_pangrams() {
+    let sentence = "Victor jagt zwölf Boxkämpfer quer über den großen Sylter Deich.";
+    assert!(is_pangram(&sentence));
+}