iterator

Documentation

Overview

Package iterator provides functions to work with Neo iterators.

Index

• func Key(it Iterator) interface{}
• func Keys(it Iterator) enumerator.Enumerator
• func Next(it Iterator) bool
• func Value(it Iterator) interface{}
• func Values(it Iterator) enumerator.Enumerator
• type Iterator
  • func Concat(a, b Iterator) Iterator
  • func Create(items interface{}) Iterator

Functions

func Key

func Key(it Iterator) interface{}

Key returns iterator's key at current position. It's only valid to call after successful Next call. This function uses `System.Iterator.Key` syscall.

func Keys

func Keys(it Iterator) enumerator.Enumerator

Keys returns Enumerator ranging over keys or the given Iterator. Note that this Enumerator is actually directly tied to the underlying Iterator, so that advancing it with Next will actually advance the Iterator too. This function uses `System.Iterator.Keys` syscall.

func Next

func Next(it Iterator) bool

Next advances the iterator returning true if it is was successful (and you can use Key or Value) and false otherwise (and there are no more elements in this Iterator). This function uses `System.Enumerator.Next` syscall.

func Value

func Value(it Iterator) interface{}

Value returns iterator's current value. It's only valid to call after successful Next call. This function uses `System.Enumerator.Value` syscall.

func Values

func Values(it Iterator) enumerator.Enumerator

Values returns Enumerator ranging over values or the given Iterator. Note that this Enumerator is actually directly tied to the underlying Iterator, so that advancing it with Next will actually advance the Iterator too. This function uses `System.Iterator.Values` syscall.

Types

type Iterator

type Iterator struct{}

Iterator represents a Neo iterator, it's an opaque data structure that can be properly created by Create or storage.Find. Unlike enumerators, iterators range over key-value pairs, so it's convenient to use them for maps. This structure is similar in function to Neo .net framework's Iterator.

func Concat

func Concat(a, b Iterator) Iterator

Concat concatenates two given iterators returning one that will range on a first and then continue with b. Iterator positions are not reset for a and b, so if any of them was already advanced by Next the resulting Iterator will point at this new position and never go back to previous key-value pairs. Concatenated iterators also remain completely independent in results they return, so if both contain the same key you'll receive this key twice when iterating. This function uses `System.Iterator.Concat` syscall.

func Create

func Create(items interface{}) Iterator

Create creates an iterator from the given items (array, struct, map, byte array or integer and boolean converted to byte array). A new iterator is set to point at element -1, so to access its first element you need to call Next first. This function uses `System.Iterator.Create` syscall.