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Diffstat (limited to 'exercises/conversions/from_str.rs')
| -rw-r--r-- | exercises/conversions/from_str.rs | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/exercises/conversions/from_str.rs b/exercises/conversions/from_str.rs new file mode 100644 index 0000000..247ae14 --- /dev/null +++ b/exercises/conversions/from_str.rs @@ -0,0 +1,48 @@ +// This does practically the same thing that TryFrom<&str> does. +// Additionally, upon implementing FromStr, you can use the `parse` method +// on strings to generate an object of the implementor type. +// You can read more about it at https://doc.rust-lang.org/std/str/trait.FromStr.html +use std::str::FromStr; + +#[derive(Debug)] +struct Person { + name: String, + age: usize, +} + +// Steps: +// 1. If the length of the provided string is 0, then return an error +// 2. Split the given string on the commas present in it +// 3. Extract the first element from the split operation and use it as the name +// 4. Extract the other element from the split operation and parse it into a `usize` as the age +// If while parsing the age, something goes wrong, then return an error +// Otherwise, then return a Result of a Person object +impl FromStr for Person { + type Err = String; + fn from_str(s: &str) -> Result<Person, Self::Err> { + } +} + +fn main() { + let p = "Mark,20".parse::<Person>().unwrap(); + println!("{:?}", p); +} + +#[cfg(test)] +mod tests { + use super::*; + + #[test] + fn empty_input() { + assert!("".parse::<Person>().is_err()); + } + #[test] + fn good_input() { + assert!("John,32".parse::<Person>().is_ok()); + } + #[test] + #[should_panic] + fn missing_age() { + "John".parse::<Person>().unwrap(); + } +}
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