handle-this - Ergonomic error handling with try/catch/throw/inspect/finally
§Overview
handle-this provides composable error handling with automatic stack traces.
All invocations return Result<T> - no hidden control flow.
§Quick Start
use handle_this::{handle, Result};
fn load_data(path: &str) -> Result<String> {
handle!{ try { std::fs::read_to_string(path)? } with "reading" }
}
§Patterns
§Basic
| Pattern | Description |
|---|
try { } | Execute, wrap error with trace |
try { } catch e { } | Recover from error |
try { } catch Type(e) { } | Recover only specific type |
try { } catch Type(e) { } else { } | Typed catch with fallback |
try { } try catch e { } | Fallible recovery (body returns Result) |
try { } throw e { } | Transform error |
try { } throw Type(e) { } | Transform only specific type |
try { } inspect e { } | Side effect, then propagate |
try { } finally { } | Cleanup always runs |
try -> T { } else { } | Infallible (returns T, not Result) |
§Guards
| Pattern | Description |
|---|
catch e when cond { } | Conditional catch |
catch Type(e) when cond { } | Typed with guard |
throw e when cond { } | Conditional transform |
catch Type(e) match expr { arms } | Match on error value |
§Chain Search
| Pattern | Description |
|---|
catch any Type(e) { } | First matching error in cause chain |
catch all Type |errs| { } | All matching errors as Vec |
§Context
| Pattern | Description |
|---|
try { } with "message" | Add context message |
try { } with { key: val } | Add structured data |
try { } with "msg", { key: val } | Both message and data |
scope "name", try { } | Hierarchical scope |
require cond else "msg", try { } | Precondition check |
§Chaining
| Pattern | Description |
|---|
try { a()? }, then |x| { b(x)? } | Chain operations |
§Iteration
| Pattern | Description |
|---|
try for x in iter { } | First success |
try any x in iter { } | Alias for try for |
try all x in iter { } | Collect all results |
try while cond { } | Retry loop |
§Async
| Pattern | Description |
|---|
async try { } | Async version (all patterns supported) |