Documentation
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Overview ¶
Package tuple provides a layer for encoding and decoding multi-element tuples into keys usable by FoundationDB. The encoded key maintains the same sort order as the original tuple: sorted first by the first element, then by the second element, etc. This makes the tuple layer ideal for building a variety of higher-level data models.
For general guidance on tuple usage, see the Tuple section of Data Modeling (https://foundationdb.com/documentation/data-modeling.html#data-modeling-tuples).
FoundationDB tuples can currently encode byte and unicode strings, integers and NULL values. In Go these are represented as []byte, string, int64 and nil.
Index ¶
Constants ¶
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Variables ¶
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Functions ¶
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Types ¶
type Element ¶
type Element interface{}
A Element is one of the types that may be encoded in FoundationDB tuples. Although the Go compiler cannot enforce this, it is a programming error to use an unsupported types as a Element (and will typically result in a runtime panic).
The valid types for Element are []byte (or lex.KeyConvertible), string, int64 (or int), and nil.
type Tuple ¶
type Tuple []Element
Tuple is a slice of objects that can be encoded as FoundationDB tuples. If any of the Elements are of unsupported types, a runtime panic will occur when the Tuple is packed.
Given a Tuple T containing objects only of these types, then T will be identical to the Tuple returned by unpacking the byte slice obtained by packing T (modulo type normalization to []byte and int64).
func Unpack ¶
Unpack returns the tuple encoded by the provided byte slice, or an error if the key does not correctly encode a FoundationDB tuple.
func (Tuple) LexKey ¶
func (t Tuple) LexKey() lex.Key
LexKey returns the packed representation of a Tuple, and allows Tuple to satisfy the lex.KeyConvertible interface. LexKey will panic in the same circumstances as Pack.
func (Tuple) LexRangeKeySelectors ¶
func (t Tuple) LexRangeKeySelectors() (lex.Selectable, lex.Selectable)
LexRangeKeySelectors allows Tuple to satisfy the lex.Range interface. The range represents all keys that encode tuples strictly starting with a Tuple (that is, all tuples of greater length than the Tuple of which the Tuple is a prefix).
func (Tuple) LexRangeKeys ¶
func (t Tuple) LexRangeKeys() (lex.KeyConvertible, lex.KeyConvertible)
LexRangeKeys allows Tuple to satisfy the lex.ExactRange interface. The range represents all keys that encode tuples strictly starting with a Tuple (that is, all tuples of greater length than the Tuple of which the Tuple is a prefix).
func (Tuple) Pack ¶
Pack returns a new byte slice encoding the provided tuple. Pack will panic if the tuple contains an element of any type other than []byte, lex.KeyConvertible, string, int64, int or nil.
Tuple satisfies the lex.KeyConvertible interface, so it is not necessary to call Pack when using a Tuple with a FoundationDB API function that requires a key.
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