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float

float

§
:
numeric
 is
 
[Contains abstract features]

float -- floating point values


float is the abstract parent of concrete floating point features such as
f32 or f64.

Value Constructors

§
:
Any
 is
 
[Inherited from  numeric]
absolute value using `|a|` built from a `prefix |` and `postfix |` as an operator
alias of `a.abs`

Due to the low precedence of `|`, this works also on expressions like `|a-b|`, even
with spaces `| a-b |`, `|a - b|`, `| a-b|` or `|a-b |`.

Nesting, however, does not work, e.g, `| - |a| |`, this requires parentheses `|(- |a|)|`.

NYI: CLEANUP: Due to #3081, we need `postfix |` as the first operation, should be
`prefix |` first

Functions

§
:
Any
 => 
numeric.this 
[Inherited from  numeric]
absolute value
convert a float value to i32 dropping any fraction.
the value must be in the range of i32
§
:
Any
 => 
i64 
[Abstract feature]
convert a float value to i64 dropping any fraction.
the value must be in the range of i64
§
:
Any
 => 
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`
§
:
Any
 => 
u8 
[Inherited from  numeric]
 
[Abstract feature]
this numeric value as an u8
ceiling: the smallest integer greater or equal to this
§
:
Any
 => 
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.
§
:
Any
 => 
i32 
[Abstract feature]
the normalized exponent of this float
§
:
Any
 => 
i32 
[Abstract feature]
the biased exponent of this float
does this float value fit into an i64? This is redefined by children
of float that support `as_i64`.
§
:
Any
 => 
bool 
[Inherited from  numeric]
does this numeric value fit into an u8? This is redefined by children
of numeric that support `as_u8`.
floor: the greatest integer lower or equal to this
§
:
Any
 => 
float.this 
[Abstract feature]
§(other numeric.this)
:
Any
 => 
numeric.this 
[Inherited from  numeric]
 
[Abstract feature]
basic operations: 'infix %' (division remainder)
§(other numeric.this)
:
Any
 => 
bool 
[Inherited from  numeric]
§(other numeric.this)
:
Any
 => 
numeric.this 
[Inherited from  numeric]
 
[Abstract feature]
basic operations: 'infix *' (multiplication)
§(other numeric.this)
:
Any
 => 
bool 
[Inherited from  numeric]
§(other numeric.this)
:
Any
 => 
numeric.this 
[Inherited from  numeric]
 
[Abstract feature]
basic operations: 'infix **' (exponentiation)
§(other numeric.this)
:
Any
 => 
bool 
[Inherited from  numeric]
§(other numeric.this)
:
Any
 => 
num_option numeric.this 
[Inherited from  numeric]
 
[Abstract feature]
§(other numeric.this)
:
Any
 => 
numeric.this 
[Inherited from  numeric]
 
[Abstract feature]
§(other numeric.this)
:
Any
 => 
numeric.this 
[Inherited from  numeric]
§(other numeric.this)
:
Any
 => 
numeric.this 
[Inherited from  numeric]
 
[Abstract feature]
basic operations: 'infix +' (addition)
§(other numeric.this)
:
Any
 => 
bool 
[Inherited from  numeric]
§(other numeric.this)
:
Any
 => 
numeric.this 
[Inherited from  numeric]
§(other numeric.this)
:
Any
 => 
numeric.this 
[Inherited from  numeric]
 
[Abstract feature]
basic operations: 'infix -' (subtraction)
§(other numeric.this)
:
Any
 => 
bool 
[Inherited from  numeric]
§(other numeric.this)
:
Any
 => 
numeric.this 
[Inherited from  numeric]
§(other numeric.this)
:
Any
 => 
numeric.this 
[Inherited from  numeric]
 
[Abstract feature]
basic operations: 'infix /' (division)
§(other numeric.this)
:
Any
 => 
bool 
[Inherited from  numeric]
§(other float.this)
:
Any
 => 
bool 
[Abstract feature]
§(other float.this)
:
Any
 => 
bool 
[Abstract feature]
§(other float.this)
:
Any
 => 
bool 
[Abstract feature]
comparison

This provides comparison operators using IEEE semantics.

type.equality and type.lteq should be used for equivalence relations
and total ordering in the mathematical sense.
§(other float.this)
:
Any
 => 
bool 
[Abstract feature]
§(other float.this)
:
Any
 => 
bool 
[Abstract feature]
§
:
Any
 => 
bool 
[Inherited from  numeric]
§
:
Any
 => 
bool 
[Abstract feature]
is the bit denoting the sign of the number set?
this is different from smaller than zero since
there is +0, -0, NaN, etc. in floating point numbers.
§
:
Any
 => 
bool 
[Inherited from  numeric]
§
:
Any
 => 
u64 
[Abstract feature]
the normalized mantissa of this float
§
:
Any
 => 
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.
§
:
Any
 => 
numeric.this 
[Inherited from  numeric]
basic operations: 'prefix +' (identity)
§
:
Any
 => 
bool 
[Inherited from  numeric]
preconditions for basic operations: true if the operation's result is
representable and defined for the given values

default implementations all return `true` such that children have to
redefine these only for partial operations such as those resulting in
an overflow or that are undefined like a division by zero for most
types.
§
:
Any
 => 
numeric.this 
[Inherited from  numeric]
basic operations: 'prefix -' (negation)
§
:
Any
 => 
bool 
[Inherited from  numeric]
overflow checking operations
§
:
Any
 => 
numeric.this 
[Inherited from  numeric]
saturating operations
round floating point number
ties to away (0.5 => 1; -0.5 => -1; etc.)

NYI this could be made faster, see here:
https://cs.opensource.google/go/go/+/refs/tags/go1.18.1:src/math/floor.go;l=79
§
:
Any
 => 
i32 
[Inherited from  numeric]
sign function resulting in `-1`/`0`/`+1` depending on whether `numeric.this`
is less than, equal or larger than zero
§
:
Any
 => 
bool 
[Abstract feature]
true when the absolute value
is smaller than 0.001
or greater than 9_999_999

Value Types

§
:
Any
 is
 
[Inherited from  numeric]
absolute value using `|a|` built from a `prefix |` and `postfix |` as an operator
alias of `a.abs`

Due to the low precedence of `|`, this works also on expressions like `|a-b|`, even
with spaces `| a-b |`, `|a - b|`, `| a-b|` or `|a-b |`.

Nesting, however, does not work, e.g, `| - |a| |`, this requires parentheses `|(- |a|)|`.

NYI: CLEANUP: Due to #3081, we need `postfix |` as the first operation, should be
`prefix |` first

Type Features

§(val float.this.type)
:
Any
 is
 
[Abstract feature]
§(val float.this.type)
:
Any
 is
§
:
Any
 is
 
[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:

§(val float.this.type)
:
Any
 is
 
[Abstract feature]
§(val float.this.type)
:
Any
 is
§(val float.this.type)
:
Any
 is
 
[Abstract feature]
§(y float.this.type, x float.this.type)
:
Any
 is
 
[Abstract feature]
§(val float.this.type)
:
Any
 is
§
:
Any
 is
 
[Abstract feature]
number of bytes required to store this value
§(val float.this.type)
:
Any
 is
 
[Abstract feature]
§(val float.this.type)
:
Any
 is
 
[Abstract feature]
§
:
Any
 is
 
[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:

§
:
Any
 is
 
[Abstract feature]
§(a float.this.type, b float.this.type)
:
Any
 is
 
[Redefinition of numeric.type.equality]
equality

This provides an equivalence relation in the mathematical
sense and therefore breaks the IEEE semantics. infix = should
be used for IEEE semantics.

The equivalence relation is provided by the usual comparison
of floating-point numbers, with the definition of NaN = NaN.
§(val float.this.type)
:
Any
 is
 
[Abstract feature]
the `val`-th power of ℇ
i.e. ℇᵛᵃˡ
§
:
Any
 is
 
[Abstract feature]
number of bits used for exponent
§(val i64)
:
Any
 is
 
[Abstract feature]
convert an i64 value to a floating point value

if the value cannot be represented exactly, the result is either
the nearest higher or nearest lower value
§(v u32)
:
Any
 is
 
[Inherited from  numeric]
the value corresponding to v in whatever integer implementation we have,
maximum in case of overflow
§(a property.hashable.this.type)
:
Any
 is
 
[Inherited from  hashable]
 
[Abstract feature]
create hash code for this instance

This should satisfy the following condition:

(T.equality a b) : (T.hash_code a = T.hash_code b)
infinity
§(T 
type
)
:
Any
 is
 
[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.

is_of_integer_type(n T : numeric) => T : integer
say (is_of_integer_type 1234) # true
say (is_of_integer_type 3.14) # false

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

pair(a,b T) is

=>

or

val(n T) is

§(val float.this.type)
:
Any
 is
 
[Abstract feature]
is not a number?
§(val float.this.type)
:
Any
 is
 
[Abstract feature]
logarithm with base ℇ
§(base float.this.type, val float.this.type)
:
Any
 is
logarithm with base `base`
§(a float.this.type, b float.this.type)
:
Any
 is
 
[Redefinition of numeric.type.lteq]
total order

This provides a total order in the mathematical sense and
therefore breaks the IEEE semantics. infix <= should be
used for IEEE semantics.

The total order is provided by the usual comparison of
floating-point numbers, with the definition that NaN <= x,
for any x (including x = NaN).
the amount of bits that are used to encode the mantissa
§
:
Any
 is
 
[Abstract feature]
§
:
Any
 is
 
[Abstract feature]
§
:
Any
 is
 
[Abstract feature]
§
:
Any
 is
 
[Abstract feature]
§
:
Any
 is
 
[Inherited from  Type]
name of this type, including type parameters, e.g. 'option (list i32)'.
not a number
§
:
Any
 is
 
[Inherited from  numeric]
 
[Abstract feature]
identity element for 'infix *'
monoid of numeric with infix * operation. Will create product of all elements
it is applied to.
monoid of numeric with infix *^ operation. Will create product of all elements
it is applied to, stopping at max/min value in case of overflow.
non signaling not a number
§
:
Any
 is
 
[Abstract feature]
number of bits used for mantissa,
including leading '1' that is not actually stored
§(val float.this.type)
:
Any
 is
 
[Abstract feature]
§(val float.this.type)
:
Any
 is
 
[Abstract feature]
number of bits required to store this value
§(val float.this.type)
:
Any
 is
square root alias
§(val float.this.type)
:
Any
 is
 
[Abstract feature]
square root
monoid of numeric with infix + operation. Will create sum of all elements it
is applied to.
monoid of numeric with infix +^ operation. Will create sum of all elements it
is applied to, stopping at max/min value in case of overflow.
§(val float.this.type)
:
Any
 is
 
[Abstract feature]
§(val float.this.type)
:
Any
 is
 
[Abstract feature]
§
:
Any
 is
 
[Inherited from  numeric]
the constant '10' in whatever integer implementation we have, maximum in case of overflow
§
:
Any
 is
 
[Inherited from  numeric]
the constant '2' in whatever integer implementation we have, maximum in case of overflow
§
:
Any
 is
 
[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`.
§
:
Any
 is
 
[Inherited from  numeric]
 
[Abstract feature]
identity element for 'infix +'
§
:
Any
 is
 
[Abstract feature]
pi 3.14...
§
:
Any
 is
 
[Abstract feature]
eulers number 2.72..