error_handling done

This commit is contained in:
David E. Perez Negron R. 2024-04-26 00:18:06 -06:00
parent 4f31cb6daf
commit bfe2e1d8f0
6 changed files with 16 additions and 16 deletions

View File

@ -9,14 +9,12 @@
// Execute `rustlings hint errors1` or use the `hint` watch subcommand for a
// hint.
// I AM NOT DONE
pub fn generate_nametag_text(name: String) -> Option<String> {
pub fn generate_nametag_text(name: String) -> Result<String, String> {
if name.is_empty() {
// Empty names aren't allowed.
None
Err(format!("`name` was empty; it must be nonempty."))
} else {
Some(format!("Hi! My name is {}", name))
Ok(format!("Hi! My name is {}", name))
}
}

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@ -19,14 +19,13 @@
// Execute `rustlings hint errors2` or use the `hint` watch subcommand for a
// hint.
// I AM NOT DONE
use std::num::ParseIntError;
pub fn total_cost(item_quantity: &str) -> Result<i32, ParseIntError> {
let processing_fee = 1;
let cost_per_item = 5;
let qty = item_quantity.parse::<i32>();
let qty = item_quantity.parse::<i32>()?;
Ok(qty * cost_per_item + processing_fee)
}

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@ -7,7 +7,6 @@
// Execute `rustlings hint errors3` or use the `hint` watch subcommand for a
// hint.
// I AM NOT DONE
use std::num::ParseIntError;
@ -15,7 +14,7 @@ fn main() {
let mut tokens = 100;
let pretend_user_input = "8";
let cost = total_cost(pretend_user_input)?;
let cost = total_cost(pretend_user_input).expect("Parse Int Error");
if cost > tokens {
println!("You can't afford that many!");

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@ -3,7 +3,6 @@
// Execute `rustlings hint errors4` or use the `hint` watch subcommand for a
// hint.
// I AM NOT DONE
#[derive(PartialEq, Debug)]
struct PositiveNonzeroInteger(u64);
@ -16,8 +15,11 @@ enum CreationError {
impl PositiveNonzeroInteger {
fn new(value: i64) -> Result<PositiveNonzeroInteger, CreationError> {
// Hmm... Why is this always returning an Ok value?
Ok(PositiveNonzeroInteger(value as u64))
match value.signum() {
-1 => Err(CreationError::Negative),
0 => Err(CreationError::Zero),
_ => Ok(PositiveNonzeroInteger(value as u64))
}
}
}

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@ -22,14 +22,13 @@
// Execute `rustlings hint errors5` or use the `hint` watch subcommand for a
// hint.
// I AM NOT DONE
use std::error;
use std::fmt;
use std::num::ParseIntError;
// TODO: update the return type of `main()` to make this compile.
fn main() -> Result<(), Box<dyn ???>> {
fn main() -> Result<(), Box<dyn error::Error>> {
let pretend_user_input = "42";
let x: i64 = pretend_user_input.parse()?;
println!("output={:?}", PositiveNonzeroInteger::new(x)?);

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@ -9,7 +9,6 @@
// Execute `rustlings hint errors6` or use the `hint` watch subcommand for a
// hint.
// I AM NOT DONE
use std::num::ParseIntError;
@ -26,12 +25,16 @@ impl ParsePosNonzeroError {
}
// TODO: add another error conversion function here.
// fn from_parseint...
fn from_parseint(err: ParseIntError) -> ParsePosNonzeroError {
ParsePosNonzeroError::ParseInt(err)
}
}
fn parse_pos_nonzero(s: &str) -> Result<PositiveNonzeroInteger, ParsePosNonzeroError> {
// TODO: change this to return an appropriate error instead of panicking
// when `parse()` returns an error.
let x: i64 = s.parse().unwrap();
//let x: i64 = s.parse().unwrap();
let x: i64 = s.parse().map_err(ParsePosNonzeroError::from_parseint)?;
PositiveNonzeroInteger::new(x).map_err(ParsePosNonzeroError::from_creation)
}