Take and Drop Items¶

take¶

    @take(3:i32, (1,2,3,4,5,6):i32)
(1,2,3):i32
    @take(-3:i32, (1,2,3,4,5,6):i32)
(4,5,6):i32

Function take returns the leading n items (when n is positive) or the tailing n times (when n is negative) from a value v. If n is greater than the length of v, the extra slots are filled with the default values depending on their current types.

Type Rules¶

Int, Any -> determined by the 2nd argument
_  , _   -> domain error

Shape Rules¶

shape left value

drop¶

    @drop(3:i32, (1,2,3,4,5,6):i32)
(4,5,6):i32
    @drop(-3:i32, (1,2,3,4,5,6):i32)
(1,2,3):i32

Function drop drops the leading n (when n is positive) or the tailing n (when n is negative) from a value v and returns the remaining values. If n is greater or equal to the length of v, an empty value is returned.

Type Rules¶

Int, Any -> determined by the 2nd argument
_  , _   -> domain error

Shape Rules¶

Shape Left Value

Discussion¶

Function take and drop are interchangable in some cases
- take(3,x) is the same as drop(len(x)-3,x) if len(x)>=3