From 9f4be26dc4fcb3889fb62dbde03c511698326f60 Mon Sep 17 00:00:00 2001
From: IkaR49 <IkaR49@users.noreply.github.com>
Date: Tue, 12 May 2020 22:56:46 +0300
Subject: [PATCH] fix(try_from_into): Rewrite exercise
Instead of working with strings, the exercise suggests creating a Color structure from other simple types (tuple, array, slice).
closes #392
---
exercises/conversions/try_from_into.rs | 130 +++++++++++++------------
1 file changed, 66 insertions(+), 64 deletions(-)
diff --git a/exercises/conversions/try_from_into.rs b/exercises/conversions/try_from_into.rs
index 9968075..fafa198 100644
--- a/exercises/conversions/try_from_into.rs
+++ b/exercises/conversions/try_from_into.rs
@@ -5,98 +5,100 @@
use std::convert::{TryInto, TryFrom};
#[derive(Debug)]
-struct Person {
- name: String,
- age: usize,
+struct Color {
+ red: u8,
+ green: u8,
+ blue: u8,
}
// I AM NOT DONE
-// Your task is to complete this implementation
-// in order for the line `let p = Person::try_from("Mark,20")` to compile
-// and return an Ok result of inner type Person.
-// Please note that you'll need to parse the age component into a `usize`
-// with something like `"4".parse::<usize>()`. The outcome of this needs to
-// be handled appropriately.
-//
-// 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. If the name is empty, then return an error.
-// 5. 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 TryFrom<&str> for Person {
+
+impl TryFrom<(i16, i16, i16)> for Color {
type Error = String;
- fn try_from(s: &str) -> Result<Self, Self::Error> {
+ fn try_from(tuple: (i16, i16, i16)) -> Result<Self, Self::Error> {
+ }
+}
+
+impl TryFrom<[i16; 3]> for Color {
+ type Error = String;
+ fn try_from(arr: [i16; 3]) -> Result<Self, Self::Error> {
+ }
+}
+
+impl TryFrom<&[i16]> for Color {
+ type Error = String;
+ fn try_from(slice: &[i16]) -> Result<Self, Self::Error> {
}
}
fn main() {
// Use the `from` function
- let p1 = Person::try_from("Mark,20");
- // Since From is implemented for Person, we should be able to use Into
- let p2: Result<Person, _> = "Gerald,70".try_into();
- println!("{:?}", p1);
- println!("{:?}", p2);
+ let c1 = Color::try_from((183, 65, 14));
+ println!("{:?}", c1);
+
+ // Since From is implemented for Color, we should be able to use Into
+ let c2: Result<Color, _> = [183, 65, 14].try_into();
+ println!("{:?}", c2);
+
+ let v = vec![183, 65, 14];
+ // With slice we should use `from` function
+ let c3 = Color::try_from(&v[..]);
+ println!("{:?}", c3);
+ // or take slice within round brackets
+ let c4: Result<Color, _> = (&v[..]).try_into();
+ println!("{:?}", c4);
}
#[cfg(test)]
mod tests {
use super::*;
- #[test]
- fn test_bad_convert() {
- // Test that error is returned when bad string is provided
- let p = Person::try_from("");
- assert!(p.is_err());
- }
- #[test]
- fn test_good_convert() {
- // Test that "Mark,20" works
- let p = Person::try_from("Mark,20");
- assert!(p.is_ok());
- let p = p.unwrap();
- assert_eq!(p.name, "Mark");
- assert_eq!(p.age, 20);
- }
+
#[test]
#[should_panic]
- fn test_panic_empty_input() {
- let p: Person = "".try_into().unwrap();
+ fn test_bad_tuple() {
+ let _: Color = Color::try_from((-1, 0, 0)).unwrap();
}
#[test]
- #[should_panic]
- fn test_panic_bad_age() {
- let p = Person::try_from("Mark,twenty").unwrap();
+ fn test_good_tuple() {
+ let c: Color = (183, 65, 14).try_into().unwrap();
+ assert_eq!(c.red, 183);
+ assert_eq!(c.green, 65);
+ assert_eq!(c.blue, 14);
}
#[test]
#[should_panic]
- fn test_missing_comma_and_age() {
- let _: Person = "Mark".try_into().unwrap();
+ fn test_bad_array() {
+ let _: Color = [0, -1, 0].try_into().unwrap();
+ }
+ #[test]
+ fn test_good_array() {
+ let c: Color = [183, 65, 14].try_into().unwrap();
+
+ assert_eq!(c.red, 183);
+ assert_eq!(c.green, 65);
+ assert_eq!(c.blue, 14);
}
#[test]
#[should_panic]
- fn test_missing_age() {
- let _: Person = "Mark,".try_into().unwrap();
+ fn test_bad_slice() {
+ let arr = [0, 0, -1];
+ let _ = Color::try_from(&arr[..]).unwrap();
}
+ #[test]
+ fn test_good_slice() {
+ let v = vec![183, 65, 14];
+ let c = Color::try_from(&v[..]).unwrap();
+ assert_eq!(c.red, 183);
+ assert_eq!(c.green, 65);
+ assert_eq!(c.blue, 14);
+ }
#[test]
#[should_panic]
- fn test_missing_name() {
- let _ : Person = ",1".try_into().unwrap();
+ fn test_bad_slice_length() {
+ let v = vec![0, 0, 0, 0];
+ let _ = Color::try_from(&v[..]).unwrap();
}
-
- #[test]
- #[should_panic]
- fn test_missing_name_and_age() {
- let _: Person = ",".try_into().unwrap();
- }
-
- #[test]
- #[should_panic]
- fn test_missing_name_and_invalid_age() {
- let _: Person = ",one".try_into().unwrap();
- }
-}
\ No newline at end of file
+}