WIP: PoC of meta strategy, which draws others by a given weight distribution

hypothesis-python/src/hypothesis/_strategies.py

@@ -2319,3 +2319,9 @@ def emails():
  return builds(u"{}@{}".format, local_part, domains()).filter(
  lambda addr: len(addr) <= 255
  )
+
+
+def distributed(strategies, weights):
+ # type: (List[SearchStrategy], List[Union[int, float]]) -> SearchStrategy[Any]
+ from hypothesis.provisional import distributed
+ return distributed(strategies, weights)

hypothesis-python/src/hypothesis/provisional.py

@@ -64,3 +64,40 @@ def ip6_addr_strings():
  """
  part = st.integers(0, 2 ** 16 - 1).map(u"{:04x}".format)
  return st.tuples(*[part] * 8).map(lambda a: u":".join(a).upper())
+
+
+def distributed(strategies, weights):
+ from hypothesis.internal.conjecture.utils import Sampler
+ from hypothesis.strategies import SearchStrategy
+ from hypothesis.searchstrategy.strategies import check_strategy
+ from hypothesis.internal.validation import check_type, InvalidArgument
+
+ class DistributedStrategy(SearchStrategy):
+ def __init__(self, strategies, weights):
+ SearchStrategy.__init__(self)
+ self.sampler = Sampler(weights)
+ self.strategies = strategies
+
+ def calc_has_reusable_values(self, recur):
+ return True
+
+ def do_draw(self, data):
+ strategy = self.strategies[self.sampler.sample(data)]
+ return strategy.do_draw(data)
+
+ assert strategies
+
+ for strategy in strategies:
+ check_strategy(strategy)
+
+ for weight in weights:
+ check_type((int, float), weight)
+ if weight < 0:
+ raise InvalidArgument("weight must be a positive number")
+
+ if len(strategies) != len(weights):
+ raise InvalidArgument(
+ "The number of weights must match the number of strategies"
+ )
+
+ return DistributedStrategy(strategies, weights)

hypothesis-python/src/hypothesis/strategies.py

@@ -32,6 +32,7 @@
  decimals,
  deferred,
  dictionaries,
+ distributed,
  emails,
  fixed_dictionaries,
  floats,
@@ -83,6 +84,7 @@
  "decimals",
  "deferred",
  "dictionaries",
+ "distributed",
  "emails",
  "fixed_dictionaries",
  "floats",