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.

Constructors

this this(Set set): Undocumented in source.

Postblit

this(this) this(this): Undocumented in source.

Members

Aliases

Set alias Set = MapSet!(A, V, nullValue): Underlying MapSet.

Functions

copy void copy(A source, A target): Algorithm interface - copy a value target another name, without resolving it (unless it's already resolved).
dup MapSetVisitor dup(): Undocumented in source. Be warned that the author may not have intended to support it.
get V get(A name): Algorithm interface - get a value by name
getAll const(V)[] getAll(A name): Get all possible values for this variable at this point. Should be used mainly for debugging.
inject void inject(A name, V[] values): Inject a variable and values to iterate over. The variable must not have been resolved yet.
injectiveTransform void injectiveTransform(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). The function is assumed to be injective (does not produce duplicate outputs for distinct inputs).
multiTransform void multiTransform(A[] inputs, A[] outputs, void delegate(scope V[] inputValues, scope V[] outputValues) fun): Perform a transformation with multiple inputs and outputs. Inputs and outputs must not overlap. Can be used to perform binary operations, copy-transforms, and more.
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)).
targetTransform void targetTransform(A input, A output, void delegate(ref const V inputValue, out V outputValue) fun): Perform a transformation with one input and one output. Does not reorder the MapSet.
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).

Properties

currentSubset Set currentSubset [@property getter]: Peek at the subset the algorithm is currently working with.

Structs

Var struct Var: Internal state.
VarState struct VarState
initialVarState VarState[A] initialVarState;: Undocumented in source.

Variables

set Set set;: Underlying MapSet.
stack Var[] stack;: Undocumented in source.
stackPos size_t stackPos;: Undocumented in source.
varState VarState[A] varState;: 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);