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Binary_Heap_Queue

container.Binary_Heap_Queue

(LM 
type
:
mutate, T 
type
)
 ref
:
Mutable_Priority_Queue T
 is
[Private constructor]
A mutable priority queue implemented using a binary heap

Time complexity of internal operations is amortized, due to expanding/shrinking
of internal array, this can be avoided by setting a minimum size and
staying within that limit

Merging queues is not supported as it would be linear with a binary heap,
enqueue_all can be used, but if merging is frequently required
a different implementation would be better suited

Type Parameters

the mutate effect
type of the elements in the queue

Functions

 => 
String
[Inherited from  Any]
create a String from this instance. Unless redefined, `a.as_string` will
create `"instance[T]"` where `T` is the dynamic type of `a`
create a multiline string representation of the binary heap
using a centered, pretty-printed tree layout (balanced/symmetric)

Note: this will likely fail on very large queues (~2000)
as the whole string is constructed recursively at once
But in these cases the horizontal representation is likely not suitable

e.g.

create a multiline string representation of the binary heap
using an indented, top-down tree layout (filesystem-style)

This is more efficient than as_string_tree_pretty,
and works on larger trees

e.g.

all elements in this queue as an unordered Sequence
does this queue contain elem?

Time complexity: O(n)
number of elements in this queue
get and remove the element with highest priority

this is the element with either minimum or maximum value
depending on the chosen queue/comparator

Time complexity: amortized O(log n) or O(log n) when staying within min_size
(R 
type
, F 
type
: Typed_Function R, f F)
 => 
R
[Inherited from  Any]
dynamic_apply -- apply `f.call` to `Any.this`'s dynamic type and value

This can be used to perform operation on values depending on their dynamic
type.

Here is an example that takes a `Sequence Any` that may contain boxed values
of types `i32` and `f64`. We can now write a feature `get_f64` that extracts
these values converted to `f64` and build a function `sum` that sums them up
as follows:


 => 
Type
[Inherited from  Any]
Get the dynamic type of this instance. For value instances `x`, this is
equal to `type_of x`, but for `x` with a `ref` type `x.dynamic_type` gives
the actual runtime type, while `type_of x` results in the static
compile-time type.

There is no dynamic type of a type instance since this would result in an
endless hierarchy of types. So for Type values, dynamic_type is redefined
to just return Type.type.
add an element to the queue

Time complexity: amortized O(log n) or O(log n) when staying within min_size
(elements Sequence T)
 => 
unit
[Inherited from  Mutable_Priority_Queue]
iteratively add all elements to the queue

Note: Depending on the implementation, creating a new queue this way may be
less efficient than using one of the ..._from functions to construct
it from an unordered sequence of elements.
enqueue elem and then dequeue (return and remove) the highest priority element

this is more efficient (factor 2) than an enqueue followed by a dequeue

Time complexity: amortized O(log n) or O(log n) when staying within min_size
is this queue empty?
get the first element without removing it from the queue
nil iff queue is empty

Time complexity: O(1)
 => 
String
[Inherited from  Any]
convenience prefix operator to create a string from a value.

This permits usage of `$` as a prefix operator in a similar way both
inside and outside of constant strings: $x and "$x" will produce the
same string.

Type Functions

 => 
String
[Inherited from  Type]
string representation of this type to be used for debugging.

result has the form "Type of '<name>'", but this might change in the future

redefines:

Create a priority queue from the given elements that returns the elements
in the order defined by the the supplied comparator `less_than_or_equal`

Note: In the worst case this is more efficient than iterative `enqueue` or
`enqueue_all`, running in O(n) time rather than O(n log n).
But the actual runtime depends on the order of the elements,
for (almost) ordered elements iterative inserts will be faster.
 => 
Type
[Inherited from  Type]
There is no dynamic type of a type instance since this would result in an
endless hierarchy of types, so dynamic_type is redefined to just return
Type.type here.

redefines:

Create a new priority queue that returns the elements in the
order defined by the the supplied comparator `less_than_or_equal`
Create a new priority queue that returns the elements in the
order defined by the the supplied comparator `less_than_or_equal`
Create a new priority queue that returns the largest element first
using natural ordering of the elements
Create a new priority queue that returns the largest element first
using natural ordering of the elements
Create a new priority queue that returns the smallest element first
using natural ordering of the elements
Create a new priority queue that returns the smallest element first
using natural ordering of the elements
(T 
type
)
 => 
bool
[Inherited from  Type]
Is this type assignable to a type parameter with constraint `T`?

The result of this is a compile-time constant that can be used to specialize
code for a particular type.


it is most useful in conjunction with preconditions or `if` statements as in


or

Create a priority queue from the given elements
which returns largest element first using natural ordering of the elements

Note: In the worst case this is more efficient than iterative `enqueue` or
`enqueue_all`, running in O(n) time rather than O(n log n).
But the actual runtime depends on the order of the elements,
for (almost) ordered elements iterative inserts will be faster.
Create a priority queue from the given elements
which returns smallest element first using natural ordering of the elements

Note: In the worst case this is more efficient than iterative `enqueue` or
`enqueue_all`, running in O(n) time rather than O(n log n).
But the actual runtime depends on the order of the elements,
for (almost) ordered elements iterative inserts will be faster.
 => 
String
[Inherited from  Type]
name of this type, including type parameters, e.g. 'option (list i32)'.
 => 
String
[Inherited from  Type]
convenience prefix operator to create a string from a value.

This permits usage of `$` as a prefix operator in a similar way both
inside and outside of constant strings: $x and "$x" will produce the
same string.

NYI: Redefinition allows the type feature to be distinguished from its normal counterpart, see #3913

redefines:

 => 
Type
[Inherited from  Any]
Get a type as a value.

This is a feature with the effect equivalent to Fuzion's `expr.type` call tail.
It is recommended to use `expr.type` and not `expr.type_value`.

`type_value` is here to show how this can be implemented and to illustrate the
difference to `dynamic_type`.
0.095dev (GIT hash fe578dbae82d257bfb6d755e3b05abbf37247dbe)
last changed: 2026-05-12