From 58ccf4d9584c0b2e99bd55849e5feccc87bf811c Mon Sep 17 00:00:00 2001 From: abhi3700 Date: Fri, 7 Apr 2023 19:58:19 +0530 Subject: [PATCH] added exercises to \'traits\' chapter --- exercises/traits/traits6.rs | 111 ++++++++++++++++++++++++++++++++++++ exercises/traits/traits7.rs | 73 ++++++++++++++++++++++++ info.toml | 22 +++++++ 3 files changed, 206 insertions(+) create mode 100644 exercises/traits/traits6.rs create mode 100644 exercises/traits/traits7.rs diff --git a/exercises/traits/traits6.rs b/exercises/traits/traits6.rs new file mode 100644 index 00000000..7c4da010 --- /dev/null +++ b/exercises/traits/traits6.rs @@ -0,0 +1,111 @@ +// traits6.rs +// +// Your task is to replace the '??' sections so the code compiles. +// Don't change any line other than the marked one. +// Execute `rustlings hint traits6` or use the `hint` watch subcommand for a hint. + +// I AM NOT DONE + +struct House { + area_sqft: u32, + purchase_date: String, +} + +struct Vehicle { + name: String, + model: String, + purchase_date: String, +} + +trait Details { + fn summary(&self) -> String; +} + +impl Details for House { + fn summary(&self) -> String { + format!( + "The house has an area of {} sqft and was purchased on {}", + self.area_sqft, self.purchase_date + ) + } +} +impl Details for Vehicle { + fn summary(&self) -> String { + format!( + "The {} vehicle with model {} was purchased on {}", + self.name, self.model, self.purchase_date + ) + } +} + +// TODO: Complete the code +fn foo(flag: bool) -> ?? { + if flag { + Box::new(House { + area_sqft: 5000, + purchase_date: "21 Nov 2017".to_string(), + }) + } else { + Box::new(Vehicle { + name: "BMW".to_string(), + model: "320d".to_string(), + purchase_date: "13 Aug 2022".to_string(), + }) + } +} + +#[cfg(test)] +mod test { + + use super::*; + + fn init() -> (House, Vehicle) { + let house = House { + area_sqft: 5000, + purchase_date: "21 Nov 2017".to_string(), + }; + let vehicle = Vehicle { + name: "BMW".to_string(), + model: "320d".to_string(), + purchase_date: "13 Aug 2022".to_string(), + }; + + (house, vehicle) + } + + #[test] + fn check_foo_returns_house_if_true() { + let (house, _) = init(); + assert_eq!(house.summary(), foo(true).summary()); + } + + #[test] + fn check_foo_returns_vehicle_if_false() { + let (_, vehicle) = init(); + assert_eq!(vehicle.summary(), foo(false).summary()); + } + + #[test] + fn check_purchase_date_for_house() { + let (house, _) = init(); + assert_eq!( + format!( + "The house has an area of {} sqft and was purchased on {}", + house.area_sqft, house.purchase_date + ), + house.summary() + ); + } + + #[test] + fn check_purchase_date_for_vehicle() { + let (_, vehicle) = init(); + assert_eq!( + format!( + "The {} vehicle with model {} was purchased on {}", + vehicle.name, vehicle.model, vehicle.purchase_date + ), + vehicle.summary() + ); + } +} diff --git a/exercises/traits/traits7.rs b/exercises/traits/traits7.rs new file mode 100644 index 00000000..ff05b335 --- /dev/null +++ b/exercises/traits/traits7.rs @@ -0,0 +1,73 @@ +// traits7.rs +// +// Your task is to replace the '??' sections so the code compiles. +// Don't change any line other than the marked one. +// Execute `rustlings hint traits7` or use the `hint` watch subcommand for a hint. + +// I AM NOT DONE + +#[allow(unused_imports)] +use std::fmt::{Debug, Formatter}; + +/// Struct representing a house +// TODO: Complete the Code +#[derive(??, Default)] +struct House { + area_sqft: u32, + purchase_date: String, +} + +/// Struct representing a vehicle +// TODO: Complete the Code +#[derive(??, Default)] +struct Vehicle { + name: String, + model: String, + purchase_date: String, +} + +// TODO: Complete the code +trait Details: ?? { + fn summary(&self) -> String; +} + +impl Details for House { + fn summary(&self) -> String { + format!( + "The house has an area of {} sqft and was purchased on {}", + self.area_sqft, self.purchase_date + ) + } +} +impl Details for Vehicle { + fn summary(&self) -> String { + format!( + "The {} vehicle with model {} was purchased on {}", + self.name, self.model, self.purchase_date + ) + } +} + +// TODO: Complete the code +fn foo(flag: bool) -> ?? { + if flag { + Box::new(House { + area_sqft: 5000, + purchase_date: "21 Nov 2017".to_string(), + }) + } else { + Box::new(Vehicle { + name: "BMW".to_string(), + model: "320d".to_string(), + purchase_date: "13 Aug 2022".to_string(), + }) + } +} + +pub fn main() { + let x = foo(true); + println!("{:?}", x); + // TODO: Complete the code + // print the summary of the struct returned from the function `foo` + println!("{}", ??); +} diff --git a/info.toml b/info.toml index 28f9bb31..cc91a76b 100644 --- a/info.toml +++ b/info.toml @@ -737,6 +737,28 @@ To ensure a parameter implements multiple traits use the '+ syntax'. Try replaci See the documentation at: https://doc.rust-lang.org/book/ch10-02-traits.html#specifying-multiple-trait-bounds-with-the--syntax """ +[[exercises]] +name = "traits6" +path = "exercises/traits/traits6.rs" +mode = "test" +hint = """ +To ensure a function is able to return incompatible types can be done by using a trait bound that is common to them. +Wrap the shared trait (implemented by the 2 struct types/objects) as a Boxed trait object. Try replacing the '??' with Box<_> + +See the documentation at: https://doc.rust-lang.org/book/ch10-02-traits.html#returning-types-that-implement-traits +""" + +[[exercises]] +name = "traits7" +path = "exercises/traits/traits7.rs" +mode = "compile" +hint = """ +To make the function printable on console using `:?` symbol. Use the `Debug` trait for the `Details` trait. +Here, if the trait implements `Debug` trait then the corresponding struct types also has to implement `Debug` trait, +otherwise the function returning trait object will not be printable on console. +See the documentation at: https://doc.rust-lang.org/std/fmt/trait.Debug.html +""" + # QUIZ 3 [[exercises]]