Merge "[docs] Docstrings for queries YAQL functions"
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@ -954,6 +954,30 @@ def zip_longest(*collections, **kwargs):
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@specs.parameter('predicate', yaqltypes.Lambda())
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@specs.parameter('selector', yaqltypes.Lambda())
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def join(engine, collection1, collection2, predicate, selector):
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""":yaql:join
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Returns list of selector applied to those combinations of collection1 and
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collection2 elements, for which predicate is true.
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:signature: collection1.join(collection2, predicate, selector)
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:receiverArg collection1: input collection
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:argType collection1: iterable
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:arg collection2: other input collection
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:argType collection2: iterable
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:arg predicate: function of two arguments to apply to every
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(collection1, collection2) pair, if returned value is true the pair is
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passed to selector
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:argType predicate: lambda
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:arg selector: function of two arguments to apply to every
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(collection1, collection2) pair, for which predicate returned true
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:argType selector: lambda
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:returnType: iterable
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.. code::
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yaql> [1,2,3,4].join([2,5,6], $1 > $2, [$1, $2])
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[[3, 2], [4, 2]]
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"""
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collection2 = utils.memorize(collection2, engine)
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for self_item in collection1:
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for other_item in collection2:
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@ -962,18 +986,51 @@ def join(engine, collection1, collection2, predicate, selector):
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@specs.method
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@specs.parameter('obj', nullable=True)
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@specs.parameter('value', nullable=True)
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@specs.parameter('times', int)
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def repeat(obj, times=-1):
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def repeat(value, times=-1):
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""":yaql:repeat
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Returns collection with value repeated.
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:signature: value.repeat(times => -1)
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:receiverArg value: value to be repeated
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:argType value: any
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:arg times: how many times repeat value. -1 by default, which means that
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returned value will be an iterator to the endless sequence of values
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:argType times: int
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:returnType: iterable
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.. code::
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yaql> 1.repeat(2)
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[1, 1]
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yaql> 1.repeat().take(3)
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[1, 1, 1]
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"""
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if times < 0:
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return itertools.repeat(obj)
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return itertools.repeat(value)
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else:
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return itertools.repeat(obj, times)
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return itertools.repeat(value, times)
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@specs.method
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@specs.parameter('collection', yaqltypes.Iterable())
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def cycle(collection):
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""":yaql:cycle
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Makes an iterator returning elements from the collection as if it cycled.
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:signature: collection.cycle()
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:receiverArg collection: value to be cycled
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:argType collection: iterable
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:returnType: iterator
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.. code::
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yaql> [1, 2].cycle().take(5)
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[1, 2, 1, 2, 1]
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"""
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return itertools.cycle(collection)
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@ -981,6 +1038,23 @@ def cycle(collection):
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@specs.parameter('collection', yaqltypes.Iterable())
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@specs.parameter('predicate', yaqltypes.Lambda())
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def take_while(collection, predicate):
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""":yaql:takeWhile
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Returns elements from the collection as long as the predicate is true.
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:signature: collection.takeWhile(predicate)
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:receiverArg collection: input collection
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:argType collection: iterable
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:arg predicate: function of one argument to apply to every
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collection value
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:argType predicate: lambda
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:returnType: iterable
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.. code::
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yaql> [1, 2, 3, 4, 5].takeWhile($ < 4)
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[1, 2, 3]
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"""
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return itertools.takewhile(predicate, collection)
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@ -988,12 +1062,48 @@ def take_while(collection, predicate):
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@specs.parameter('collection', yaqltypes.Iterable())
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@specs.parameter('predicate', yaqltypes.Lambda())
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def skip_while(collection, predicate):
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""":yaql:skipWhile
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Skips elements from the collection as long as the predicate is true.
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Then returns an iterator to collection of remaining elements
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:signature: collection.skipWhile(predicate)
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:receiverArg collection: input collection
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:argType collection: iterable
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:arg predicate: function of one argument to apply to every collection value
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:argType predicate: lambda
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:returnType: iterator
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.. code::
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yaql> [1, 2, 3, 4, 5].skipWhile($ < 3)
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[3, 4, 5]
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"""
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return itertools.dropwhile(predicate, collection)
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@specs.method
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@specs.parameter('collection', yaqltypes.Iterable())
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def index_of(collection, item):
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""":yaql:indexOf
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Returns the index in the collection of the first item which value is item.
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-1 is a return value if there is no such item
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:signature: collection.indexOf(item)
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:receiverArg collection: input collection
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:argType collection: iterable
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:arg item: value to find in collection
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:argType item: any
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:returnType: integer
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.. code::
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yaql> [1, 2, 3, 2].indexOf(2)
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1
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yaql> [1, 2, 3, 2].indexOf(102)
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-1
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"""
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for i, t in enumerate(collection):
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if t == item:
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return i
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@ -1003,6 +1113,23 @@ def index_of(collection, item):
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@specs.method
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@specs.parameter('collection', yaqltypes.Iterable())
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def last_index_of(collection, item):
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""":yaql:lastIndexOf
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Returns the index in the collection of the last item which value is item.
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-1 is a return value if there is no such item
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:signature: collection.lastIndexOf(item)
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:receiverArg collection: input collection
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:argType collection: iterable
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:arg item: value to find in collection
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:argType item: any
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:returnType: integer
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.. code::
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yaql> [1, 2, 3, 2].lastIndexOf(2)
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3
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"""
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index = -1
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for i, t in enumerate(collection):
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if t == item:
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@ -1014,6 +1141,25 @@ def last_index_of(collection, item):
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@specs.parameter('collection', yaqltypes.Iterable())
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@specs.parameter('predicate', yaqltypes.Lambda())
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def index_where(collection, predicate):
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""":yaql:indexWhere
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Returns the index in the collection of the first item which value
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satisfies the predicate. -1 is a return value if there is no such item
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:signature: collection.indexWhere(predicate)
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:receiverArg collection: input collection
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:argType collection: iterable
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:arg predicate: function of one argument to apply on every value
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:argType predicate: lambda
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:returnType: integer
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.. code::
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yaql> [1, 2, 3, 2].indexWhere($ > 2)
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2
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yaql> [1, 2, 3, 2].indexWhere($ > 3)
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-1
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"""
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for i, t in enumerate(collection):
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if predicate(t):
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return i
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@ -1024,6 +1170,23 @@ def index_where(collection, predicate):
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@specs.parameter('collection', yaqltypes.Iterable())
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@specs.parameter('predicate', yaqltypes.Lambda())
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def last_index_where(collection, predicate):
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""":yaql:lastIndexWhere
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Returns the index in the collection of the last item which value
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satisfies the predicate. -1 is a return value if there is no such item
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:signature: collection.lastIndexWhere(predicate)
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:receiverArg collection: input collection
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:argType collection: iterable
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:arg predicate: function of one argument to apply on every value
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:argType predicate: lambda
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:returnType: integer
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.. code::
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yaql> [1, 2, 3, 2].lastIndexWhere($ = 2)
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3
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"""
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index = -1
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for i, t in enumerate(collection):
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if predicate(t):
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@ -1036,6 +1199,23 @@ def last_index_where(collection, predicate):
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@specs.parameter('length', int)
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@specs.inject('to_list', yaqltypes.Delegate('to_list', method=True))
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def slice_(collection, length, to_list):
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""":yaql:slice
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Returns collection divided into list of collections with max size of
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new parts equal to length.
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:signature: collection.slice(length)
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:receiverArg collection: input collection
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:argType collection: iterable
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:arg length: max length of new collections
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:argType length: integer
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:returnType: list
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.. code::
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yaql> range(1,6).slice(2)
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[[1, 2], [3, 4], [5]]
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"""
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collection = iter(collection)
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while True:
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res = to_list(itertools.islice(collection, length))
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@ -1050,6 +1230,26 @@ def slice_(collection, length, to_list):
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@specs.parameter('predicate', yaqltypes.Lambda())
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@specs.inject('to_list', yaqltypes.Delegate('to_list', method=True))
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def split_where(collection, predicate, to_list):
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""":yaql:splitWhere
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Returns collection divided into list of collections where delimiters are
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values for which predicate returns true. Delimiters are deleted from
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result.
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:signature: collection.splitWhere(predicate)
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:receiverArg collection: input collection
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:argType collection: iterable
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:arg predicate: function of one argument to be applied on every
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element. Elements for which predicate returns true are delimiters for
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new list
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:argType predicate: lambda
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:returnType: list
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.. code::
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yaql> [1, 2, 3, 4, 5, 6, 7].splitWhere($ mod 3 = 0)
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[[1, 2], [4, 5], [7]]
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"""
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lst = to_list(collection)
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start = 0
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end = 0
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@ -1067,6 +1267,27 @@ def split_where(collection, predicate, to_list):
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@specs.parameter('predicate', yaqltypes.Lambda())
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@specs.inject('to_list', yaqltypes.Delegate('to_list', method=True))
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def slice_where(collection, predicate, to_list):
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""":yaql:sliceWhere
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Splits collection into lists. Within every list predicate evaluated
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on its items returns the same value while predicate evaluated on the
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items of the adjacent lists returns different values. Returns an iterator
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to lists.
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:signature: collection.sliceWhere(predicate)
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:receiverArg collection: input collection
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:argType collection: iterable
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:arg predicate: function of one argument to be applied on every
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element. Elements for which predicate returns true are delimiters for
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new list and are present in new collection as separate collections
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:argType predicate: lambda
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:returnType: iterator
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.. code::
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yaql> [1, 2, 3, 4, 5, 6, 7].sliceWhere($ mod 3 = 0)
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[[1, 2], [3], [4, 5], [6], [7]]
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"""
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lst = to_list(collection)
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start = 0
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end = 0
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@ -1087,6 +1308,24 @@ def slice_where(collection, predicate, to_list):
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@specs.parameter('index', int)
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@specs.inject('to_list', yaqltypes.Delegate('to_list', method=True))
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def split_at(collection, index, to_list):
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""":yaql:splitAt
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Splits collection into two lists by index.
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:signature: collection.splitAt(index)
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:receiverArg collection: input collection
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:argType collection: iterable
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:arg index: the index of collection to be delimiter for splitting
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:argType index: integer
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:returnType: list
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.. code::
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yaql> [1, 2, 3, 4].splitAt(1)
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[[1], [2, 3, 4]]
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yaql> [1, 2, 3, 4].splitAt(0)
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[[], [1, 2, 3, 4]]
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"""
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lst = to_list(collection)
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return [lst[:index], lst[index:]]
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@ -1095,6 +1334,31 @@ def split_at(collection, index, to_list):
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@specs.parameter('collection', yaqltypes.Iterable())
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@specs.parameter('selector', yaqltypes.Lambda())
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def aggregate(collection, selector, seed=utils.NO_VALUE):
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""":yaql:aggregate
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Applies selector of two arguments cumulatively: to the first two elements
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of collection, then to the result of the previous selector applying and
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to the third element, and so on. Returns the result of last selector
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applying.
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:signature: collection.aggregate(selector, seed => NoValue)
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:receiverArg collection: input collection
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:argType collection: iterable
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:arg selector: function of two arguments to be applied on every next
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pair of collection
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:argType selector: lambda
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:arg seed: if specified, it is used as start value for accumulating and
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becomes a default when the collection is empty. NoValue by default
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:argType seed: collection elements type
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:returnType: collection elements type
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.. code::
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yaql> [a,a,b,a,a].aggregate($1 + $2)
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"aabaa"
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yaql> [].aggregate($1 + $2, 1)
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1
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"""
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if seed is utils.NO_VALUE:
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return six.moves.reduce(selector, collection)
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else:
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@ -1105,6 +1369,20 @@ def aggregate(collection, selector, seed=utils.NO_VALUE):
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@specs.parameter('collection', yaqltypes.Iterable())
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@specs.inject('to_list', yaqltypes.Delegate('to_list', method=True))
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def reverse(collection, to_list):
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""":yaql:reverse
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Returns reversed collection, evaluated to list.
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:signature: collection.reverse()
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:receiverArg collection: input collection
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:argType collection: iterable
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:returnType: list
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.. code::
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yaql> [1, 2, 3, 4].reverse()
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[4, 3, 2, 1]
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"""
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return reversed(to_list(collection))
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@ -1146,6 +1424,45 @@ def _merge_dicts(dict1, dict2, list_merge_func, item_merger, max_levels=0):
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@specs.inject('to_list', yaqltypes.Delegate('to_list', method=True))
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def merge_with(engine, to_list, d, another, list_merger=None,
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item_merger=None, max_levels=0):
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""":yaql:mergeWith
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Performs a deep merge of two dictionaries.
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:signature: dict.mergeWith(another, listMerger => null,
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itemMerger => null, maxLevels => null)
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:receiverArg dict: input dictionary
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:argType dict: mapping
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:arg another: dictionary to merge with
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:argType another: mapping
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:arg listMerger: function to be applied while merging two lists. null is a
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default which means listMerger to be distinct(lst1 + lst2)
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:argType listMerger: lambda
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:arg itemMerger: function to be applied while merging two items. null is a
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default, which means itemMerger to be a second item for every pair.
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:argType itemMerger: lambda
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:arg maxLevels: number which describes how deeply merge dicts. 0 by
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default, which means going throughout them
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:argType maxLevels: int
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:returnType: mapping
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.. code::
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yaql> {'a'=> 1, 'b'=> 2, 'c'=> [1, 2]}.mergeWith({'d'=> 5, 'b'=> 3,
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'c'=> [2, 3]})
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{"a": 1, "c": [1, 2, 3], "b": 3, "d": 5}
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yaql> {'a'=> 1, 'b'=> 2, 'c'=> [1, 2]}.mergeWith({'d'=> 5, 'b'=> 3,
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'c'=> [2, 3]},
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$1+$2)
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{"a": 1, "c": [1, 2, 2, 3], "b": 3, "d": 5}
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yaql> {'a'=> 1, 'b'=> 2, 'c'=> [1, 2]}.mergeWith({'d'=> 5, 'b'=> 3,
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'c'=> [2, 3]},
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$1+$2, $1)
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{"a": 1, "c": [1, 2, 2, 3], "b": 2, "d": 5}
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yaql> {'a'=> 1, 'b'=> 2, 'c'=> [1, 2]}.mergeWith({'d'=> 5, 'b'=> 3,
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'c'=> [2, 3]},
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maxLevels => 1)
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{"a": 1, "c": [2, 3], "b": 3, "d": 5}
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"""
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if list_merger is None:
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list_merger = lambda lst1, lst2: to_list(
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distinct(engine, lst1 + lst2))
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@ -1155,6 +1472,26 @@ def merge_with(engine, to_list, d, another, list_merger=None,
|
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def is_iterable(value):
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""":yaql:isIterable
|
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Returns true if value is iterable, false otherwise.
|
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|
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:signature: isIterable(value)
|
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:arg value: value to be checked
|
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:argType value: any
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:returnType: boolean
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.. code::
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yaql> isIterable([])
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true
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yaql> isIterable(set(1,2))
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true
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yaql> isIterable("foo")
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false
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yaql> isIterable({"a" => 1})
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false
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"""
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return utils.is_iterable(value)
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@ -1162,6 +1499,31 @@ def is_iterable(value):
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@specs.parameter('collection', yaqltypes.Iterable())
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@specs.parameter('selector', yaqltypes.Lambda())
|
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def accumulate(collection, selector, seed=utils.NO_VALUE):
|
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""":yaql:accumulate
|
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|
||||
Applies selector of two arguments cumulatively to the items of collection
|
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from begin to end, so as to accumulate the collection to a list of
|
||||
intermediate values.
|
||||
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:signature: collection.accumulate(selector, seed => NoValue)
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:receiverArg collection: input collection
|
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:argType collection: iterable
|
||||
:arg selector: function of two arguments to be applied on every next
|
||||
pair of collection
|
||||
:argType selector: lambda
|
||||
:arg seed: value to use as the first for accumulating. noValue by default
|
||||
:argType seed: collection elements type
|
||||
:returnType: list
|
||||
|
||||
.. code::
|
||||
|
||||
yaql> [1, 2, 3].accumulate($1+$2)
|
||||
[1, 3, 6]
|
||||
yaql> [1, 2, 3].accumulate($1+$2, 100)
|
||||
[100, 101, 103, 106]
|
||||
yaql> [].accumulate($1+$2,1)
|
||||
[1]
|
||||
"""
|
||||
it = iter(collection)
|
||||
if seed is utils.NO_VALUE:
|
||||
try:
|
||||
@ -1182,6 +1544,37 @@ def accumulate(collection, selector, seed=utils.NO_VALUE):
|
||||
@specs.parameter('decycle', bool)
|
||||
def generate(engine, initial, predicate, producer, selector=None,
|
||||
decycle=False):
|
||||
""":yaql:generate
|
||||
|
||||
Returns iterator to values beginning from initial value with every next
|
||||
value produced with producer applied to every previous value, while
|
||||
predicate is true.
|
||||
Represents traversal over the list where each next element is obtained
|
||||
by the lambda result from the previous element.
|
||||
|
||||
:signature: generate(initial, predicate, producer, selector => null,
|
||||
decycle => false)
|
||||
:arg initial: value to start from
|
||||
:argType initial: any type
|
||||
:arg predicate: function of one argument to be applied on every new
|
||||
value. Stops generating if return value is false
|
||||
:argType predicate: lambda
|
||||
:arg producer: function of one argument to produce the next value
|
||||
:argType producer: lambda
|
||||
:arg selector: function of one argument to store every element in the
|
||||
resulted list. none by default which means to store producer result
|
||||
:argType selector: lambda
|
||||
:arg decycle: return only distinct values if true, false by default
|
||||
:argType decycle: boolean
|
||||
:returnType: list
|
||||
|
||||
.. code::
|
||||
|
||||
yaql> generate(0, $ < 10, $ + 2)
|
||||
[0, 2, 4, 6, 8]
|
||||
yaql> generate(1, $ < 10, $ + 2, $ * 1000)
|
||||
[1000, 3000, 5000, 7000, 9000]
|
||||
"""
|
||||
past_items = None if not decycle else set()
|
||||
while predicate(initial):
|
||||
if past_items is not None:
|
||||
@ -1202,6 +1595,36 @@ def generate(engine, initial, predicate, producer, selector=None,
|
||||
@specs.parameter('depth_first', bool)
|
||||
def generate_many(engine, initial, producer, selector=None, decycle=False,
|
||||
depth_first=False):
|
||||
""":yaql:generateMany
|
||||
|
||||
Returns iterator to values beginning from initial queue of values with
|
||||
every next value produced with producer applied to top of queue, while
|
||||
predicate is true.
|
||||
Represents tree traversal, where producer is used to get child nodes.
|
||||
|
||||
:signature: generateMany(initial, producer, selector => null,
|
||||
decycle => false, depthFirst => false)
|
||||
:arg initial: value to start from
|
||||
:argType initial: any type
|
||||
:arg producer: function to produce the next value for queue
|
||||
:argType producer: lambda
|
||||
:arg selector: function of one argument to store every element in the
|
||||
resulted list. none by default which means to store producer result
|
||||
:argType selector: lambda
|
||||
:arg decycle: return only distinct values if true, false by default
|
||||
:argType decycle: boolean
|
||||
:arg depthFirst: if true puts produced elements to the start of queue,
|
||||
false by default
|
||||
:argType depthFirst: boolean
|
||||
:returnType: list
|
||||
|
||||
.. code::
|
||||
|
||||
yaql> generateMany("1", {"1" => ["2", "3"],
|
||||
"2"=>["4"], "3"=>["5"]
|
||||
}.get($, []))
|
||||
["1", "2", "3", "4", "5"]
|
||||
"""
|
||||
past_items = None if not decycle else set()
|
||||
queue = utils.QueueType([initial])
|
||||
while queue:
|
||||
@ -1230,6 +1653,22 @@ def generate_many(engine, initial, producer, selector=None, decycle=False,
|
||||
@specs.parameter('collection', yaqltypes.Iterable())
|
||||
@specs.parameter('default', yaqltypes.Iterable())
|
||||
def default_if_empty(engine, collection, default):
|
||||
""":yaql:defaultIfEmpty
|
||||
|
||||
Returns default value if collection is empty.
|
||||
|
||||
:signature: collection.defaultIfEmpty(default)
|
||||
:receiverArg collection: input collection
|
||||
:argType collection: iterable
|
||||
:arg default: value to be returned if collection size is 0
|
||||
:argType default: iterable
|
||||
:returnType: iterable
|
||||
|
||||
.. code::
|
||||
|
||||
yaql> [].defaultIfEmpty([1, 2])
|
||||
[1, 2]
|
||||
"""
|
||||
if isinstance(collection, (utils.SequenceType, utils.SetType)):
|
||||
return default if len(collection) == 0 else collection
|
||||
collection = memorize(collection, engine)
|
||||
|
||||
Loading…
Reference in New Issue
Block a user