Vectors

The vec module defines the vector type and all the vector manipulation related functions.

A vector is a sequence container that can store heterogeneous types.

All the given examples assume the following imports:

let vec = import('std/vec');
let io = import('std/io');

`vector` Member Functions

len
empty
front
back
push
pop
insert
erase
lastidx
set
at
operator []
slice
each
next

new

vec.new(elems...) -> vector

Creates a new vector using the given elements

Example:

let v = vec.new(12, 'Hello', 3.14);
io.println(v);

Gives the output:

[12, Hello, 3.14000000000000012434]

empty

vector.empty() -> bool

Checks whether the vector is empty

Example:

io.println(vec.new(0, 1, 2).empty());
io.println(vec.new().empty());

Gives the output:

false
true

front

vector.front() -> value

Returns the first element of the vector, or nil if the vector is empty

Example:

io.println(vec.new(0, 1, 2).front());
io.println(vec.new().front());

Gives the output:

0
(nil)

back

vector.back() -> value

Returns the last element of the vector, or nil if the vector is empty

Example:

io.println(vec.new(0, 1, 2).back());
io.println(vec.new().back());

Gives the output:

2
(nil)

push

vector.push(elem) -> vector

Appends elem to the vector and returns the modified vector

Example:

let v = vec.new(0);
v.push(1);
io.println(v.push(2));

Gives the output:

[0, 1, 2]

pop

vector.pop() -> vector

Removes the last element and returns the modified vector

Example:

let v = vec.new(0, 1, 2);
v.pop();
io.println(v.pop());

Gives the output:

[0]

insert

vector.insert(idx: int, elem) -> vector

Inserts the elem element at index idx and returns the modified vector

Example:

let v = vec.new(0, 2);
v.insert(2, 3);
io.println(v.insert(1, 1));

Gives the output:

[0, 1, 2, 3]

erase

vector.erase(idx: int) -> vector

Removes one element at index idx and returns the modified vector

Example:

let v = vec.new(0, 1, 9, 12, 2);
v.erase(3);
io.println(v.erase(2));

Gives the output:

[0, 1, 2]

set

vector.set(idx: int, elem) -> vector

Replaces the element at index idx with elem and returns the modified vector

Example:

let v = vec.new(0, 0, 0);
v.set(0, 2);
io.println(v.set(1, 1));

Gives the output:

[2, 1, 0]

at

vector.at(idx: int) -> value

Returns the element at index idx, or nil if out of range

Example:

let v = vec.new(0, 1, 2);
io.println(v.at(2));
io.println(v.at(3));

Gives the output:

2
(nil)

operator []

vector[idx: int] -> value

Returns the element at index idx, or nil if out of range

Example:

let v = vec.new(0, 1, 2);
io.println(v[2]);
io.println(v[3]);

Gives the output:

2
(nil)

slice

vector.slice(start: int, end: int = -1) -> vector

Extracts the elements from start to end - 1 and returns them in a new vector. If end == -1 then the slice ends at the end of the vector. Any modification in the elements of a slice will affect its original vector as well

Example:

let v = vec.new(0, 1, 2, 3);
io.println(v.slice(1));
io.println(v.slice(1, 3));

Gives the output:

[1, 2, 3]
[1, 2]

each

vector.each() -> iterator

Returns an iterator pointing to the first element, allowing easy vector iteration

Example:

let v = vec.new(0, 1, 2);
for elem in v.each() {
    io.println(elem);
}

Gives the output:

0
1
2

iterator.next() -> value

Returns the value pointed by the iterator, or nil if out of range, and then advances the iterator to the next element

Example:

let v = vec.new(0, 1, 2, 3);
let iter = v.each();
for i in range(v.len() + 1) {
    io.println(iter.next());
}

Gives the output:

0
1
2
3
(nil)

Feral Lang