# Subclasses often provide a more efficient implementation.
#
# Because of the `iterator` method, Collections instances can use
-# the `for` control structure:
+# the `for` control structure.
#
-# var x: Collection[U]
-# # ...
-# for u in x do
-# # u is a U
-# # ...
-# end
+# ~~~nitish
+# var x: Collection[U]
+# # ...
+# for u in x do
+# # u is a U
+# # ...
+# end
+# ~~~
#
-# that is equivalent with
+# that is equivalent with the following:
#
-# var x: Collection[U]
-# # ...
-# var i = x.iterator
-# while i.is_ok do
-# var u = i.item # u is a U
-# # ...
-# i.next
-# end
+# ~~~nitish
+# var x: Collection[U]
+# # ...
+# var i = x.iterator
+# while i.is_ok do
+# var u = i.item # u is a U
+# # ...
+# i.next
+# end
+# ~~~
interface Collection[E]
# Get a new iterator on the collection.
fun iterator: Iterator[E] is abstract
# How many occurrences of `item` are in the collection?
# Comparisons are done with ==
#
- # assert [10,20,10].count(10) == 2
+ # assert [10,20,10].count(10) == 2
fun count(item: E): Int
do
var nb = 0
# Return the first item of the collection
#
- # assert [1,2,3].first == 1
+ # assert [1,2,3].first == 1
fun first: E
do
assert length > 0
return iterator.item
end
- # Is the collection contains all the elements of `other`?
+ # Does the collection contain at least each element of `other`?
+ #
+ # assert [1,3,4,2].has_all([1..2]) == true
+ # assert [1,3,4,2].has_all([1..5]) == false
+ #
+ # Repeated elements in the collections are not considered.
#
- # assert [1,1,1].has_all([1]) == true
- # assert [1,1,1].has_all([1,2]) == false
- # assert [1,3,4,2].has_all([1..2]) == true
- # assert [1,3,4,2].has_all([1..5]) == false
+ # assert [1,1,1].has_all([1]) == true
+ # assert [1..5].has_all([1,1,1]) == true
+ #
+ # Note that the default implementation is general and correct for any lawful Collections.
+ # It is memory-efficient but relies on `has` so may be CPU-inefficient for some kind of collections.
fun has_all(other: Collection[E]): Bool
do
for x in other do if not has(x) then return false
return true
end
+
+ # Does the collection contain exactly all the elements of `other`?
+ #
+ # The same elements must be present in both `self` and `other`,
+ # but the order of the elements in the collections are not considered.
+ #
+ # assert [1..3].has_exactly([3,1,2]) == true # the same elements
+ # assert [1..3].has_exactly([3,1]) == false # 2 is not in the array
+ # assert [1..2].has_exactly([3,1,2]) == false # 3 is not in the range
+ #
+ # Repeated elements must be present in both collections in the same amount.
+ # So basically it is a multi-set comparison.
+ #
+ # assert [1,2,3,2].has_exactly([1,2,2,3]) == true # the same elements
+ # assert [1,2,3,2].has_exactly([1,2,3]) == false # more 2 in the first array
+ # assert [1,2,3].has_exactly([1,2,2,3]) == false # more 2 in the second array
+ #
+ # Note that the default implementation is general and correct for any lawful Collections.
+ # It is memory-efficient but relies on `count` so may be CPU-inefficient for some kind of collections.
+ fun has_exactly(other: Collection[E]): Bool
+ do
+ if length != other.length then return false
+ for e in self do if self.count(e) != other.count(e) then return false
+ return true
+ end
end
# Instances of the Iterator class generates a series of elements, one at a time.
# Is there a current item ?
fun is_ok: Bool is abstract
+
+ # Iterate over `self`
+ fun iterator: Iterator[E] do return self
+
+ # Post-iteration hook.
+ #
+ # Used to inform `self` that the iteration is over.
+ # Specific iterators can use this to free some resources.
+ #
+ # Is automatically invoked at the end of `for` structures.
+ #
+ # Do nothing by default.
+ fun finish do end
end
# A collection that contains only one item.
#
# Used to pass arguments by reference.
#
-# Also used when one want to give asingle element when a full
+# Also used when one want to give a single element when a full
# collection is expected
class Container[E]
super Collection[E]
- redef fun first do return _item
+ redef fun first do return item
redef fun is_empty do return false
redef fun length do return 1
- redef fun has(an_item) do return _item == an_item
+ redef fun has(an_item) do return item == an_item
- redef fun has_only(an_item) do return _item == an_item
+ redef fun has_only(an_item) do return item == an_item
redef fun count(an_item)
do
- if _item == an_item then
+ if item == an_item then
return 1
else
return 0
redef fun iterator do return new ContainerIterator[E](self)
- # Create a new instance with a given initial value.
- init(e: E) do _item = e
-
# The stored item
- readable writable var _item: E
+ var item: E is writable
end
# This iterator is quite stupid since it is used for only one item.
-class ContainerIterator[E]
+private class ContainerIterator[E]
super Iterator[E]
redef fun item do return _container.item
- redef fun next do _is_ok = false
-
- init(c: Container[E]) do _container = c
+ redef fun next do is_ok = false
- redef readable var _is_ok: Bool = true
+ redef var is_ok: Bool = true
- var _container: Container[E]
+ var container: Container[E]
end
# Items can be removed from this collection
# Add each item of `coll`.
# var a = [1,2]
- # a.add_all [3..5]
+ # a.add_all([3..5])
# assert a.has(4) == true
# assert a.has(10) == false
fun add_all(coll: Collection[E]) do for i in coll do add(i)
# # ...
# s.add(a)
# assert s.has(b) == true
-interface Set[E: Object]
+interface Set[E]
super SimpleCollection[E]
redef fun has_only(item)
# Because of the law between `==` and `hash`, `hash` is redefined to be the sum of the hash of the elements
redef fun hash
do
- var res = 0
- for e in self do res += res.hash
+ # 23 is a magic number empirically determined to be not so bad.
+ var res = 23 + length
+ # Note: the order of the elements must not change the hash value.
+ # So, unlike usual hash functions, the accumulator is not combined with itself.
+ for e in self do res += e.hash
return res
end
+
+ # Returns the union of this set with the `other` set
+ fun union(other: Set[E]): Set[E]
+ do
+ var nhs = new_set
+ nhs.add_all self
+ nhs.add_all other
+ return nhs
+ end
+
+ # Returns the intersection of this set with the `other` set
+ fun intersection(other: Set[E]): Set[E]
+ do
+ var nhs = new_set
+ for v in self do if other.has(v) then nhs.add(v)
+ return nhs
+ end
+
+ # Returns a new instance of `Set`.
+ #
+ # Depends on the subclass, mainly used for copy services
+ # like `union` or `intersection`.
+ protected fun new_set: Set[E] is abstract
end
# MapRead are abstract associative collections: `key` -> `item`.
-interface MapRead[K: Object, E]
+interface MapRead[K, V]
# Get the item at `key`
#
# var x = new HashMap[String, Int]
#
# If the key is not in the map, `provide_default_value` is called (that aborts by default)
# See `get_or_null` and `get_or_default` for safe variations.
- fun [](key: K): E is abstract
+ fun [](key: K): V is abstract
# Get the item at `key` or null if `key` is not in the map.
#
# assert x.get_or_null("four") == 4
# assert x.get_or_null("five") == null
#
- # Note: use `has_key` and `[]` if you need the distinction bewteen a key associated with null, and no key.
- fun get_or_null(key: K): nullable E
+ # Note: use `has_key` and `[]` if you need the distinction between a key associated with null, and no key.
+ fun get_or_null(key: K): nullable V
do
if has_key(key) then return self[key]
return null
# assert x.get_or_default("four", 40) == 4
# assert x.get_or_default("five", 50) == 50
#
- fun get_or_default(key: K, default: E): E
+ fun get_or_default(key: K, default: V): V
do
if has_key(key) then return self[key]
return default
end
- # Depreciated alias for `keys.has`
+ # Is there an item associated with `key`?
+ #
+ # var x = new HashMap[String, Int]
+ # x["four"] = 4
+ # assert x.has_key("four") == true
+ # assert x.has_key("five") == false
+ #
+ # By default it is a synonymous to `keys.has` but could be redefined with a direct implementation.
fun has_key(key: K): Bool do return self.keys.has(key)
# Get a new iterator on the map.
- fun iterator: MapIterator[K, E] is abstract
+ fun iterator: MapIterator[K, V] is abstract
# Return the point of view of self on the values only.
# Note that `self` and `values` are views on the same data;
# x["four"] = 4
# assert x.values.has(4) == true
# assert x.values.has(5) == false
- fun values: Collection[E] is abstract
+ fun values: Collection[V] is abstract
# Return the point of view of self on the keys only.
# Note that `self` and `keys` are views on the same data;
#
# Note: the value is returned *as is*, implementations may want to store the value in the map before returning it
# @toimplement
- protected fun provide_default_value(key: K): E do abort
+ protected fun provide_default_value(key: K): V do abort
+
+ # Does `self` and `other` have the same keys associated with the same values?
+ #
+ # ~~~
+ # var a = new HashMap[String, Int]
+ # var b = new ArrayMap[Object, Numeric]
+ # assert a == b
+ # a["one"] = 1
+ # assert a != b
+ # b["one"] = 1
+ # assert a == b
+ # b["one"] = 2
+ # assert a != b
+ # ~~~
+ redef fun ==(other)
+ do
+ if not other isa MapRead[nullable Object, nullable Object] then return false
+ if other.length != self.length then return false
+ for k, v in self do
+ if not other.has_key(k) then return false
+ if other[k] != v then return false
+ end
+ return true
+ end
end
# Maps are associative collections: `key` -> `item`.
# assert map.values.has(1) == true
# assert map.values.has(3) == false
#
-interface Map[K: Object, E]
- super MapRead[K, E]
+interface Map[K, V]
+ super MapRead[K, V]
# Set the `value` at `key`.
#
# x["four"] = 4
# assert x["four"] == 4
#
- # If the key was associated with a value, this old value is discarted
+ # If the key was associated with a value, this old value is discarded
# and replaced with the new one.
#
# x["four"] = 40
# assert x["four"] == 40
# assert x.values.has(4) == false
#
- fun []=(key: K, value: E) is abstract
+ fun []=(key: K, value: V) is abstract
# Add each (key,value) of `map` into `self`.
# If a same key exists in `map` and `self`, then the value in self is discarded.
# assert x["four"] == 40
# assert x["five"] == 5
# assert x["nine"] == 90
- fun recover_with(map: Map[K, E])
+ fun recover_with(map: MapRead[K, V])
do
var i = map.iterator
while i.is_ok do
# var x = new HashMap[String, Int]
# x["four"] = 4
# x.clear
- # x.keys.has("four") == false
+ # assert x.keys.has("four") == false
#
# ENSURE `is_empty`
fun clear is abstract
- redef fun values: RemovableCollection[E] is abstract
+ redef fun values: RemovableCollection[V] is abstract
redef fun keys: RemovableCollection[K] is abstract
end
# Iterators for Map.
-interface MapIterator[K: Object, E]
+interface MapIterator[K, V]
# The current item.
# Require `is_ok`.
- fun item: E is abstract
+ fun item: V is abstract
# The key of the current item.
# Require `is_ok`.
# Set a new `item` at `key`.
#fun item=(item: E) is abstract
+
+ # Post-iteration hook.
+ #
+ # Used to inform `self` that the iteration is over.
+ # Specific iterators can use this to free some resources.
+ #
+ # Is automatically invoked at the end of `for` structures.
+ #
+ # Do nothing by default.
+ fun finish do end
end
# Iterator on a 'keys' point of view of a map
-class MapKeysIterator[K: Object, V]
+class MapKeysIterator[K, V]
super Iterator[K]
# The original iterator
- var iterator: MapIterator[K, V]
+ var original_iterator: MapIterator[K, V]
- redef fun is_ok do return self.iterator.is_ok
- redef fun next do self.iterator.next
- redef fun item do return self.iterator.key
+ redef fun is_ok do return self.original_iterator.is_ok
+ redef fun next do self.original_iterator.next
+ redef fun item do return self.original_iterator.key
end
# Iterator on a 'values' point of view of a map
-class MapValuesIterator[K: Object, V]
+class MapValuesIterator[K, V]
super Iterator[V]
# The original iterator
- var iterator: MapIterator[K, V]
+ var original_iterator: MapIterator[K, V]
- redef fun is_ok do return self.iterator.is_ok
- redef fun next do self.iterator.next
- redef fun item do return self.iterator.item
+ redef fun is_ok do return self.original_iterator.is_ok
+ redef fun next do self.original_iterator.next
+ redef fun item do return self.original_iterator.item
end
# Sequences are indexed collections.
var p = 0
var i = iterator
while i.is_ok do
- if p>pos and i.item == item then return i.index
+ if p>=pos and i.item == item then return i.index
i.next
p += 1
end
return res
end
- redef fun iterator: IndexedIterator[E] is abstract
-
# Two sequences are equals if they have the same items in the same order.
#
# var a = new List[Int]
# Because of the law between `==` and `hash`, `hash` is redefined to be the sum of the hash of the elements
redef fun hash
do
- var res = 0
- for e in self do res += res.hash
+ # The 17 and 2/3 magic numbers were determined empirically.
+ # Note: the standard hash functions djb2, sbdm and fnv1 were also
+ # tested but were comparable (or worse).
+ var res = 17 + length
+ for e in self do
+ res = res * 3 / 2
+ if e != null then res += e.hash
+ end
+ return res
+ end
+
+ redef fun iterator: IndexedIterator[E] is abstract
+
+ # Gets a new Iterator starting at position `pos`
+ #
+ # var iter = [10,20,30,40,50].iterator_from(2)
+ # assert iter.to_a == [30, 40, 50]
+ fun iterator_from(pos: Int): IndexedIterator[E]
+ do
+ var res = iterator
+ while pos > 0 and res.is_ok do
+ res.next
+ pos -= 1
+ end
+ return res
+ end
+
+ # Gets an iterator starting at the end and going backwards
+ #
+ # var reviter = [1,2,3].reverse_iterator
+ # assert reviter.to_a == [3,2,1]
+ fun reverse_iterator: IndexedIterator[E] is abstract
+
+ # Gets an iterator on the chars of self starting from `pos`
+ #
+ # var reviter = [10,20,30,40,50].reverse_iterator_from(2)
+ # assert reviter.to_a == [30,20,10]
+ fun reverse_iterator_from(pos: Int): IndexedIterator[E]
+ do
+ var res = reverse_iterator
+ while pos > 0 and res.is_ok do
+ res.next
+ pos -= 1
+ end
return res
end
end
# var a = [1,2,3]
# a.append([7..9])
# assert a == [1,2,3,7,8,9]
- fun append(coll: Collection[E]) do for i in coll do push(i)
+ #
+ # Alias of `add_all`
+ fun append(coll: Collection[E]) do add_all(coll)
# Remove the last item.
#
# assert a == [20,10,1,2,3]
fun unshift(e: E) is abstract
+ # Add all items of `coll` before the first one.
+ #
+ # var a = [1,2,3]
+ # a.prepend([7..9])
+ # assert a == [7,8,9,1,2,3]
+ #
+ # Alias of `insert_at(coll, 0)`
+ fun prepend(coll: Collection[E]) do insert_all(coll, 0)
+
# Remove the first item.
# The second item thus become the first.
#
# a.insert(100, 2)
# assert a == [10, 20, 100, 30, 40]
#
- # REQUIRE `index >= 0 and index < length`
+ # REQUIRE `index >= 0 and index <= length`
# ENSURE `self[index] == item`
fun insert(item: E, index: Int) is abstract
+ # Insert all elements at a given position, following elements are shifted.
+ #
+ # var a = [10, 20, 30, 40]
+ # a.insert_all([100..102], 2)
+ # assert a == [10, 20, 100, 101, 102, 30, 40]
+ #
+ # REQUIRE `index >= 0 and index <= length`
+ # ENSURE `self[index] == coll.first`
+ fun insert_all(coll: Collection[E], index: Int)
+ do
+ assert index >= 0 and index < length
+ if index == length then
+ add_all(coll)
+ end
+ for c in coll do
+ insert(c, index)
+ index += 1
+ end
+ end
+
# Remove the item at `index` and shift all following elements
#
# var a = [10,20,30]
end
# Associative arrays that internally uses couples to represent each (key, value) pairs.
-interface CoupleMap[K: Object, E]
- super Map[K, E]
+# This is an helper class that some specific implementation of Map may implements.
+interface CoupleMap[K, V]
+ super Map[K, V]
+
# Return the couple of the corresponding key
# Return null if the key is no associated element
- protected fun couple_at(key: K): nullable Couple[K, E] is abstract
+ protected fun couple_at(key: K): nullable Couple[K, V] is abstract
+
+ # Return a new iteralot on all couples
+ # Used to provide `iterator` and others
+ protected fun couple_iterator: Iterator[Couple[K,V]] is abstract
+
+ redef fun iterator do return new CoupleMapIterator[K,V](couple_iterator)
redef fun [](key)
do
return c.second
end
end
+
+ redef fun has_key(key) do return couple_at(key) != null
end
# Iterator on CoupleMap
#
-# Actually is is a wrapper around an iterator of the internal array of the map.
-class CoupleMapIterator[K: Object, E]
- super MapIterator[K, E]
+# Actually it is a wrapper around an iterator of the internal array of the map.
+private class CoupleMapIterator[K, V]
+ super MapIterator[K, V]
redef fun item do return _iter.item.second
#redef fun item=(e) do _iter.item.second = e
_iter.next
end
- var _iter: Iterator[Couple[K,E]]
-
- init(i: Iterator[Couple[K,E]]) do _iter = i
+ var iter: Iterator[Couple[K,V]]
end
# Some tools ###################################################################
class Couple[F, S]
# The first element of the couple.
- readable writable var _first: F
+ var first: F is writable
# The second element of the couple.
- readable writable var _second: S
-
- # Create a new instance with a first and a second object.
- init(f: F, s: S)
- do
- _first = f
- _second = s
- end
+ var second: S is writable
end
nitlanguage / nit.git / blobdiff