from typing import Dict


def build_dict(f_name: str) -> Dict[str, str]:
	"""
	builds a dictionary mapping builtins to their descriptions from the passed
	in file.

	Args:
		f_name : name of file containing descriptions of builitins

	Returns:
		dict{str: str}:
			maps builtins to their descriptions
	"""
	desc_dict = {}
	lens = []
	with open(f_name, "r") as descriptions:
		for i, line in enumerate(descriptions):
			ln_1, ln_2 = line.split(" : ")
			ln_2 = ln_2.replace("\n", "")
			desc_dict.update({ln_1: ln_2})
	return desc_dict