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bool

bool

bool -- Standard Fuzion type 'bool'

We need to apologize to George Boole for crippling his name a bit,
just to safe us from typing one more letter. But at least we stop
here and do not use boo, bo or similar.

bool is a choice type that can either be true_ of false_.

Note that 'true_' and 'false_' themselves are not of type 'bool'.
Routines 'true' and 'false' are the preferred way to get a constant
value of type 'bool'.

Functions

create an option from a lazily evaluated value depending on this bool
 => 
String
[Redefinition of  Any.as_string]
as human readable string

redefines:

(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.
and with eager evaluation
and with lazy evaluation
implies
xor, either or

true if exatly one of the two
bools is true
or with eager evaluation
or with lazy evaluation
not
 => 
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.
(T 
type
, a Lazy T, b Lazy T)
 => 
T
ternary ? : -- NYI: This will be replaced by a more powerful match syntax

Type Functions

monoid of bool with infix & operation. Will be true iff all elements are
true.
(B 
type
..., values B...)
 => 
bool
takes an arbitrary amount of bool arguments and returns true if and only if
all of them are true
monoid of bool with infix | operation. Will be false iff all elements are
false.
(B 
type
..., values B...)
 => 
bool
takes an arbitrary amount of bool arguments and returns true if and only if
any of them is true
 => 
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:

equality check implementation for inherited property.equatable
create hash code for this instance

This should satisfy the following condition:

(T.equality a b) : (T.hash_code a = T.hash_code b)
(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)'.
monoid of bool with infix ^ operation. Will be true iff an odd number of
elements is true. This gives the even parity.
 => 
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 b85caf7d9723bbbca0d1dcdfa7ea0cb016405931)
last changed: 2026-04-16