Szathmáry László honlapja @ DEIK

A sequence is a dynamic array. Same thing as a list in Python. Sequences are stored on the heap, thus they are garbage collected.

basic usage
def main(): li = [1, 8, 5] print(li) # [1, 8, 5] numbers = [] numbers.append(2) numbers.append(3) numbers.append(5) print(numbers) # [2, 3, 5] for n in numbers: print(n) print(len(numbers)) # 3	proc main() = var li = @[1, 8, 5] echo li # @[1, 8, 5] var numbers1: seq[int] var numbers2: seq[int] = @[] var numbers3 = newSeq[int]() echo numbers1 # @[] echo numbers2 # @[] echo numbers3 # @[] numbers1.add(2) numbers1.add(3) numbers1.add(5) echo numbers1 # @[2, 3, 5] for n in numbers1: echo(n) echo numbers1.len # 3

When you simply write [1, 2, 3], it's a static array. When you apply the '@' operator: @[1, 2, 3], it'll transform the static array to a dynamic array.

In the Nim code, numbers1, numbers2 and numbers3 are equivalent. They are all empty sequences.

var nums = @[] # ERROR: cannot infer the type

𝥶It doesn't work because the compiler cannot figure out the type of the sequence.

var nums = @[1, 2, 3] # OK

𝥶It's OK, nums will be a sequence of integers.

var numbers1: seq[int]

𝥶Here we declare a sequence of integers. Nim will initialize it, thus it becomes an empty sequence.

echo numbers1.len

𝥶This if UFCS. It's actually transformed to len(numbers1)