value

Documentation

Index

• Variables
• type EmptyConstructor
  • func StringEnum(choices ...string) EmptyConstructor
• type TypeInfo
• type Value
  • func Bool() (Value, error)
  • func Duration() (Value, error)
  • func Int() (Value, error)
  • func IntSlice() (Value, error)
  • func Path() (Value, error)
  • func PathSlice() (Value, error)
  • func String() (Value, error)
  • func StringSlice() (Value, error)

Variables

var ErrIncompatibleInterface = errors.New("could not decode interface into Value")

Types

type EmptyConstructor

type EmptyConstructor = func() (Value, error)

EmptyConstructur just builds a new value. Useful to create new values as well as initialize them

func StringEnum

func StringEnum(choices ...string) EmptyConstructor

StringEnum acts just like a string, except it only lets the user update from the choices provided when creating the EmptyConstructor for it.

type TypeInfo

type TypeInfo int64

const (
	TypeInfoScalar TypeInfo = iota + 1
	TypeInfoSlice
	TypeInfoMap
)

These constants describe the container type of a Value.

type Value

type Value interface {

	// Description of the type. useful for help messages. Should not be used as an ID.
	Description() string

	// Get returns the underlying value. It's meant to be type asserted against
	// Example: myInt := v.(int)
	Get() interface{}

	// ReplaceFromInterface replaces a value with one found in an interface.
	// Useful to update a Value from a config.
	ReplaceFromInterface(interface{}) error

	// String returns a string ready to be printed!
	String() string

	// StringSlice returns a []string ready to be printed for slice values and nil for others
	StringSlice() []string

	// TypeInfo specifies whether what "overall" type of value this is - scalar, slice, etc.
	TypeInfo() TypeInfo

	// Update appends to container type Values from a string (useful for CLI flags, env vars, default values)
	// and replaces scalar Values
	Update(string) error

	// UpdateFromInterface updates a container type Value from an interface (useful for configs)
	// and replaces scalar values (for scalar values, UpdateFromInterface is the same as ReplaceFromInterface).
	// Note that UpdateFromInterface must be called with the "contained" type for container type Values
	// For example, the StringSlice.UpdateFromInterface
	// must be called with a string, not a []string
	// It returns ErrIncompatibleInterface if the interface can't be decoded
	UpdateFromInterface(interface{}) error
}

Value is a "generic" type to store different types into flags Inspired by https://golang.org/src/flag/flag.go . There are two underlying "type" families designed to fit in Value: scalar types (Int, String, ...) and container types (IntSlice, StringMap, ...).

func Bool

func Bool() (Value, error)

Bool is updated from "true" or "false"

func Duration

func Duration() (Value, error)

Duration is updateable from a string parsed with https://pkg.go.dev/time#ParseDuration

func Int

func Int() (Value, error)

Int is updateable from a float or int. If a float is passed, it will be truncated. Example: 4.5 -> 4, 3.99 -> 3

func IntSlice

func IntSlice() (Value, error)

IntSlice is updateable from a float or int. If a float is passed, it will be truncated. Example: 4.5 -> 4, 3.99 -> 3

func Path

func Path() (Value, error)

Path autoexpands ~ when updated and otherwise behaves like a string

func PathSlice

func PathSlice() (Value, error)

PathSlice autoexpands ~ when updated and otherwise behaves like a []string

func String

func String() (Value, error)

String accepts a string from a user. Pretty self explanatory.

func StringSlice

func StringSlice() (Value, error)

StringSlice accepts a string from a user and adds it to a slice. Pretty self explanatory.