Answer Happy

The below program is in Python. Request conversion to
Haskell.
import sys
def get_primes(max_number):
""" Computes and returns all prime numbers up to
max_number. """
primes = []
for value in range(2, max_number + 1):
is_prime = True
for prime in primes:
if value % prime ==
0:
is_prime =
False
break
if is_prime:

primes.append(value)
return primes
def goldbach(value):
""" Returns a list of integer such that for each p in
the list,
p + q = value, p <= q, and both p
and q are primes. """
result = []
if value >= 4 and value % 2 == 0:
primes = get_primes(value)
for prime in primes:
if prime > value /
2:
break
difference = value -
prime
if difference in
primes:

result.append(prime)
return result
def main():
""" Entry point of the program. """
data = []
if len(sys.argv) > 1:
for filename in sys.argv[1:]:

data.extend(readfile(filename))
else:
data = (3, 4, 14, 26, 100)
for value in data:
print_goldbach(value,
goldbach(value))
def print_goldbach(value, prime_list):
""" Given the value of n and the output of
goldbach(value),
prints out the result to the screen.
"""
if not prime_list:
print('We found no Goldbach pairs for
%d.' % value)
else:
print('We found %d Goldbach pair(s) for
%d.' %
(len(prime_list),
value))
for prime in prime_list:
difference = value -
prime
print('%d = %d + %d' %
(value, prime, difference))
print('')
def readfile(filename):
""" Reads and returns data from a file,
we assume no problem on opening and
reading from the file. """
data = []
file_handle = open(filename)
for line in file_handle:
data.append(int(line))
file_handle.close()
return data
main() # Invoke the main program.