Lists

Lists are ordered, indexable collections of objects (similar to arrays in other languages). They can hold any type of object, including other lists.

Creating Lists

# Empty list
empty_list = []

# List with elements
numbers = [1, 2, 3, 4, 5]
mixed = [1, "hello", True, [2, 3]]

# List from a string (splits into characters)
chars = list("Neon")  # → ["N", "e", "o", "n"]

Accessing Elements

• Indexing starts at 0 (first element is at index 0).
• Use list[index] to get an element.

fruits = ["apple", "banana", "cherry"]
print(fruits[0])   # → "apple"
print(fruits[1])   # → "banana"

Modifying Lists

Operation	Example	Description
Append	append(fruits, "orange")	Adds "orange" to the end.
Insert	insert(fruits, 1, "mango")	Inserts "mango" at index 1.
Remove	remove(fruits, 0)	Removes element at index 0.
Length	len(fruits)	Returns the number of elements.
Reverse	reverse(fruits)	Reverses the list (returns a new list).
Sort	sortAsc(fruits)	Sorts in ascending order (modifies the list).
	sortDesc(fruits)	Sorts in descending order.
Index	index(fruits, "banana")	Returns the index of "banana" (or raises OutOfRange).
Count	count(fruits, "apple")	Counts occurrences of "apple".

List Operations

# Concatenation
list1 = [1, 2]
list2 = [3, 4]
combined = list1 + list2  # → [1, 2, 3, 4]

# Repetition
repeated = [1, 2] * 3  # → [1, 2, 1, 2, 1, 2]

# Membership check
"apple" in fruits  # → True
5 in numbers      # → False

List Comprehensions (Efficient List Building)

Neon provides listComp for efficient list construction.

Slow list construction:

squares = []
for (i, 0, 10) do
  if (i%2 == 0) then
    squares.append(i ** 2)
  end
end

Efficient version using listComp:

squares = listComp("i", 0, 10, 1, "i%2 == 0", "i ** 2")
# -> [0, 4, 16, 36, 64]

Deep Copying Lists

By default, copying a list shares references to its elements. Use copy() for a deep copy:

original = [[1, 2], [3, 4]]
shallow_copy = original  # Modifying shallow_copy affects original!
deep_copy = copy(original)  # Independent copy

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