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u8

u8

u8 -- 8-bit unsigned integer values

Fields

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

§
 => 
numeric.this  
[Inherited from  numeric]
absolute value
§
 => 
array u8  
[Inherited from  wrap_around]
this integer as an array of bytes (little endian)
§
 => 
String  
[Inherited from  integer]
convert this to a decimal number in a string. If negative, add "-" as
the first character.

redefines:

§
(base u32)
 => 
String  
[Inherited from  integer]
convert this to a number using the given base. If negative, add "-" as
the first character.
§
(len i32, base u32)
 => 
String  
[Inherited from  integer]
convert this to a number using the given base. If negative, add "-" as
the first character. Extend with leading "0" until the length is at
least len
§
 => 
u8  
[Redefinition of  numeric.as_u8]
as_i128 => as_i32.as_i128

redefines:

§
 => 
String  
[Inherited from  integer]
create binary representation
§
(len i32)
 => 
String  
[Inherited from  integer]
create binary representation with given number of digits.
§
 => 
String  
[Inherited from  integer]
create decimal representation
§
(len i32)
 => 
String  
[Inherited from  integer]
create decimal representation with given number of digits.
§
 => 
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.
§
 => 
bool  
[Redefinition of  numeric.fits_in_u8]
does this u8 fit into an u8?

redefines:

§
(b integer.this)
 => 
integer.this  
[Inherited from  integer]
greatest common divisor of this and b

note that this assumes zero to be divisible by any positive integer.
§
 => 
String  
[Inherited from  integer]
create hexadecimal representation
§
(len i32)
 => 
String  
[Inherited from  integer]
create hexadecimal representation with given number of digits.
find the highest 1 bit in this integer and return integer with
this single bit set or 0 if this is 0.
§
(other u8)
 => 
u8  
[Redefinition of  numeric.infix %]

redefines:

§
(other integer.this)
 => 
bool  
[Inherited from  integer]

redefines:

§
(other integer.this)
 => 
bool  
[Inherited from  integer]
test divisibility by other
§
(other u8)
 => 
u8  
[Redefinition of  integer.infix &]
bitwise and, or and xor operations

redefines:

multiplication, with check for overflow

redefines:

§
(other num.this.wrap_around.this)
 => 
bool  
[Inherited from  wrap_around]

redefines:

exponentiation for positive exponent

'zero ** zero' is permitted and results in 'one'.

redefines:

§
(other num.this.wrap_around.this)
 => 
bool  
[Inherited from  wrap_around]

redefines:

exponentiation with overflow checking semantics

'zero **? zero' is permitted and results in 'one'.

redefines:

exponentiation with saturating semantics

'zero **^ zero' is permitted and results in 'one'.

redefines:

exponentiation with wrap-around semantics

'zero **° zero' is permitted and results in 'one'.

redefines:


redefines:

§
(other u8)
 => 
u8  
[Redefinition of  num.wrap_around.infix *°]
addition, with check for overflow

redefines:

§
(other num.this.wrap_around.this)
 => 
bool  
[Inherited from  wrap_around]

redefines:


redefines:


redefines:

§
(other u8)
 => 
u8  
[Redefinition of  num.wrap_around.infix +°]
subtraction, with check for overflow

redefines:

§
(other num.this.wrap_around.this)
 => 
bool  
[Inherited from  wrap_around]

redefines:


redefines:


redefines:

§
(other u8)
 => 
u8  
[Redefinition of  num.wrap_around.infix -°]
defining an integer interval from this to other, both inclusive

special cases of interval a..b:

a < b: the interval from a to b, both inclusive
a == b: the interval containing only one element, a
a > b: an empty interval
§
(other u8)
 => 
u8  
[Redefinition of  numeric.infix /]
division and remainder with check for div-by-zero

redefines:

§
(other integer.this)
 => 
bool  
[Inherited from  integer]
preconditions used in 'numeric' for basic operations: true if the
operation is permitted for the given values

redefines:

create a fraction
§
(other u8)
 => 
u8  
[Redefinition of  integer.infix <<]

redefines:

§
(other u8)
 => 
u8  
[Redefinition of  integer.infix >>]
shift operations (unsigned)

redefines:

§
(other u8)
 => 
u8  
[Redefinition of  integer.infix ^]

redefines:

§
(other u8)
 => 
u8  
[Redefinition of  integer.infix |]

redefines:

create a fraction via unicode fraction slash \u2044 '⁄ '
is this u8 an ASCII white-space character?
§
 => 
bool  
[Inherited from  wrap_around]
check if this type of wrap_around is bounded

wrap_arounds are assumed to be a bound set by default, so
this returns true unless redefined by an implementation

redefines:

§
 => 
bool  
[Inherited from  wrap_around]
§
 => 
bool  
[Inherited from  wrap_around]
§
 => 
bool  
[Inherited from  numeric]
§
 => 
bool  
[Inherited from  numeric]
§
 => 
u8  
[Redefinition of  integer.low8bits]
the least significant byte of this integer

redefines:

§
 => 
String  
[Inherited from  integer]
create octal representation
§
(len i32)
 => 
String  
[Inherited from  integer]
create octal representation with given number of digits.
count the number of 1 bits in the binary representation of this
integer.
would addition + other cause an overflow or underflow?
would exponentiation 'this ** other' cause an overflow?
would multiplication * other cause an overflow or underflow?
would subtraction - other cause an overflow or underflow?
an infinite integer Sequence starting from this up to the maximum value
has_interval.this.max
an infinite integer Sequence starting from this up to the maximum value
has_interval.this.max

NYI: CLEANUP: Eventually remove `postfix ..` or `postfix ..∞` in favor of the
other one, for now this is here to show that `∞` is a legal symbol in an operator.
§
 => 
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.
§
 => 
numeric.this  
[Inherited from  numeric]
basic operations: 'prefix +' (identity)
§
 => 
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.
negation, with check for overflow

redefines:

§
 => 
bool  
[Inherited from  wrap_around]
preconditions used in 'numeric' for basic operations: true if the
operation is permitted for the given values

redefines:

overflow checking operations

redefines:

saturating operations

redefines:

neg, add, sub, mul with wrap-around semantics
bitwise NOT

redefines:

§
 => 
integer.this  
[Inherited from  integer]
bitwise NOT (Unicode alias)
§
 => 
i32  
[Inherited from  numeric]
sign function resulting in `-1`/`0`/`+1` depending on whether `numeric.this`
is less than, equal or larger than zero
count the number of trailing zeros in this integer.
would negation cause an overflow?

Type Functions

returns the number in whose bit representation all bits are ones
§
 => 
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:

§
 => 
i32  
[Inherited from  wrap_around]
how many bytes does this integer use?
§
 => 
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:

§
(a u8, b u8)
 => 
bool  
[Redefinition of  numeric.type.equality]
equality
§
(v u32)
 => 
numeric.this.type  
[Inherited from  numeric]
the value corresponding to v in whatever integer implementation we have,
maximum in case of overflow
§
(a u8.this.type)
 => 
u64  
create hash code from this number
§
(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.

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

§
 => 
bool  
[Inherited from  equatable]
additional restrictions on when equality is permitted,
e.g., `option T` might require `T : property.equatable`.
to implement `equality`
§
(a u8, b u8)
 => 
bool  
[Redefinition of  numeric.type.lteq]
total order
§
 => 
u8  
[Redefinition of  num.wrap_around.type.max]
maximum
§
 => 
u8  
[Redefinition of  num.wrap_around.type.min]
minimum
§
 => 
String  
[Inherited from  Type]
name of this type, including type parameters, e.g. 'option (list i32)'.
§
 => 
u8  
[Redefinition of  numeric.type.one]
identity element for 'infix *'

redefines:

§
 => 
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:

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.
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.
§
 => 
numeric.this.type  
[Inherited from  numeric]
the constant '10' in whatever integer implementation we have, maximum in case of overflow
§
 => 
numeric.this.type  
[Inherited from  numeric]
the constant '2' in whatever integer implementation we have, maximum in case of overflow
§
 => 
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`.
§
 => 
u8  
[Redefinition of  numeric.type.zero]
identity element for 'infix +'

redefines: