a11::flow::Value Class Reference

One Flow value. More...

#include <cpp/a11/flow/values.h>

Public Types
enum class	Kind {   kNull , kBool , kInteger , kDouble ,   kString , kBytes , kList , kObject ,   kDuration , kTime , kChunk , kHost }
using	Pairs = std::vector< std::pair< std::string, Value > >
	The pairs of an object, in the order they were written.

Public Member Functions
	Value ()=default
Kind	kind () const
bool	IsNull () const
bool	IsNumber () const
bool	IsTimelike () const
bool	IsTextlike () const
	Whether the value is one the language itself can take apart: a string or a byte string, which index and slice but are not containers of values.
bool	boolean () const
std::int64_t	integer () const
double	number () const
const std::string &	text () const
const std::vector< Value > &	items () const
const Pairs &	pairs () const
absl::Duration	duration () const
absl::Time	time () const
const data::Chunk &	chunk () const
const HostObject &	host () const
const std::shared_ptr< const HostObject > &	host_object () const
const Value *absl_nullable	Get (std::string_view key) const
	The value at key of an object, or nullptr.

Static Public Member Functions
static Value	Null ()
static Value	Bool (bool value)
static Value	Integer (std::int64_t value)
static Value	Double (double value)
static Value	String (std::string value)
static Value	Bytes (data::Bytes value)
static Value	List (std::vector< Value > items)
static Value	Object (Pairs pairs)
static Value	Duration (absl::Duration value)
static Value	Time (absl::Time value)
static Value	Chunk (data::Chunk chunk)
static Value	Host (std::shared_ptr< const HostObject > object)
static Value	Of (const syntax::Constant &constant)
	The value a Constant – a literal, or a folded literal expression – is.

Friends
bool	operator== (const Value &left, const Value &right)
	Whether the two values are equal, as == in a flow decides it.

Detailed Description

One Flow value.

Immutable and cheap to copy: a container is held behind a shared_ptr, so an item read once and handed to eight readers is one allocation, not eight. Integers are kept apart from doubles because the language's own output depends on it – text 3 is "3" and text 3.0 is "3.0", exactly as the Python reference rendered them – and because a count of values has to be a whole number of them.

Member Typedef Documentation

Pairs

using a11::flow::Value::Pairs = std::vector<std::pair<std::string, Value> >

The pairs of an object, in the order they were written.

A vector rather than a hash map: a flow's objects have a handful of keys, insertion order is what a value written back out should keep, and a linear scan over five entries beats hashing them.

Member Enumeration Documentation

Kind

enum class a11::flow::Value::Kind

strong

Enumerator
kNull	A value that is not there: an absent key, an empty stream, a missing header. One kind for all of them, because a flow asking if not x should not have to know which sort of nothing it got.
kBool
kInteger
kDouble
kString
kBytes
kList
kObject
kDuration
kTime
kChunk	An undecoded chunk, kept whole so a pipe that only moves values re-writes the producer's own bytes and mimetype.
kHost

Constructor & Destructor Documentation

Value()

a11::flow::Value::Value ( )

default

Member Function Documentation

Bool()

Value a11::flow::Value::Bool ( bool  value )

static

boolean()

bool a11::flow::Value::boolean ( ) const

inline

Bytes()

Value a11::flow::Value::Bytes ( data::Bytes  value )

static

chunk()

const data::Chunk & a11::flow::Value::chunk ( ) const

inline

Chunk()

Value a11::flow::Value::Chunk ( data::Chunk  chunk )

static

Double()

Value a11::flow::Value::Double ( double  value )

static

duration()

absl::Duration a11::flow::Value::duration ( ) const

inline

Duration()

Value a11::flow::Value::Duration ( absl::Duration  value )

static

Get()

const Value *absl_nullable a11::flow::Value::Get

(

std::string_view

key

)

const

The value at key of an object, or nullptr.

host()

const HostObject & a11::flow::Value::host ( ) const

inline

Host()

Value a11::flow::Value::Host ( std::shared_ptr< const HostObject >  object )

static

host_object()

const std::shared_ptr< const HostObject > & a11::flow::Value::host_object ( ) const

inline

integer()

std::int64_t a11::flow::Value::integer ( ) const

inline

Integer()

Value a11::flow::Value::Integer ( std::int64_t  value )

static

IsNull()

bool a11::flow::Value::IsNull ( ) const

inline

IsNumber()

bool a11::flow::Value::IsNumber ( ) const

inline

IsTextlike()

bool a11::flow::Value::IsTextlike ( ) const

inline

Whether the value is one the language itself can take apart: a string or a byte string, which index and slice but are not containers of values.

IsTimelike()

bool a11::flow::Value::IsTimelike ( ) const

inline

items()

const std::vector< Value > & a11::flow::Value::items ( ) const

inline

kind()

Kind a11::flow::Value::kind ( ) const

inline

List()

Value a11::flow::Value::List ( std::vector< Value >  items )

static

Null()

static Value a11::flow::Value::Null ( )

inlinestatic

number()

double a11::flow::Value::number ( ) const

inline

Object()

Value a11::flow::Value::Object ( Pairs  pairs )

static

Of()

Value a11::flow::Value::Of ( const syntax::Constant &  constant )

static

The value a Constant – a literal, or a folded literal expression – is.

pairs()

const Pairs & a11::flow::Value::pairs ( ) const

inline

String()

Value a11::flow::Value::String ( std::string  value )

static

text()

const std::string & a11::flow::Value::text ( ) const

inline

time()

absl::Time a11::flow::Value::time ( ) const

inline

Time()

Value a11::flow::Value::Time ( absl::Time  value )

static

Friends And Related Symbol Documentation

operator==

bool operator== ( const Value &  left, const Value &  right  )

friend

Whether the two values are equal, as == in a flow decides it.

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The documentation for this class was generated from the following files:

• cpp/a11/flow/values.h
• cpp/a11/flow/values.cc