philiprehberger-guard-clause
v0.1.9122 downloadsMIT
Early-return guard clause macros for cleaner control flow
$
cargo add philiprehberger-guard-clauseREADME
rs-guard-clause
Early-return guard clause macros for cleaner control flow
Installation
[dependencies]
philiprehberger-guard-clause = "0.1.8"
Usage
use philiprehberger_guard_clause::{guard, ensure, reject, unwrap_or_return};
fn process_user(id: Option<u64>, name: &str) -> Result<String, &'static str> {
// Unwrap or return early
let id = unwrap_or_return!(id, Err("missing id"));
// Ensure conditions
ensure!(!name.is_empty(), "name is empty");
reject!(name.len() > 100, "name too long");
Ok(format!("User {}: {}", id, name))
}
fn find_item(items: &[Option<&str>], index: usize) -> Option<String> {
let item_opt = items.get(index)?;
guard!(let Some(item) = item_opt, return None);
Some(item.to_uppercase())
}
API
| Macro | Description |
|---|---|
guard!(let pat = expr, fallback) | Pattern match or execute fallback |
ensure!(cond, err) | Return Err(err) if condition is false |
reject!(cond, err) | Return Err(err) if condition is true |
unwrap_or_return!(expr, default) | Unwrap Option or return default |
Development
cargo test
cargo clippy -- -D warnings
Support
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