a11::flow::graph Namespace Reference

Classes
struct	Analysis
	Who reads and who writes each ref a body owns. More...
struct	Body
	A block of steps: a flow's top level, or a loop or branch body. More...
struct	Expr
	One resolved expression, and the streams it reads. More...
struct	FlowGraph
	The executable graph of one flow. More...
class	GraphBuilder
	Appends to a [FlowGraph] while the resolver walks a flow. More...
struct	LogTail
	One resolved pipeline stage. More...
struct	Ref
	One stream in the plan. More...
struct	Stage
struct	Step
	One resolved statement. More...

Typedefs
using	RefId = size_t
	Everything in a graph is named by index into the graph that owns it.
using	StepId = size_t
using	BodyId = size_t
using	ExprId = size_t

Enumerations
enum class	RefKind {   kFlowPort , kCallPort , kNode , kNodeId ,   kStatus , kHeader , kExpr , kDerived ,   kZip , kMerge , kWinner , kBound }
	What a stream in the plan is. More...
enum class	StepKind {   kCall , kPipe , kSkip , kWait ,   kDrain , kCancel , kAbort , kFail ,   kLog , kCapture , kForEach , kRepeat ,   kIf , kBlock }
	What a statement became. More...

Functions
std::string_view	StepKindName (StepKind kind)
Analysis	Analyse (const FlowGraph &flow, BodyId body)
	Work out who reads and writes what in one body.
bool	RecordsOutcome (StepKind kind)
	Whether a step records an outcome of its own for a name to read.

Variables
constexpr size_t	kNone = static_cast<size_t>(-1)
	No such thing – the absent id, for the many fields only some kinds use.

Typedef Documentation

BodyId

using a11::flow::graph::BodyId = typedef size_t

ExprId

using a11::flow::graph::ExprId = typedef size_t

RefId

using a11::flow::graph::RefId = typedef size_t

Everything in a graph is named by index into the graph that owns it.

Not pointers: the vectors grow while the graph is built, and a plan is handed across a language boundary and held for as long as a flow is registered. An index survives both.

StepId

using a11::flow::graph::StepId = typedef size_t

Enumeration Type Documentation

RefKind

enum class a11::flow::graph::RefKind

strong

What a stream in the plan is.

Enumerator
kFlowPort	A declared port of this flow.
kCallPort	A port of an action this flow calls: x.out.
kNode	A node of the flow's own: a stream it can write and read back.
kNodeId	A node's id, as one value – what a flow hands to an action that expects to be told where to write.
kStatus	The outcome of a call, a node, a port or a barrier, as a status record.
kHeader	One header of the call running this flow, as a single value.
kExpr	A stream of one value: an expression evaluated once.
kDerived	One stage applied to another stream.
kZip	Several streams read in step, as one stream of tuples: zip(a, b).
kMerge	Several streams read at once, as one stream of their values in the order they arrive: interleave(a, b).
kWinner	Which subject of a wait first of finished first, counted from zero, as one value. Produced by the barrier rather than read from anywhere, the way a status is produced by the thing it is the status of.
kBound	A stream the runtime binds per pass: a loop's value, its index, or a repeat's carry.

StepKind

enum class a11::flow::graph::StepKind

strong

What a statement became.

Enumerator
kCall
kPipe
kSkip
kWait
kDrain
kCancel
kAbort	abort node ..: end a node with a failure rather than with an end.
kFail
kLog
kCapture	Remember a stream's first value for the loop that owns this body: what <- and an until condition compile to.
kForEach
kRepeat
kIf
kBlock	[try] { ... }: a body run as one step, whose outcome is its own.

Function Documentation

Analyse()

Analysis a11::flow::graph::Analyse	(	const FlowGraph &	flow,
		BodyId	body
	)

Work out who reads and writes what in one body.

RecordsOutcome()

bool a11::flow::graph::RecordsOutcome ( StepKind  kind )

inline

Whether a step records an outcome of its own for a name to read.

The steps that run a nested body: what makes them different from a kCall is that their status is not a call's status to be asked for, it is theirs to have recorded. A name bound to one reads what it recorded, which is why s = try { .. } and done = for x in s { .. } are the same shape.

StepKindName()

std::string_view a11::flow::graph::StepKindName

(

StepKind

kind

)

Variable Documentation

kNone

constexpr size_t a11::flow::graph::kNone = static_cast<size_t>(-1)

inlineconstexpr

No such thing – the absent id, for the many fields only some kinds use.