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-rw-r--r--exercises/standard_library_types/iterators2.rs145
-rw-r--r--info.toml4
2 files changed, 149 insertions, 0 deletions
diff --git a/exercises/standard_library_types/iterators2.rs b/exercises/standard_library_types/iterators2.rs
new file mode 100644
index 0000000..d102dc9
--- /dev/null
+++ b/exercises/standard_library_types/iterators2.rs
@@ -0,0 +1,145 @@
+// iterators2.rs
+// In this module, you'll learn some of unique advantages that iterators can offer
+// Step 1. Complete the `capitalize_first` function to pass the first two cases
+// Step 2. Apply the `capitalize_first` function to a vector of strings, ensuring that it
+// Step 3. Apply the `capitalize_first` function again to a list, but try and ensure it returns a single string
+// As always, there are hints below!
+
+pub fn capitalize_first(input: &str) -> String {
+ let mut c = input.chars();
+ match c.next() {
+ None => String::new(),
+ Some(first) => first.collect()::<String>() + c.as_str(),
+ }
+}
+
+#[cfg(test)]
+mod tests {
+ use super::*;
+
+ // Step 1.
+ // Tests that verify your `capitalize_first` function implementation
+ #[test]
+ fn test_success() {
+ assert_eq!(capitalize_first("hello"), "Hello");
+ }
+
+ #[test]
+ fn test_empty() {
+ assert_eq!(capitalize_first(""), "");
+ }
+
+ // Step 2.
+ #[test]
+ fn test_iterate_string_vec() {
+ let words = vec!["hello", "world"];
+ let capitalized_words: Vec<String> = // TODO
+ assert_eq!(capitalized_words, ["Hello", "World"]);
+ }
+
+ #[test]
+ fn test_iterate_into_string() {
+ let words = vec!["hello", " ", "world"];
+ let capitalized_words = // TODO
+ assert_eq!(capitalized_words, "Hello World");
+ }
+}
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+// Step 1
+// You need to call something on `first` before it can be collected
+// Currently it's type is `char`. Have a look at the methods that are available on that type:
+// https://doc.rust-lang.org/std/primitive.char.html
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+// Step 2
+// First you'll need to turn the Vec into an iterator
+// Then you'll need to apply your function unto each item in the vector
+// P.s. Don't forget to collect() at the end!
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+// Step 3.
+// This is very similar to the previous test. The only real change is that you will need to
+// alter the type that collect is coerced into. For a bonus you could try doing this with a
+// turbofish
diff --git a/info.toml b/info.toml
index 2eb34ef..6c4f639 100644
--- a/info.toml
+++ b/info.toml
@@ -211,6 +211,10 @@ path = "exercises/standard_library_types/arc1.rs"
mode = "compile"
[[exercises]]
+path = "exercises/standard_library_types/iterators2.rs"
+mode = "test"
+
+[[exercises]]
path = "exercises/standard_library_types/iterators3.rs"
mode = "test"