Struct Cursor

Source

pub struct Cursor { /* private fields */ }

Expand description

A checked retained position for consumer progress.

§Examples

use automation_structures::Cursor;

let mut cursor = Cursor::new(2);
cursor.advance_to(5)?;
assert_eq!(cursor.position(), 5);

Implementations§

Source §

impl Cursor

Source

pub fn new(position: usize) -> Self

Construct a cursor at position.

Examples found in repository ?

examples/catalog.rs (line 135)

21fn main() -> Result<(), Box<dyn Error>> {
22    // Primitives.
23    let mut budget = Budget::new(8);
24    assert!(budget.try_reserve(3));
25    budget.commit_reservation(3)?;
26
27    let mut hierarchy = QualityHierarchy::new(2, 2);
28    hierarchy.set_node_properties(0, 2, 1)?;
29    hierarchy.set_node_properties(1, 1, 2)?;
30    hierarchy.add_child(0, 1)?;
31
32    let mut registry = ResourceRegistry::new();
33    registry.insert(1, 10);
34    assert_eq!(registry.get(1), Some(10));
35
36    let mut hard = CompetitiveSelectionHard::new(2)?;
37    hard.update_score(0, 2)?;
38    hard.update_score(1, 1)?;
39    assert_eq!(hard.evaluate(), 0);
40
41    let mut exclusive = CompetitiveSelectionHardExclusive::new(1, 2, 2)?;
42    exclusive.update_score(0, 0, 2)?;
43    exclusive.update_score(0, 1, 1)?;
44    assert_eq!(exclusive.evaluate(0)?, 0);
45
46    let mut soft = CompetitiveSelectionSoft::begin(vec![3, 1], 4, 3)?;
47    assert_eq!(soft.assign_next()?, 0);
48
49    let mut ranked = CompetitiveSelectionRanked::new(vec![2, 1], 1, 2)?;
50    ranked.select();
51    assert_eq!(ranked.is_selected(0), Some(true));
52
53    let mut actuation = ActuationPass::new(vec![Some(7)]);
54    actuation.actuate(0)?;
55    actuation.finish()?;
56
57    let mut propagation = PropagationPass::new(1, 2, vec![], vec![0])?;
58    propagation.start_round()?;
59    propagation.update_node(0)?;
60    propagation.end_round()?;
61
62    let mut convergence = ConvergenceGovernor::new(2, 6, 2, 10)?;
63    assert_eq!(convergence.update(1)?, 1);
64
65    let mut audit = AuditSink::new(1);
66    assert!(audit.try_record(7));
67    assert!(audit.validate());
68
69    let mut backtracking = BacktrackingTraversal::new(2, 1, 0)?;
70    backtracking.descend(1, 1)?;
71    backtracking.visit()?;
72
73    // Named compositions.
74    let mut snapshot = AllocationSnapshot::new(3, 1);
75    snapshot.accept(0, 3)?;
76
77    let mut federated = FederatedBudget::new(4, 1);
78    assert!(federated.try_delegate(0, 4));
79    assert!(federated.try_allocate(0, 2));
80
81    let mut bisection = Bisection::new(4, 2)?;
82    bisection.converge();
83    assert!(bisection.is_converged());
84
85    let mut classes = EquivalenceClass::new(2, 1);
86    assert!(classes.union(0, 1)?);
87
88    let mut rate_limit = RateLimit::new(1, 1, 1)?;
89    assert!(rate_limit.try_acquire());
90
91    let mut reduction = Reduction::new(vec![2, 3])?;
92    reduction.process_next()?;
93
94    let mut graph = RelationshipGraph::new(2, 1);
95    assert!(graph.add_edge(0, 1, 1)?);
96
97    let mut sampler = Sampler::new(vec![1, 1], 1);
98    sampler.sample(0)?;
99
100    let mut select_then_actuate = SelectThenActuate::new(1, 2)?;
101    select_then_actuate.update_score(0, 0, 1)?;
102    assert_eq!(select_then_actuate.evaluate(0)?, 0);
103    select_then_actuate.actuate(0)?;
104    select_then_actuate.finish()?;
105
106    let mut signal = Signal::new(0, 2, 1)?;
107    assert!(signal.set_value(1)?);
108    signal.notify(0)?;
109
110    let mut traversal = TraversalEngine::new(1, 0, 1)?;
111    traversal.visit(0)?;
112    traversal.terminate()?;
113
114    // Execution modalities.
115    let mut sequential = Sequential::new(1, 2, 0)?;
116    assert!(sequential.begin_step());
117    assert!(sequential.complete_step(1));
118
119    let mut fork_join = ForkJoin::new(1, 2, 0)?;
120    assert!(fork_join.start_worker(0));
121    assert!(fork_join.complete_worker(0, 1));
122    assert!(fork_join.barrier());
123    assert!(fork_join.produce_output());
124
125    let mut step_graph = StepGraph::new(1, vec![])?;
126    assert!(step_graph.start(0));
127    assert!(step_graph.complete(0));
128
129    let mut stream_graph = StreamGraph::new(3, 1, 1, 2)?;
130    assert!(stream_graph.ingest(1));
131    assert!(stream_graph.advance_first());
132    assert_eq!(stream_graph.consume(), Some(1));
133
134    // Connective roles.
135    let mut cursor = Cursor::new(0);
136    cursor.advance_to(1)?;
137
138    let mut accumulator = Accumulator::new(vec![1]);
139    assert_eq!(accumulator.advance(), Some(1));
140    assert_eq!(accumulator.accumulated(0), Some(1));
141
142    let mut marker = Marker::new(false);
143    assert!(marker.set());
144
145    let mut counter = Counter::new(0);
146    assert!(counter.try_increment());
147
148    let mut buffer = Buffer::new(1);
149    assert_eq!(buffer.push(1), Ok(()));
150    assert_eq!(buffer.pop(), Some(1));
151
152    assert!(projection_consistent(true, true));
153    assert!(strictly_before(0, 1));
154
155    assert_debuggable!(
156        budget,
157        hierarchy,
158        registry,
159        hard,
160        exclusive,
161        soft,
162        ranked,
163        actuation,
164        propagation,
165        convergence,
166        audit,
167        backtracking,
168        snapshot,
169        federated,
170        bisection,
171        classes,
172        rate_limit,
173        reduction,
174        graph,
175        sampler,
176        select_then_actuate,
177        signal,
178        traversal,
179        sequential,
180        fork_join,
181        step_graph,
182        stream_graph,
183        cursor,
184        accumulator,
185        marker,
186        counter,
187        buffer,
188    );
189
190    println!("all public automation structures constructed and exercised");
191    Ok(())
192}

Source

pub fn position(&self) -> usize

Read the retained position.

Source

pub fn advance_to(&mut self, position: usize) -> Result<(), CursorError>

Move monotonically to position.

§Errors

Returns CursorError::Regression when position precedes the retained position.

Examples found in repository ?

examples/catalog.rs (line 136)

21fn main() -> Result<(), Box<dyn Error>> {
22    // Primitives.
23    let mut budget = Budget::new(8);
24    assert!(budget.try_reserve(3));
25    budget.commit_reservation(3)?;
26
27    let mut hierarchy = QualityHierarchy::new(2, 2);
28    hierarchy.set_node_properties(0, 2, 1)?;
29    hierarchy.set_node_properties(1, 1, 2)?;
30    hierarchy.add_child(0, 1)?;
31
32    let mut registry = ResourceRegistry::new();
33    registry.insert(1, 10);
34    assert_eq!(registry.get(1), Some(10));
35
36    let mut hard = CompetitiveSelectionHard::new(2)?;
37    hard.update_score(0, 2)?;
38    hard.update_score(1, 1)?;
39    assert_eq!(hard.evaluate(), 0);
40
41    let mut exclusive = CompetitiveSelectionHardExclusive::new(1, 2, 2)?;
42    exclusive.update_score(0, 0, 2)?;
43    exclusive.update_score(0, 1, 1)?;
44    assert_eq!(exclusive.evaluate(0)?, 0);
45
46    let mut soft = CompetitiveSelectionSoft::begin(vec![3, 1], 4, 3)?;
47    assert_eq!(soft.assign_next()?, 0);
48
49    let mut ranked = CompetitiveSelectionRanked::new(vec![2, 1], 1, 2)?;
50    ranked.select();
51    assert_eq!(ranked.is_selected(0), Some(true));
52
53    let mut actuation = ActuationPass::new(vec![Some(7)]);
54    actuation.actuate(0)?;
55    actuation.finish()?;
56
57    let mut propagation = PropagationPass::new(1, 2, vec![], vec![0])?;
58    propagation.start_round()?;
59    propagation.update_node(0)?;
60    propagation.end_round()?;
61
62    let mut convergence = ConvergenceGovernor::new(2, 6, 2, 10)?;
63    assert_eq!(convergence.update(1)?, 1);
64
65    let mut audit = AuditSink::new(1);
66    assert!(audit.try_record(7));
67    assert!(audit.validate());
68
69    let mut backtracking = BacktrackingTraversal::new(2, 1, 0)?;
70    backtracking.descend(1, 1)?;
71    backtracking.visit()?;
72
73    // Named compositions.
74    let mut snapshot = AllocationSnapshot::new(3, 1);
75    snapshot.accept(0, 3)?;
76
77    let mut federated = FederatedBudget::new(4, 1);
78    assert!(federated.try_delegate(0, 4));
79    assert!(federated.try_allocate(0, 2));
80
81    let mut bisection = Bisection::new(4, 2)?;
82    bisection.converge();
83    assert!(bisection.is_converged());
84
85    let mut classes = EquivalenceClass::new(2, 1);
86    assert!(classes.union(0, 1)?);
87
88    let mut rate_limit = RateLimit::new(1, 1, 1)?;
89    assert!(rate_limit.try_acquire());
90
91    let mut reduction = Reduction::new(vec![2, 3])?;
92    reduction.process_next()?;
93
94    let mut graph = RelationshipGraph::new(2, 1);
95    assert!(graph.add_edge(0, 1, 1)?);
96
97    let mut sampler = Sampler::new(vec![1, 1], 1);
98    sampler.sample(0)?;
99
100    let mut select_then_actuate = SelectThenActuate::new(1, 2)?;
101    select_then_actuate.update_score(0, 0, 1)?;
102    assert_eq!(select_then_actuate.evaluate(0)?, 0);
103    select_then_actuate.actuate(0)?;
104    select_then_actuate.finish()?;
105
106    let mut signal = Signal::new(0, 2, 1)?;
107    assert!(signal.set_value(1)?);
108    signal.notify(0)?;
109
110    let mut traversal = TraversalEngine::new(1, 0, 1)?;
111    traversal.visit(0)?;
112    traversal.terminate()?;
113
114    // Execution modalities.
115    let mut sequential = Sequential::new(1, 2, 0)?;
116    assert!(sequential.begin_step());
117    assert!(sequential.complete_step(1));
118
119    let mut fork_join = ForkJoin::new(1, 2, 0)?;
120    assert!(fork_join.start_worker(0));
121    assert!(fork_join.complete_worker(0, 1));
122    assert!(fork_join.barrier());
123    assert!(fork_join.produce_output());
124
125    let mut step_graph = StepGraph::new(1, vec![])?;
126    assert!(step_graph.start(0));
127    assert!(step_graph.complete(0));
128
129    let mut stream_graph = StreamGraph::new(3, 1, 1, 2)?;
130    assert!(stream_graph.ingest(1));
131    assert!(stream_graph.advance_first());
132    assert_eq!(stream_graph.consume(), Some(1));
133
134    // Connective roles.
135    let mut cursor = Cursor::new(0);
136    cursor.advance_to(1)?;
137
138    let mut accumulator = Accumulator::new(vec![1]);
139    assert_eq!(accumulator.advance(), Some(1));
140    assert_eq!(accumulator.accumulated(0), Some(1));
141
142    let mut marker = Marker::new(false);
143    assert!(marker.set());
144
145    let mut counter = Counter::new(0);
146    assert!(counter.try_increment());
147
148    let mut buffer = Buffer::new(1);
149    assert_eq!(buffer.push(1), Ok(()));
150    assert_eq!(buffer.pop(), Some(1));
151
152    assert!(projection_consistent(true, true));
153    assert!(strictly_before(0, 1));
154
155    assert_debuggable!(
156        budget,
157        hierarchy,
158        registry,
159        hard,
160        exclusive,
161        soft,
162        ranked,
163        actuation,
164        propagation,
165        convergence,
166        audit,
167        backtracking,
168        snapshot,
169        federated,
170        bisection,
171        classes,
172        rate_limit,
173        reduction,
174        graph,
175        sampler,
176        select_then_actuate,
177        signal,
178        traversal,
179        sequential,
180        fork_join,
181        step_graph,
182        stream_graph,
183        cursor,
184        accumulator,
185        marker,
186        counter,
187        buffer,
188    );
189
190    println!("all public automation structures constructed and exercised");
191    Ok(())
192}