vartypes

Documentation

Overview

Package vartypes contains basic types for manipulating Elvish variables.

Index

• func DelElement(variable Variable, indicies []interface{}) error
• func GetElementErrorLevel(err error) int
• func IsBlackhole(v Variable) bool
• type Variable
  • func GetHeadOfElement(v Variable) Variable
  • func MakeElement(v Variable, indicies []interface{}) (Variable, error)
  • func NewAny(v interface{}) Variable
  • func NewBlackhole() Variable
  • func NewCallback(set func(interface{}) error, get func() interface{}) Variable
  • func NewElement(v Variable, a []interface{}, i []interface{}) Variable
  • func NewEnv(name string) Variable
  • func NewRo(v interface{}) Variable
  • func NewRoCallback(get func() interface{}) Variable

Functions

func DelElement

func DelElement(variable Variable, indicies []interface{}) error

DelElement deletes an element. It uses a similar process to MakeElement, except that the last level of container needs to be Dissoc-able instead of Assoc-able.

func GetElementErrorLevel

func GetElementErrorLevel(err error) int

GetElementErrorLevel returns the level of an error returned by MakeElement or DelElement. Level 0 represents that the error is about the variable itself. If the argument was not returned from MakeVariable, -1 is returned.

func IsBlackhole

func IsBlackhole(v Variable) bool

IsBlackhole returns whether the variable is a blackhole variable.

Types

type Variable

type Variable interface {
	Set(v interface{}) error
	Get() interface{}
}

Variable represents an Elvish variable.

func GetHeadOfElement

func GetHeadOfElement(v Variable) Variable

GetHeadOfElement gets the underlying head variable of an element variable, or nil if the argument is not an element variable.

func MakeElement

func MakeElement(v Variable, indicies []interface{}) (Variable, error)

MakeElement returns a variable, that when set, simulates the mutation of an element.

func NewAny

func NewAny(v interface{}) Variable

NewAny creates a variable with an initial value. The variable created can be assigned values of any type.

func NewBlackhole

func NewBlackhole() Variable

NewBlackhole returns a blackhole variable. Assignments to a blackhole variable will be discarded, and getting a blackhole variable always returns an empty string.

func NewCallback

func NewCallback(set func(interface{}) error, get func() interface{}) Variable

NewCallback makes a variable from a set callback and a get callback.

func NewElement

func NewElement(v Variable, a []interface{}, i []interface{}) Variable

NewElement returns an ephemeral variable used for assigning variable element.

func NewEnv

func NewEnv(name string) Variable

NewEnv returns an environment variable.

func NewRo

func NewRo(v interface{}) Variable

func NewRoCallback

func NewRoCallback(get func() interface{}) Variable

NewRoCallback makes a read-only variable from a get callback.