Title here
Summary here
Range Over Iterators in R Programming Language
Our first program demonstrates how to iterate over a custom list and generate Fibonacci sequences using iterators. Here’s the full source code translated to Python:
class Element:
def __init__(self, val=None, next=None):
self.val = val
self.next = next
class List:
def __init__(self):
self.head = None
self.tail = None
def push(self, v):
new_element = Element(val=v)
if self.tail is None:
self.head = new_element
self.tail = self.head
else:
self.tail.next = new_element
self.tail = self.tail.next
def all(self):
current = self.head
def iterator():
nonlocal current
while current is not None:
yield current.val
current = current.next
return iterator()
def gen_fib():
a, b = 1, 1
def iterator():
nonlocal a, b
while True:
yield a
a, b = b, a + b
return iterator()
def main():
lst = List()
lst.push(10)
lst.push(13)
lst.push(23)
# Iterating over the list elements using the custom iterator
for e in lst.all():
print(e)
# Collecting all elements into a list
all_elements = list(lst.all())
print("all:", all_elements)
# Generating Fibonacci numbers and iterating over them
fib_iterator = gen_fib()
for n in fib_iterator:
if n >= 10:
break
print(n)
if __name__ == "__main__":
main()To run this Python code, simply execute it as a script.
Explanation:
Element Class: This defines the structure of an element in the list, containing a value and a pointer/reference to the next element.
List Class: This class manages the linked list and provides methods to add (
push) and iterate over all elements (all).gen_fib Function: This function generates an infinite sequence of Fibonacci numbers, which can be iterated until a specific condition is met (e.g., values less than 10).
main Function:
- Creates a list and pushes some elements into it.
- Iterates over the list elements and prints each one.
- Collects all elements of the list into a Python list and prints them.
- Generates Fibonacci numbers and prints them until a value reaches 10.
This translated Python version makes use of Python’s generator functions (yield) to replicate the iterator behavior.