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34 lines
1.1 KiB
Rust
34 lines
1.1 KiB
Rust
// errors3.rs
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// This is a program that is trying to use a completed version of the
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// `total_cost` function from the previous exercise. It's not working though!
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// Why not? What should we do to fix it?
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// Execute `rustlings hint errors3` for hints!
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// I AM NOT DONE
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use std::num::ParseIntError;
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fn main() -> Result<(),ParseIntError> { // This isn't too bad, main should return (), so we just float the result structure up to main.
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let mut tokens = 100;
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let pretend_user_input = "8";
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let cost = total_cost(pretend_user_input)?; // Here we're making cost a result
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if cost > tokens {
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println!("You can't afford that many!");
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} else {
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tokens -= cost;
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println!("You now have {} tokens.", tokens);
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}
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Ok(()) // :facepalm: So, I was on https://doc.rust-lang.org/book/ch09-02-recoverable-errors-with-result.html at the final example.
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// Wish I had read further
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}
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pub fn total_cost(item_quantity: &str) -> Result<i32, ParseIntError> {
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let processing_fee = 1;
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let cost_per_item = 5;
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let qty = item_quantity.parse::<i32>()?;
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Ok(qty * cost_per_item + processing_fee)
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}
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