README
¶
but
Just a few utilities for error management
Why? It's called but because a but is an and with a non-standard expectation
How? You can create error templates as string constants (see but.Note) and format them later. You can exit with/out codes if templates are filled, errors are nil and predicates are satisfied
package but // import "github.com/kendfss/but"
// VARIABLES
var Separator rune = '=' // used by Must to separate output
// FUNCTIONS
func As(err error, target any) bool
// As finds the first error in err's chain that matches target, and if one
// is found, sets target to that error value and returns true. Otherwise,
// it returns false.
func Exif(pred bool, fmtArgs ...any)
// Exif calls os.Exit if pred == true, which implies err != nil see go doc but
// FmtArgs for more info
func Exit(code int, fmtArgs ...any)
// Exif calls os.Exit and, optionally, logs a message to the output see go doc
// but FmtArgs for more info
func Fmt(format string) func(...any) error
// Create a template for errors using a format string see go doc but FmtArgs
// for more info
func GetOutput() io.Writer
// SetOutput acquires the io.Writer to which all logs are made
func HaveNeedc[T comparable](have, want T) error
// HaveNeedf produces "want, have" error if the two values are not equal nil
// otherwise see go doc but Template for more general use cases
func HaveNeedf[T any](eq func(T, T) bool, have, want T) error
// HaveNeedf produces "want, have" error see go doc but Template for more
// general use cases
func HaveWant(have, want any) error
// HaveWant produces "want, have" error in cases where difference is already
// known see go doc but Template for more general use cases
func Is(err, target error) bool
// Is reports whether any error in err's chain matches target.
func Join(errs ...error) error
// Join returns an error that wraps the given errors. Any nil error values are
// discarded. Join returns nil if errs contains no non-nil values. The error
// formats as the concatenation of the strings obtained by calling the Error
// method of each element of errs, with a newline between each string.
func LST(arg string) bool
// LST checks if a string is line-separator-terminated
func Must(err error, fmtArgs ...any)
// panic if an error is not nil see go doc but FmtArgs for more info
func MustBool(pred bool, fmtArgs ...any)
// panic if an error is not nil see go doc but FmtArgs for more info
func Mustv[T any](val T, err error, fmtArgs ...any) T
// Mustv unpacks the return value of a function that might fail panicking if it
// does
// Mustv(myfunc(...))
// see go doc but FmtArgs for more info
func Mustv2[I, O any](fn func(I) (O, error), fmtArgs ...any) func(I) O
// see go doc but FmtArgs for more info
func New(msg string, fmtArgs ...any) error
// Error is a errors.New && fmt.Errorf hybrid. returns nil if text is empty
// string seen go doc but FmtArgs for more info
func ParseArgs(args ...any) (code *int, msg *string, rem []any)
// ParseArgs parses an []any in accordance with the FmtArgs constraint see go
// doc but FmtArgs for more info
func SetOutput[T Writer](dst T)
// SetOutput configures the io.Writer to which all logs are made
func Should(pred bool, fmtArgs ...any) bool
// print a non-nil error to stderr return false if err != nil see go doc but
// FmtArgs for more info
func Strr(arg any) string
func Strrf(arg any, format string) string
// Strrf checks if arg is a stringer, error, or string, and returns:
// the associated string
// else a representation (if format != "") else ""
func Unwrap(err error) error
// Unwrap returns the result of calling the Unwrap method on err, if err's type
// contains an Unwrap method returning error. Otherwise, Unwrap returns nil.
// Unwrap returns nil if the Unwrap method returns []error.
// TYPES
type FmtArgs interface {
int | string | []any
} // Fmt functions expect trailing arguments to have one of the above types
type Note string // error message
func NewNote(fmtArgs ...any) Note
// Create new notes see go doc but FmtArgs for more info
func (n Note) Appendf(form, sep string, args ...any) Note
// Appendf concatenates n with the given args using the given %-form and sep
func (n Note) Error() string
func (n Note) Exif(code int, fmtArgs ...any)
// Exif much like exit, except that it will only exit if the underlying string
// is empty accepts format parameters as described in the but.FmtArgs interface
func (n Note) Exit(code int)
// Exit the entire program with the given code exits with 0 if the Note is
// empty if you only want to exit on non-nil errors, use Exif
func (n Note) Fmt(args ...any) Note
func (n Note) String() string
type Writer interface {
io.Writer
io.StringWriter
}
// Writer is the type needed to log to std{in,err,out} and files
Documentation
¶
Index ¶
- Variables
- func As(err error, target any) bool
- func Exif(pred bool, fmtArgs ...any)
- func Exit(code int, fmtArgs ...any)
- func Fmt(format string) func(...any) error
- func GetOutput() io.Writer
- func HaveNeedc[T comparable](have, want T) error
- func HaveNeedf[T any](eq func(T, T) bool, have, want T) error
- func HaveWant(have, want any) error
- func Is(err, target error) bool
- func Join(errs ...error) error
- func LST(arg string) bool
- func Must(err error, fmtArgs ...any)
- func MustBool(pred bool, fmtArgs ...any)
- func Mustv[T any](val T, err error, fmtArgs ...any) T
- func Mustv2[I, O any](fn func(I) (O, error), fmtArgs ...any) func(I) O
- func New(msg string, fmtArgs ...any) error
- func ParseArgs(args ...any) (code *int, msg *string, rem []any)
- func SetOutput[T Writer](dst T)
- func Should(err error) bool
- func ShouldBool(pred bool, fmtArgs ...any) bool
- func Strr(arg any) string
- func Strrf(arg any, format string) string
- func Unwrap(err error) error
- type FmtArgs
- type Note
- type Writer
Constants ¶
This section is empty.
Variables ¶
var Separator rune = '=' // used by Must to separate output
Functions ¶
func As ¶
As finds the first error in err's chain that matches target, and if one is found, sets target to that error value and returns true. Otherwise, it returns false.
func Exif ¶
Exif calls os.Exit if pred == true, which implies err != nil see go doc but FmtArgs for more info
func Exit ¶
Exif calls os.Exit and, optionally, logs a message to the output see go doc but FmtArgs for more info
func HaveNeedc ¶
func HaveNeedc[T comparable](have, want T) error
HaveNeedf produces "want, have" error if the two values are not equal nil otherwise see go doc but Template for more general use cases
func HaveNeedf ¶
HaveNeedf produces "want, have" error see go doc but Template for more general use cases
func HaveWant ¶
HaveWant produces "want, have" error in cases where difference is already known see go doc but Template for more general use cases
func Join ¶
Join returns an error that wraps the given errors. Any nil error values are discarded. Join returns nil if errs contains no non-nil values. The error formats as the concatenation of the strings obtained by calling the Error method of each element of errs, with a newline between each string.
func Mustv ¶
Mustv unpacks the return value of a function that might fail panicking if it does
Mustv(myfunc(...))
see go doc but FmtArgs for more info
func New ¶
Error is a errors.New && fmt.Errorf hybrid. returns nil if text is empty string seen go doc but FmtArgs for more info
func ParseArgs ¶
ParseArgs parses an []any in accordance with the FmtArgs constraint see go doc but FmtArgs for more info
func SetOutput ¶
func SetOutput[T Writer](dst T)
SetOutput configures the io.Writer to which all logs are made
func ShouldBool ¶ added in v1.0.1
prints to stderr if pred is true see go doc but FmtArgs for more info
Types ¶
type Note ¶
type Note string
func (Note) Exif ¶
Exif much like exit, except that it will only exit if the underlying string is empty accepts format parameters as described in the but.FmtArgs interface
Source Files