navigator

Documentation

Index

• type Navigator
  • func (n *Navigator[Key, Node, Context]) IdxKey() Key
  • func (n *Navigator[Key, Node, Context]) Pop() (node Node, ok bool)
  • func (n *Navigator[Key, Node, Context]) Seek(create bool, ctx Context) (next Node, ok bool)
  • func (n *Navigator[Key, Node, Context]) Trace(trace bool) *Navigator[Key, Node, Context]
• type Nexter
• type VoidContext

Types

type Navigator

type Navigator[Key any, Node Nexter[Key, Node, Context], Context any] struct {
	// Cur is current or cursor node.
	Cur Node

	// Idx of the next Key to navigate
	Idx int
	// Keys to Navigate
	Keys slice.Slice[Key]

	// TraceNodes causes Nodes to be populated during a Seek operation if true.
	TraceNodes bool
	// Nodes iterated over during a seek operation.
	Nodes slice.Slice[Node]
}

Navigator can move through graph like structures whose nodes fulfill Nexter.

func (*Navigator[Key, Node, Context]) IdxKey

func (n *Navigator[Key, Node, Context]) IdxKey() Key

IdxKey is a helper to get the key at the current index

func (*Navigator[Key, Node, Context]) Pop

func (n *Navigator[Key, Node, Context]) Pop() (node Node, ok bool)

Pop the last value in Nodes off and assign it to Cur. This requires that Nodes are populated. So in order to use this after a Seek operation, TraceNodes needs to be true prior to the seek operation.

func (*Navigator[Key, Node, Context]) Seek

func (n *Navigator[Key, Node, Context]) Seek(create bool, ctx Context) (next Node, ok bool)

Seek starts with the initial value of Cur and iterates through Keys calling Next for each key so long as the returned OK is true. If TraceNodes is true, the navigated nodes will be added to Nodes.

func (*Navigator[Key, Node, Context]) Trace

func (n *Navigator[Key, Node, Context]) Trace(trace bool) *Navigator[Key, Node, Context]

Trace is a chainable helper. It sets TraceNodes to trace and returns the Navigator.

type Nexter

type Nexter[Key, Node, Context any] interface {
	Next(key Key, create bool, ctx Context) (Node, bool)
}

Nexter represents a node structure that can get the next node based on the key. If "create" is true, the Next method should create the node if it does not exist. Context allows arbitrary additional information to be passed in that may be necessary to perform the Next operation.

type VoidContext

type VoidContext struct{}

VoidContext is provided as a helper for instances where Context is not necessary.

var Void VoidContext

Void is an instance of VoidContext