roc/builtins/Int.roc
2020-01-21 10:09:54 -05:00

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interface Int
exposes [ Int ]
imports []
## Types
# Integer := Integer
## A 64-bit signed integer. All number literals without decimal points are #Int values.
##
## >>> 1
##
## >>> 0
##
## You can optionally put underscores in your #Int literals.
## They have no effect on the number's value, but can make large numbers easier to read.
##
## >>> 1_000_000
##
## See #Int.highest and #Int.lowest for the highest and
## lowest values that can be held in an #Int.
##
## If any operation would result in an #Int that is either too big
## or too small to fit in that range (e.g. running `Int.highest + 1`),
## then the operation will *overflow* or *underflow*, respectively.
## When this happens:
##
## * In a development build, you'll get an assertion failure.
## * In a release build, you'll get [wrapping overflow](https://en.wikipedia.org/wiki/Integer_overflow#Saturated_arithmetic), which is almost always a mathematically incorrect outcome for the requested operation.
##
## As such, it's very important to design your code not to exceed these bounds!
## If you need to do math outside these bounds, consider using
## a different representation other than #Int. The reason #Int has these
## bounds is for performance reasons.
#Int : Num Integer
## Arithmetic
## Divide two integers and discard any fractional part of the result.
##
## Division by zero is undefined in mathematics. As such, you should make
## sure never to pass zero as the denomaintor to this function!
##
## If zero does get passed as the denominator...
##
## * In a development build, you'll get an assertion failure.
## * In an optimized build, the function will return 0.
##
## `a // b` is shorthand for `Int.div a b`.
##
## >>> 5 // 7
##
## >>> Int.div 5 7
##
## >>> 8 // -3
##
## >>> Int.div 8 -3
##
## This is the same as the #// operator.
# div : Int, Int -> Int
## Perform flooring modulo on two integers.
##
## Modulo is the same as remainder when working with positive numbers,
## but if either number is negative, then modulo works differently.
##
## Additionally, flooring modulo uses #Float.floor on the result.
##
## (Use #Float.mod for non-flooring modulo.)
##
## Return `Err DivByZero` if the second integer is zero, because division by zero is undefined in mathematics.
##
## `a %% b` is shorthand for `Int.modFloor a b`.
##
## >>> 5 %% 7
##
## >>> Int.modFloor 5 7
##
## >>> -8 %% -3
##
## >>> Int.modFloor -8 -3
#modFloor : Int, Int -> Result DivByZero Int
## Bitwise
#bitwiseXor : Int -> Int -> Int
#bitwiseAnd : Int -> Int -> Int
#bitwiseNot : Int -> Int
## Limits
## The highest number that can be stored in an #Int without overflowing its
## available memory (64 bits total) and crashing.
##
## Note that this is smaller than the positive version of #Int.lowest,
## which means if you call #Num.abs on #Int.lowest, it will crash!
#highest : Int
highest = 0x7fff_ffff_ffff_ffff
## The lowest number that can be stored in an #Int without overflowing its
## available memory (64 bits total) and crashing.
##
## Note that the positive version of this number is this is larger than
## #Int.highest, which means if you call #Num.abs on #Int.lowest,
## it will crash!
#lowest : Int
lowest = -0x8000_0000_0000_0000