Collections¶

Lists¶

A list is an ordered, mutable sequence of values. Mixed types are allowed.

fruits = ["apple", "banana", "cherry"]
mixed  = [1, "two", 3.0, true, null]
empty  = []

Indexing¶

Zero-based. Reading out-of-range raises a RuntimeFault:

write(fruits[0])   # apple
write(fruits[2])   # cherry

Assignment by index¶

fruits[1] = "mango"
write(fruits)   # ["apple", "mango", "cherry"]

Iteration¶

for fruit in fruits {
    write(fruit)
}

List built-ins¶

Function	Description
`len(list)`	Number of elements
`append(list, value)`	Add element to the end (modifies in place)
`pop(list)`	Remove and return the last element
`pop(list, index)`	Remove and return the element at index

nums = [10, 20, 30]
append(nums, 40)
write(len(nums))     # 4
write(pop(nums))     # 40
write(pop(nums, 0))  # 10
write(nums)          # [20, 30]

Dictionaries¶

A dictionary maps keys to values. Keys must be strings or numbers.

person = {"name": "Alice", "age": 30}
empty  = {}

Accessing values¶

write(person["name"])   # Alice
write(person["age"])    # 30

Assigning values¶

person["age"] = 31
person["city"] = "Madrid"

Iteration¶

Iterating over a dictionary yields its keys:

for key in person {
    write($"{key}: {person[key]}")
}

Dictionary built-ins¶

Function	Description
`len(dict)`	Number of key-value pairs
`keys(dict)`	Returns a list of all keys
`values(dict)`	Returns a list of all values
`remove(dict, key)`	Remove key and return its value

write(keys(person))      # ["name", "age", "city"]
write(values(person))    # ["Alice", 31, "Madrid"]
write(remove(person, "city"))   # Madrid
write(len(person))       # 2