traverse

Documentation

Overview

Package traverse provides merkledag traversal functions

Index

• func Traverse(root node.Node, o Options) error
• type ErrFunc
• type Func
• type Options
• type Order
• type State

Functions

func Traverse

func Traverse(root node.Node, o Options) error

Types

type ErrFunc

type ErrFunc func(err error) error

If there is a problem walking to the Node, and ErrFunc is provided, Traverse will call ErrFunc with the error encountered. ErrFunc can decide how to handle that error, and return an error back to Traversal with how to proceed:

• nil - skip the Node and its children, but continue processing
• all other errors halt processing immediately.

If ErrFunc is nil, Traversal will stop, as if:

opts.ErrFunc = func(err error) { return err }

type Func

type Func func(current State) error

Func is the type of the function called for each dag.Node visited by Traverse. The traversal argument contains the current traversal state. If an error is returned, processing stops.

type Options

type Options struct {
	DAG     node.NodeGetter // the dagservice to fetch nodes
	Order   Order           // what order to traverse in
	Func    Func            // the function to perform at each step
	ErrFunc ErrFunc         // see ErrFunc. Optional

	SkipDuplicates bool // whether to skip duplicate nodes
}

Options specifies a series of traversal options

type Order

type Order int

Order is an identifier for traversal algorithm orders

const (
	DFSPre  Order = iota // depth-first pre-order
	DFSPost              // depth-first post-order
	BFS                  // breadth-first
)

type State

type State struct {
	Node  node.Node
	Depth int
}

State is a current traversal state