public/subjects/blood_types

blood_types

Instructions

In this exercise you will create a data model of blood types and an API to deal with them.

First, we'll implement the data representation of the blood types.

Take a look at the BloodType struct below. It contains two enums which enable us to describe a blood type (e.g. "A-").

• Antigen: which can be one of:
  • A
  • B
  • AB
  • O
• RhFactor: which can be one of:
  • Positive
  • Negative

To provide a simple way to create blood types, implement the trait FromStr for BloodType. This will allow us to use the parse method and from_str, so we can do:

   let a_neg: BloodType = "A-".parse();

Implement the following Traits:

• std::cmp::Ord: to make possible to sort a vector or array of BloodType.
• std::Debug: for BloodType, allowing us print a vector such as [BloodType { antigen: A, rh_factor: Positive}, BloodType{ antigen: B, rh_factor: Negative}] as "[ A+, B-]" when using format strings {:?}.

Create three methods for BloodType:

• can_receive_from: which returns true if self can receive blood from other blood type.
• donors: which returns all the blood types that can give blood to self.
• recipients: which returns all the blood types that can receive blood from self.

Expected Functions and Structures

#[derive(Debug, PartialEq, Eq, Clone, PartialOrd, Ord)]
pub enum Antigen {
	A,
	AB,
	B,
	O,
}

#[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Clone)]
enum RhFactor {
	Positive,
	Negative,
}

#[derive(PartialEq, Eq, PartialOrd)]
pub struct BloodType {
	pub antigen: Antigen,
	pub rh_factor: RhFactor,
}

use std::cmp::{Ord, Ordering};

use std::str::FromStr;

impl FromStr for Antigen {
}

impl FromStr for RhFactor {
}

impl Ord for BloodType {
}

impl FromStr for BloodType {
}

use std::fmt::{self, Debug};

impl Debug for BloodType {
}

impl BloodType {
	pub fn can_receive_from(&self, other: &Self) -> bool {
	}

	pub fn donors(&self) -> Vec<Self> {
	}

	pub fn recipients(&self) -> Vec<BloodType> {
}

Usage

Here is a program to test your function.

use blood_types::*;

fn main() {
	let blood_type: BloodType = "O+".parse().unwrap();
	println!("recipients of O+ {:?}", blood_type.recipients());
	println!("donors of O+ {:?}", blood_type.donors());
	let another_blood_type: BloodType = "A-".parse().unwrap();
	println!(
		"donors of O+ can receive from {:?} {:?}",
		&another_blood_type,
		blood_type.can_receive_from(&another_blood_type)
	);
}

And its output

$ cargo run
recipients of O+ [AB+, O+, A+, B+]
donors of O+ [O+, O-]
donors of O+ can receive from A- false
$