core/Int8
Utility functions on 8-bit signed integers.
Note that most operations are available as built-in operators (e.g. 1 + 1
).
Import from the core library to use this module.
import Int8 "mo:core/Int8";
Type Int8
type Int8 = Prim.Types.Int8
8-bit signed integers.
Value minValue
let minValue : Int8
Minimum 8-bit integer value, -2 ** 7
.
Example:
assert Int8.minValue == -128;
Value maxValue
let maxValue : Int8
Maximum 8-bit integer value, +2 ** 7 - 1
.
Example:
assert Int8.maxValue == +127;
Function toInt
func toInt(_ : Int8) : Int
Converts an 8-bit signed integer to a signed integer with infinite precision.
Example:
assert Int8.toInt(123) == (123 : Int);
Function fromInt
func fromInt(_ : Int) : Int8
Converts a signed integer with infinite precision to an 8-bit signed integer.
Traps on overflow/underflow.
Example:
assert Int8.fromInt(123) == (+123 : Int8);
Function fromIntWrap
func fromIntWrap(_ : Int) : Int8
Converts a signed integer with infinite precision to an 8-bit signed integer.
Wraps on overflow/underflow.
Example:
assert Int8.fromIntWrap(-123) == (-123 : Int8);
Function fromInt16
func fromInt16(_ : Int16) : Int8
Converts a 16-bit signed integer to an 8-bit signed integer.
Traps on overflow/underflow.
Example:
assert Int8.fromInt16(123) == (+123 : Int8);
Function toInt16
func toInt16(_ : Int8) : Int16
Converts an 8-bit signed integer to a 16-bit signed integer.
Example:
assert Int8.toInt16(123) == (+123 : Int16);
Function fromNat8
func fromNat8(_ : Nat8) : Int8
Converts an unsigned 8-bit integer to a signed 8-bit integer.
Wraps on overflow/underflow.
Example:
assert Int8.fromNat8(123) == (+123 : Int8);
Function toNat8
func toNat8(_ : Int8) : Nat8
Converts a signed 8-bit integer to an unsigned 8-bit integer.
Wraps on overflow/underflow.
Example:
assert Int8.toNat8(-1) == (255 : Nat8); // underflow
Function toText
func toText(x : Int8) : Text
Converts an integer number to its textual representation.
Example:
assert Int8.toText(-123) == "-123";
Function abs
func abs(x : Int8) : Int8
Returns the absolute value of x
.
Traps when x == -2 ** 7
(the minimum Int8
value).
Example:
assert Int8.abs(-123) == +123;
Function min
func min(x : Int8, y : Int8) : Int8
Returns the minimum of x
and y
.
Example:
assert Int8.min(+2, -3) == -3;
Function max
func max(x : Int8, y : Int8) : Int8
Returns the maximum of x
and y
.
Example:
assert Int8.max(+2, -3) == +2;
Function equal
func equal(x : Int8, y : Int8) : Bool
Equality function for Int8 types.
This is equivalent to x == y
.
Example:
assert Int8.equal(-1, -1);
Note: The reason why this function is defined in this library (in addition
to the existing ==
operator) is so that you can use it as a function
value to pass to a higher order function. It is not possible to use ==
as a function value at the moment.
Example:
let a : Int8 = -123;
let b : Int8 = 123;
assert not Int8.equal(a, b);
Function notEqual
func notEqual(x : Int8, y : Int8) : Bool
Inequality function for Int8 types.
This is equivalent to x != y
.
Example:
assert Int8.notEqual(-1, -2);
Note: The reason why this function is defined in this library (in addition
to the existing !=
operator) is so that you can use it as a function
value to pass to a higher order function. It is not possible to use !=
as a function value at the moment.
Function less
func less(x : Int8, y : Int8) : Bool
"Less than" function for Int8 types.
This is equivalent to x < y
.
Example:
assert Int8.less(-2, 1);
Note: The reason why this function is defined in this library (in addition
to the existing <
operator) is so that you can use it as a function
value to pass to a higher order function. It is not possible to use <
as a function value at the moment.
Function lessOrEqual
func lessOrEqual(x : Int8, y : Int8) : Bool
"Less than or equal" function for Int8 types.
This is equivalent to x <= y
.
Example:
assert Int8.lessOrEqual(-2, -2);
Note: The reason why this function is defined in this library (in addition
to the existing <=
operator) is so that you can use it as a function
value to pass to a higher order function. It is not possible to use <=
as a function value at the moment.
Function greater
func greater(x : Int8, y : Int8) : Bool
"Greater than" function for Int8 types.
This is equivalent to x > y
.
Example:
assert Int8.greater(-2, -3);
Note: The reason why this function is defined in this library (in addition
to the existing >
operator) is so that you can use it as a function
value to pass to a higher order function. It is not possible to use >
as a function value at the moment.
Function greaterOrEqual
func greaterOrEqual(x : Int8, y : Int8) : Bool
"Greater than or equal" function for Int8 types.
This is equivalent to x >= y
.
Example:
assert Int8.greaterOrEqual(-2, -2);
Note: The reason why this function is defined in this library (in addition
to the existing >=
operator) is so that you can use it as a function
value to pass to a higher order function. It is not possible to use >=
as a function value at the moment.
Function compare
func compare(x : Int8, y : Int8) : Order.Order
General-purpose comparison function for Int8
. Returns the Order
(
either #less
, #equal
, or #greater
) of comparing x
with y
.
Example:
assert Int8.compare(-3, 2) == #less;
This function can be used as value for a high order function, such as a sort function.
Example:
import Array "mo:core/Array";
assert Array.sort([1, -2, -3] : [Int8], Int8.compare) == [-3, -2, 1];
Function neg
func neg(x : Int8) : Int8
Returns the negation of x
, -x
.
Traps on overflow, i.e. for neg(-2 ** 7)
.
Example:
assert Int8.neg(123) == -123;
Note: The reason why this function is defined in this library (in addition
to the existing -
operator) is so that you can use it as a function
value to pass to a higher order function. It is not possible to use -
as a function value at the moment.
Function add
func add(x : Int8, y : Int8) : Int8
Returns the sum of x
and y
, x + y
.
Traps on overflow/underflow.
Example:
assert Int8.add(100, 23) == +123;
Note: The reason why this function is defined in this library (in addition
to the existing +
operator) is so that you can use it as a function
value to pass to a higher order function. It is not possible to use +
as a function value at the moment.
Example:
import Array "mo:core/Array";
assert Array.foldLeft<Int8, Int8>([1, -2, -3], 0, Int8.add) == -4;
Function sub
func sub(x : Int8, y : Int8) : Int8
Returns the difference of x
and y
, x - y
.
Traps on overflow/underflow.
Example:
assert Int8.sub(123, 23) == +100;
Note: The reason why this function is defined in this library (in addition
to the existing -
operator) is so that you can use it as a function
value to pass to a higher order function. It is not possible to use -
as a function value at the moment.
Example:
import Array "mo:core/Array";
assert Array.foldLeft<Int8, Int8>([1, -2, -3], 0, Int8.sub) == 4;
Function mul
func mul(x : Int8, y : Int8) : Int8
Returns the product of x
and y
, x * y
.
Traps on overflow/underflow.
Example:
assert Int8.mul(12, 10) == +120;
Note: The reason why this function is defined in this library (in addition
to the existing *
operator) is so that you can use it as a function
value to pass to a higher order function. It is not possible to use *
as a function value at the moment.
Example:
import Array "mo:core/Array";
assert Array.foldLeft<Int8, Int8>([1, -2, -3], 1, Int8.mul) == 6;
Function div
func div(x : Int8, y : Int8) : Int8
Returns the signed integer division of x
by y
, x / y
.
Rounds the quotient towards zero, which is the same as truncating the decimal places of the quotient.
Traps when y
is zero.
Example:
assert Int8.div(123, 10) == +12;
Note: The reason why this function is defined in this library (in addition
to the existing /
operator) is so that you can use it as a function
value to pass to a higher order function. It is not possible to use /
as a function value at the moment.
Function rem
func rem(x : Int8, y : Int8) : Int8
Returns the remainder of the signed integer division of x
by y
, x % y
,
which is defined as x - x / y * y
.
Traps when y
is zero.
Example:
assert Int8.rem(123, 10) == +3;
Note: The reason why this function is defined in this library (in addition
to the existing %
operator) is so that you can use it as a function
value to pass to a higher order function. It is not possible to use %
as a function value at the moment.
Function pow
func pow(x : Int8, y : Int8) : Int8
Returns x
to the power of y
, x ** y
.
Traps on overflow/underflow and when y < 0 or y >= 8
.
Example:
assert Int8.pow(2, 6) == +64;
Note: The reason why this function is defined in this library (in addition
to the existing **
operator) is so that you can use it as a function
value to pass to a higher order function. It is not possible to use **
as a function value at the moment.
Function bitnot
func bitnot(x : Int8) : Int8
Returns the bitwise negation of x
, ^x
.
Example:
assert Int8.bitnot(-16 /* 0xf0 */) == +15 // 0x0f;
Note: The reason why this function is defined in this library (in addition
to the existing ^
operator) is so that you can use it as a function
value to pass to a higher order function. It is not possible to use ^
as a function value at the moment.
Function bitand
func bitand(x : Int8, y : Int8) : Int8
Returns the bitwise "and" of x
and y
, x & y
.
Example:
assert Int8.bitand(0x1f, 0x70) == +16 // 0x10;
Note: The reason why this function is defined in this library (in addition
to the existing &
operator) is so that you can use it as a function
value to pass to a higher order function. It is not possible to use &
as a function value at the moment.
Function bitor
func bitor(x : Int8, y : Int8) : Int8
Returns the bitwise "or" of x
and y
, x | y
.
Example:
assert Int8.bitor(0x0f, 0x70) == +127 // 0x7f;
Note: The reason why this function is defined in this library (in addition
to the existing |
operator) is so that you can use it as a function
value to pass to a higher order function. It is not possible to use |
as a function value at the moment.
Function bitxor
func bitxor(x : Int8, y : Int8) : Int8
Returns the bitwise "exclusive or" of x
and y
, x ^ y
.
Example:
assert Int8.bitxor(0x70, 0x7f) == +15 // 0x0f;
Note: The reason why this function is defined in this library (in addition
to the existing ^
operator) is so that you can use it as a function
value to pass to a higher order function. It is not possible to use ^
as a function value at the moment.
Function bitshiftLeft
func bitshiftLeft(x : Int8, y : Int8) : Int8
Returns the bitwise left shift of x
by y
, x << y
.
The right bits of the shift filled with zeros.
Left-overflowing bits, including the sign bit, are discarded.
For y >= 8
, the semantics is the same as for bitshiftLeft(x, y % 8)
.
For y < 0
, the semantics is the same as for bitshiftLeft(x, y + y % 8)
.
Example:
assert Int8.bitshiftLeft(1, 4) == +16 // 0x10 equivalent to `2 ** 4`.;
Note: The reason why this function is defined in this library (in addition
to the existing <<
operator) is so that you can use it as a function
value to pass to a higher order function. It is not possible to use <<
as a function value at the moment.
Function bitshiftRight
func bitshiftRight(x : Int8, y : Int8) : Int8
Returns the signed bitwise right shift of x
by y
, x >> y
.
The sign bit is retained and the left side is filled with the sign bit.
Right-underflowing bits are discarded, i.e. not rotated to the left side.
For y >= 8
, the semantics is the same as for bitshiftRight(x, y % 8)
.
For y < 0
, the semantics is the same as for bitshiftRight (x, y + y % 8)
.
Example:
assert Int8.bitshiftRight(64, 4) == +4 // equivalent to `64 / (2 ** 4)`;
Note: The reason why this function is defined in this library (in addition
to the existing >>
operator) is so that you can use it as a function
value to pass to a higher order function. It is not possible to use >>
as a function value at the moment.
Function bitrotLeft
func bitrotLeft(x : Int8, y : Int8) : Int8
Returns the bitwise left rotatation of x
by y
, x <<> y
.
Each left-overflowing bit is inserted again on the right side.
The sign bit is rotated like other bits, i.e. the rotation interprets the number as unsigned.
Changes the direction of rotation for negative y
.
For y >= 8
, the semantics is the same as for bitrotLeft(x, y % 8)
.
Example:
assert Int8.bitrotLeft(0x11 /* 0b0001_0001 */, 2) == +68 // 0b0100_0100 == 0x44.;
Note: The reason why this function is defined in this library (in addition
to the existing <<>
operator) is so that you can use it as a function
value to pass to a higher order function. It is not possible to use <<>
as a function value at the moment.
Function bitrotRight
func bitrotRight(x : Int8, y : Int8) : Int8
Returns the bitwise right rotation of x
by y
, x <>> y
.
Each right-underflowing bit is inserted again on the right side.
The sign bit is rotated like other bits, i.e. the rotation interprets the number as unsigned.
Changes the direction of rotation for negative y
.
For y >= 8
, the semantics is the same as for bitrotRight(x, y % 8)
.
Example:
assert Int8.bitrotRight(0x11 /* 0b0001_0001 */, 1) == -120 // 0b1000_1000 == 0x88.;
Note: The reason why this function is defined in this library (in addition
to the existing <>>
operator) is so that you can use it as a function
value to pass to a higher order function. It is not possible to use <>>
as a function value at the moment.
Function bittest
func bittest(x : Int8, p : Nat) : Bool
Returns the value of bit p
in x
, x & 2**p == 2**p
.
If p >= 8
, the semantics is the same as for bittest(x, p % 8)
.
This is equivalent to checking if the p
-th bit is set in x
, using 0 indexing.
Example:
assert Int8.bittest(64, 6);
Function bitset
func bitset(x : Int8, p : Nat) : Int8
Returns the value of setting bit p
in x
to 1
.
If p >= 8
, the semantics is the same as for bitset(x, p % 8)
.
Example:
assert Int8.bitset(0, 6) == +64;
Function bitclear
func bitclear(x : Int8, p : Nat) : Int8
Returns the value of clearing bit p
in x
to 0
.
If p >= 8
, the semantics is the same as for bitclear(x, p % 8)
.
Example:
assert Int8.bitclear(-1, 6) == -65;
Function bitflip
func bitflip(x : Int8, p : Nat) : Int8
Returns the value of flipping bit p
in x
.
If p >= 8
, the semantics is the same as for bitclear(x, p % 8)
.
Example:
assert Int8.bitflip(127, 6) == +63;
Function bitcountNonZero
func bitcountNonZero(x : Int8) : Int8
Returns the count of non-zero bits in x
.
Example:
assert Int8.bitcountNonZero(0x0f) == +4;
Function bitcountLeadingZero
func bitcountLeadingZero(x : Int8) : Int8
Returns the count of leading zero bits in x
.
Example:
assert Int8.bitcountLeadingZero(0x08) == +4;
Function bitcountTrailingZero
func bitcountTrailingZero(x : Int8) : Int8
Returns the count of trailing zero bits in x
.
Example:
assert Int8.bitcountTrailingZero(0x10) == +4;
Function addWrap
func addWrap(x : Int8, y : Int8) : Int8
Returns the sum of x
and y
, x +% y
.
Wraps on overflow/underflow.
Example:
assert Int8.addWrap(2 ** 6, 2 ** 6) == -128; // overflow
Note: The reason why this function is defined in this library (in addition
to the existing +%
operator) is so that you can use it as a function
value to pass to a higher order function. It is not possible to use +%
as a function value at the moment.
Function subWrap
func subWrap(x : Int8, y : Int8) : Int8
Returns the difference of x
and y
, x -% y
.
Wraps on overflow/underflow.
Example:
assert Int8.subWrap(-2 ** 7, 1) == +127; // underflow
Note: The reason why this function is defined in this library (in addition
to the existing -%
operator) is so that you can use it as a function
value to pass to a higher order function. It is not possible to use -%
as a function value at the moment.
Function mulWrap
func mulWrap(x : Int8, y : Int8) : Int8
Returns the product of x
and y
, x *% y
. Wraps on overflow.
Wraps on overflow/underflow.
Example:
assert Int8.mulWrap(2 ** 4, 2 ** 4) == 0; // overflow
Note: The reason why this function is defined in this library (in addition
to the existing *%
operator) is so that you can use it as a function
value to pass to a higher order function. It is not possible to use *%
as a function value at the moment.
Function powWrap
func powWrap(x : Int8, y : Int8) : Int8
Returns x
to the power of y
, x **% y
.
Wraps on overflow/underflow.
Traps if y < 0 or y >= 8
.
Example:
assert Int8.powWrap(2, 7) == -128; // overflow
Note: The reason why this function is defined in this library (in addition
to the existing **%
operator) is so that you can use it as a function
value to pass to a higher order function. It is not possible to use **%
as a function value at the moment.
Function range
func range(fromInclusive : Int8, toExclusive : Int8) : Iter.Iter<Int8>
Returns an iterator over Int8
values from the first to second argument with an exclusive upper bound.
import Iter "mo:core/Iter";
let iter = Int8.range(1, 4);
assert iter.next() == ?1;
assert iter.next() == ?2;
assert iter.next() == ?3;
assert iter.next() == null;
If the first argument is greater than the second argument, the function returns an empty iterator.
import Iter "mo:core/Iter";
let iter = Int8.range(4, 1);
assert iter.next() == null; // empty iterator
Function rangeInclusive
func rangeInclusive(from : Int8, to : Int8) : Iter.Iter<Int8>
Returns an iterator over Int8
values from the first to second argument, inclusive.
import Iter "mo:core/Iter";
let iter = Int8.rangeInclusive(1, 3);
assert iter.next() == ?1;
assert iter.next() == ?2;
assert iter.next() == ?3;
assert iter.next() == null;
If the first argument is greater than the second argument, the function returns an empty iterator.
import Iter "mo:core/Iter";
let iter = Int8.rangeInclusive(4, 1);
assert iter.next() == null; // empty iterator
Function allValues
func allValues() : Iter.Iter<Int8>
Returns an iterator over all Int8 values, from minValue to maxValue.
import Iter "mo:core/Iter";
let iter = Int8.allValues();
assert iter.next() == ?-128;
assert iter.next() == ?-127;
assert iter.next() == ?-126;
// ...