adverr/README.md

# adverr
--
    import "adverr"

Package adverr implements errors with call stack traces as well as error
templates for error equality


Usage examples

Creating templates:

    var (
    	ErrDoStuffFailed = adverr.NewErrTmpl("ErrDoStuffFailed", "Could'nt do stuff because of %s")
    )

Creating independent error (without error template):

    func doStuffWithIndependentErr() error {
    	return adverr.New("Could'nt do stuff")
    }

Creating error based on template:

    func doStuff() error {
    	return ErrDoStuffFailed.New("reasons")
    }

Printing errors on stderr convieniently:

    Print(myErr)
    Println(myErr)

Printing errors on stderr and exit with exitcode:

    Fatal(myErr, 1)
    Fatalln(myErr, 1)

Advantages of error templates

    two errors made by the same template will return true when called with errors.Is()

## Usage

```go
var CallStackLength int = 100
```
CallStackLength decides how many calls from the call stack should be gathered at
most

```go
var (
	// ErrTmplUsedAsErr is returned from ErrTmpl.Error() because an error template should never be used as an actual error value
	ErrTmplUsedAsErr = NewErrTmpl("ErrTmplUsedAsErr", "Error template used as error value: %s")
)
```

```go
var TraceCallStack bool = true
```
TraceCallStack decides if any call stack traces will be gathered when creating
Errors If your application is doing performance-heavy tasks with lots of Error
creations, you may consider setting this to false If set to false, all
CallTraces in Error will be nil

#### func  Fatal

```go
func Fatal(err error, exitcode int)
```
Fatal prints the given err to stderr and exits immediately with the given exit
code

#### func  Fatalln

```go
func Fatalln(err error, exitcode int)
```
Fatalln prints the given err to stderr followed by a newline and exits
immediately with the given exit code

#### func  Print

```go
func Print(err error)
```
Print prints the given err to stderr

#### func  Println

```go
func Println(err error)
```
Println prints the given err to stderr followed by a newline

#### type CallTrace

```go
type CallTrace struct {
}
```

CallTrace represents a call stack trace similar to Java's stack trace

#### func  Trace

```go
func Trace(skip int) *CallTrace
```
Trace returns a new CallTrace starting from this call Use skip to skip the first
entries in the trace

#### func (*CallTrace) String

```go
func (ct *CallTrace) String() string
```

#### type ErrTmpl

```go
type ErrTmpl struct {
}
```

ErrTmpl is an error template to define equalities between different errors

#### func  NewErrTmpl

```go
func NewErrTmpl(name, format string) *ErrTmpl
```
NewErrTmpl returns a new error template with the given format string as a
predefined error message

#### func (*ErrTmpl) Error

```go
func (t *ErrTmpl) Error() string
```
Error implementation just for satisfying the error interface Please dont use
ErrTmpls as actual errors

#### func (*ErrTmpl) New

```go
func (t *ErrTmpl) New(args ...interface{}) *Error
```
New returns a new Error in which the given values are being formatted into the
format string of its template

#### type Error

```go
type Error struct {
}
```

Error is a wrapper for error with stack trace

#### func  New

```go
func New(msg string) *Error
```
New returns a new Error with the given message

#### func  Wrap

```go
func Wrap(msg string, cause error) *Error
```
Wrap returns a new Error with the given message which is caused by cause

#### func (*Error) Error

```go
func (e *Error) Error() string
```

#### func (*Error) Is

```go
func (e *Error) Is(target error) bool
```
Is implements the error equality function used by errors.Is() It returns true if
the error is the same instance or is created using the same ErrTmpl

#### func (*Error) Unwrap

```go
func (e *Error) Unwrap() error
```