kevin-cantwell/exceptions

This package is bad and you should feel bad for using it.

This package is bad and you shouldn't use it.

Seriously, don't even read this.

Turn back now.

Still here? Ok cool.

Package exceptions brings the old try/catch/finally pattern you know and love to Go. It's a complete abomination of everything that is holy about Go and if you use it your peers will mock you and your friends will abandon you. Here's how it works:

exceptions/_examples/gofishing/main.go

Lines 10 to 26 in e981e83

	Try(func() {
	fmt.Println("Trying to fish...")
	// cause a panic with a Shark
	panic(Shark{})
	}, Catch(func(cause Fish) {
	// gets skipped
	fmt.Println("I caught a Fish!")
	}), Catch(func(cause Shark) {
	// gets called
	fmt.Println("I caught a Shark!")
	}), Catch(func(cause Swimmer) {
	// gets skipped
	fmt.Println("I caught a Swimmer!")
	}), Finally(func() {
	// gets called
	fmt.Println("Stopped fishing.")
	}))

The above program outputs:

Trying to fish...
I caught a Shark!
Stopped fishing.

exceptions/_examples/runtime_error/main.go

Lines 10 to 20 in e981e83

	Try(func() {
	// cause a runtime error
	var a []int
	fmt.Println(a[2])
	}, Catch(func(cause any) {
	// will catch anything except nil
	fmt.Println("caught:", cause)
	}), Finally(func() {
	// gets called
	fmt.Println("This will print after catching the error.")
	}))

The above program outputs:

caught: runtime error: index out of range [2] with length 0
This will print after catching the error.

exceptions/_examples/nilpanic/main.go

Lines 10 to 19 in 28e7d3e

	Try(func() {
	// Typically, nil panics are not detected at runtime. But we can detect them if they
	// happen in the Try block.
	panic(nil)
	}, CatchNil(func(cause any) {
	fmt.Printf("nil panic! %T\n", cause)
	}), Finally(func() {
	// gets called
	fmt.Println("This will print after catching the error.")
	}))

The above program outputs:

nil panic! <nil>
This will print after catching the error.

This follows the semantics of try...catch...finally where any (optional) Finally funcs are invoked directly after Try any Catch that was invoked. The Catch functions take a single arguments: a "cause" of any type. The cause is any type you might expect to be recovered from a panic. Only the first catch that meets these requirements is invoked.

Ironically, this package declares no exception types.

Requires go version 1.18 or greater (for generics)