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Ring_Buffer

container.Ring_Buffer

(T 
type
, M 
type
:
mutate, size i64)
 ref
:
Any
 is
Ring_Buffer -- A simple fixed-size ring buffer

A feature defining a ring buffer of a fixed number of elements of a given
type `T`. The ring buffer can be used locally or for communication between
threads.

Type Parameters

the type of elements stored in this buffer
effect used to modify this buffer

If this ring buffer is to be used to communicate between threads,
this mutate effect must be a multi-thread implementation of mutate like
`concur.blocking_mutate`. An instance of this mustate effect must be
instated by when this Ring_Buffer is constructed and when it is accessed.

Fields

the maximum number of elements that can be stored in
this buffer

Functions

(v T)
 => 
bool
add an element to this ring buffer

Result is true iff ring buffer had space for one more element and `v` was
added to it, false iff the ring buffer is full and was not changed.
 => 
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`
the number of values currently stored in the ring buffer
(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.
is this buffer empty?
is this buffer full?
peek return the oldest element from this ring buffer without changing the buffer

Result is an option containing the oldest element iff the ring buffer was
not empty. Otherwise, result is nil.
poll remove the oldest element from this ring buffer

Result is an option containing the removed element iff the ring buffer was
not empty. Otherwise, result is nil.
 => 
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.
(v T)
 => 
unit
put is a blocking version of add: add an element to this ring buffer,
wait in case the buffer is full
take is a blocking version of poll: remove the oldest element from this ring buffer

Result is the removed element. If none is available, this will block until one is
available.

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:

 => 
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:

(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

 => 
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