README.md

exceptions

Simple exceptions support for Go, using panic() and recover().

Go's panic(any) will unwind the stack one frame at a time until there is a matching call to recover(). This library calls the parameter passed to panic an exception, and provides simplified methods to catch those exceptions.

Examples

Catching any exception with Try

An exception in Go is what goes into the panic() call. The returned value (exception in the example) is of type any.

import . "github.com/gomlx/exceptions"

...
	exception := Try(func() { panic("cookies") })
	if exception != nil {
		fmt.Printf("Caught: %v\n", exception)
	}

It will print: Caught: cookies.

Throwing an exception with Panicf

We keep the Go word term for it, panic: one can simply use panic as usual, or use the provided Panicf, which converts the given text into an error+stack:

import . "github.com/gomlx/exceptions"

func MyRatio(myThing, total float64) float64 {
	if total == 0 {
		Panicf("MyRatio(%f, %f) has no things (0) to calculate a ratio from", myThing, total)
	}
	return myThing/total
}

Catching Typed Exceptions with TryCatch

Go panic() supports any value to be passed -- the value is what we interpret as an exception.

The generic TryCatch[E any] API allows a function to be called and an exception of the given type E to be caught. Any other exception types are not handled and continues to propagate up the stack as usual.

import . "github.com/gomlx/exceptions"

	var x ResultType
	err := TryCatch[error](func() { x = DoSomething() })
	if err != nil {
		// Handle error ...
	}