accessors.md

Data Access

at(a, i)

at allows to acces a single item from a collection.

at(3:5, 2)                          =>  4
at("abc",3)                         =>  'c'
at([1 2; 3 4],1)                    =>  [1 3]'
at(ones(2,3,4),3)                   =>  ones(2,3)

setat!(a, i, value)

setat! allows to modify items in a collection. It returns the collection.

a = [1 2 3; 4 5 6]
setat!(a, 2, [0, 1])                => [1 0 3; 4 1 6]
a = ["a", 0, "c"]
setat!(a, 2, "b")                   => ["a","b","c"]

fst(a), snd(a), third(a), last(a)

fst(a)                              =>  at(a,1)
snd(a)                              =>  at(a,2)
third(a)                            =>  at(a,3)
last(a)                             =>  at(a,len(a))

part(a, ind)

part(1:10, 3:5)                     =>  3:5
part("abc", 2:3)                    =>  "bc"
part(1:10, [3,5,8])                 =>  [3,5,8]
part("abc", [3,1,2,2])              =>  "cabb"
a = [1 2 3; 4 5 6]
part(a, 2:3)                        =>  [2 3; 5 6]

trimmedpart(a, ind)

Like part, but ignores indices which would access elements which do not exist.

trimmedpart("abc", 2:10)    => "bc"

take(a, n)

Take up to n items from the beginning.

take([1 2 3 4 5], 3)        =>  [1 2 3]
take(1:3, 100)              =>  1:3

takelast(a, n)

Take up to n items from the end.

takelast(1:10, 2)           =>  9:10
takelast(1:3, 100)          =>  1:3

drop

droplast

tail

partition

partsoflen

extract