try

README

try

Documentation

Overview

Package try simplifies the error handling in waiting Go 2 error handling.

It is not the perfect solution, and it is not recommended to use in the libraries, but it can help for the simple apps.

In Go it is common to handle errors like this:

func foo() error {
  v, err := bar()
  if err != nil {
    return err
  }

  if err := bar2(v); err != nil {
    return err
  }

  return nil
}

It gets tedious when there are a lot of these checks. With the try package you can replace this code to:

func foo() (outErr error) {
  defer try.HandleAs(*outErr)

  v := try.ItVal(bar())

  try.It(bar2(v))

  return nil
}

Index

• func Handle(fn func(error), ws ...Wrapper)
• func HandleAs(targetError *error, ws ...Wrapper)
• func It(err error)
• func ItVal[T any](val T, err error) T
• func Throw(err error)
• func UnboxError(val any) (error, bool)
• type Result
  • func Check(err error) *Result[struct{}]
  • func CheckVal[T any](val T, err error) *Result[T]
  • func (r *Result[T]) Allow(errs ...error) (T, error)
  • func (r *Result[T]) AllowOr(errs ...error) *Result[T]
  • func (r *Result[T]) Annotate(format string, args ...any) T
  • func (r *Result[T]) Err() error
  • func (r *Result[T]) Val() T
  • func (r *Result[T]) Wrap(ws ...Wrapper) T
  • func (r *Result[T]) WrapOr(ws ...Wrapper) *Result[T]
• type Wrapper
  • func Annotate(format string, args ...any) Wrapper

Examples

• It
• ItVal

Functions

func Handle

func Handle(fn func(error), ws ...Wrapper)

func HandleAs

func HandleAs(targetError *error, ws ...Wrapper)

func It

func It(err error)

Example

package main

import (
	"encoding/json"
	"fmt"

	"github.com/davidmz/try"
)

func main() {
	defer try.Handle(func(err error) {
		fmt.Println("Oh,", err)
	})

	goodData := []byte(`"Good JSON"`)
	badData := []byte(`Bad JSON`)
	value := ""

	try.It(json.Unmarshal(goodData, &value))
	fmt.Println(value)

	try.It(json.Unmarshal(badData, &value))
	fmt.Println(value)

}

Output:

Good JSON
Oh, invalid character 'B' looking for beginning of value

func ItVal

func ItVal[T any](val T, err error) T

Example

package main

import (
	"encoding/json"
	"fmt"

	"github.com/davidmz/try"
)

func main() {
	defer try.Handle(func(err error) {
		fmt.Println("Oh,", err)
	})

	goodValue := "Good value"
	badValue := func() {} // functions cannot be serialized
	var data []byte

	data = try.ItVal(json.Marshal(goodValue))
	fmt.Println(string(data))

	data = try.ItVal(json.Marshal(badValue))
	fmt.Println(string(data))

}

Output:

"Good value"
Oh, json: unsupported type: func()

func Throw

func Throw(err error)

func UnboxError

func UnboxError(val any) (error, bool)

Types

type Result

type Result[T any] struct {
	// contains filtered or unexported fields
}

func Check

func Check(err error) *Result[struct{}]

func CheckVal

func CheckVal[T any](val T, err error) *Result[T]

func (*Result[T]) Allow

func (r *Result[T]) Allow(errs ...error) (T, error)

func (*Result[T]) AllowOr

func (r *Result[T]) AllowOr(errs ...error) *Result[T]

func (*Result[T]) Annotate

func (r *Result[T]) Annotate(format string, args ...any) T

func (*Result[T]) Err

func (r *Result[T]) Err() error

func (*Result[T]) Val

func (r *Result[T]) Val() T

func (*Result[T]) Wrap

func (r *Result[T]) Wrap(ws ...Wrapper) T

func (*Result[T]) WrapOr

func (r *Result[T]) WrapOr(ws ...Wrapper) *Result[T]

type Wrapper

type Wrapper func(error) error

func Annotate

func Annotate(format string, args ...any) Wrapper