MapSetVisitor

Allows executing a deterministic algorithm over all states in a given MapSet. If a variable is not queried by the algorithm, states for all variations of that variable are processed in one iteration.

static if(__VERSION__ >= 2083)

struct MapSetVisitor (

) {

alias Set = MapSet!(A, V);

Set set;

struct Var;

Var[] stack;

V[A] singularValues;

V[A] resolvedValues;

void put(A name, V value);

void transform(A name, void delegate(ref V value) fun);

}

Constructors

this this(Set set): Undocumented in source.

Members

Aliases

Set alias Set = MapSet!(A, V): Undocumented in source.

Functions

get V get(A name): Algorithm interface - get a value by name
next bool next(): Returns true if there are more states to iterate over, otherwise returns false
put void put(A name, V value): Algorithm interface - set a value by name
reset void reset(): Resets iteration to the beginning. Equivalent to but faster than constructing a new MapSetVisitor instance (visitor = MapSetVisitor(visitor.set)).
transform void transform(A name, void delegate(ref V value) fun): Apply a function over every possible value of the given variable, without resolving it (unless it's already resolved).

Structs

Var struct Var: Undocumented in source.

Variables

currentSubset Set currentSubset;
resolvedValues V[A] resolvedValues;: Undocumented in source.
set Set set;: Undocumented in source.
singularValues V[A] singularValues;: Undocumented in source.
stack Var[] stack;: Undocumented in source.

Examples

An algorithm which divides two numbers. When the divisor is zero, we don't even query the dividend, therefore processing all dividends in one iteration.

alias M = MapSet!(string, int);
M m = M.unitSet
	.cartesianProduct("divisor" , [0, 1, 2])
	.cartesianProduct("dividend", [0, 1, 2]);
assert(m.count == 9);

auto v = MapSetVisitor!(string, int)(m);
M results;
int iterations;
while (v.next())
{
	iterations++;
	auto divisor = v.get("divisor");
	if (divisor == 0)
		continue;
	auto dividend = v.get("dividend");
	v.put("quotient", dividend / divisor);
	results = results.merge(v.currentSubset);
}

assert(iterations == 7); // 1 for division by zero + 3 for division by one + 3 for division by two
assert(results.get("divisor", 2).get("dividend", 2).all("quotient") == [1]);
assert(results.get("divisor", 0).count == 0);