def multiinsertLR_starred_and_co(new, oldL, oldR, l, col):
"""Inserts new to the left of `oldL` and to the right of `oldR`.
NB: Uses a collector func to gather new list and count L, R inserts
"""
if is_null(l):
return col(quote(), 0, 0)
if is_atom(car(l)):
if is_eq(car(l), oldL):
return multiinsertLR_starred_and_co(
new, oldL, oldR, cdr(l), lambda newl, L, R: col(
cons(new, cons(oldL, newl)), add1(L), R))
if is_eq(car(l), oldR):
return multiinsertLR_starred_and_co(
new, oldL, oldR, cdr(l), lambda newl, L, R: col(
cons(oldR, cons(new, newl)), L, add1(R)))
return multiinsertLR_starred_and_co(
new, oldL, oldR, cdr(l),
lambda newl, L, R: col(cons(car(l), newl), L, R))
return multiinsertLR_starred_and_co(
new, oldL, oldR, car(l),
lambda carnl, carL, carR: multiinsertLR_starred_and_co(
new, oldL, oldR, cdr(l), lambda cdrnl, cdrL, cdrR: col(
cons(carnl, cdrnl), add(carL, cdrL), add(carR, cdrR))))
def _is_atom(x):
"""Asks if atom, checks for primitives and non-primitives as well."""
if is_atom(x): return True
if is_null(x): return False
if is_eq(car(x), quote("primitive")): return True
if is_eq(car(x), quote("non-primitive")): return True
return False
def is_pair(l):
"""Asks if `l` is in fact a `pair`."""
if _or(is_atom(l), _or(is_null(l), is_null(car(l)))):
return False
if is_null(cdr(cdr(l))):
return True
return False
def leftmost(l):
"""Returns the leftmost atom from the list `l`."""
if is_null(l):
return quote()
elif is_atom(car(l)):
return car(l)
else:
return leftmost(car(l))
def no_nums(l):
"""Remove all the numbers in the list `l`."""
if is_null(l):
return quote()
elif is_atom(car(l)):
if is_number(car(l)):
return no_nums(cdr(l))
else:
return cons(car(l), (no_nums(cdr(l))))
else:
return cons(no_nums(car(l)), no_nums(cdr(l)))
def occur_starred(a, l):
"""Returns the the number of occurrences of `a` in `l`."""
if is_null(l):
return 0
elif is_atom(car(l)):
if is_eq(car(l), a):
return add1(occur_starred(a, cdr(l)))
else:
return occur_starred(a, cdr(l))
else:
return add(occur_starred(a, car(l)), occur_starred(a, cdr(l)))
def rember_starred(a, l):
"""Removes all occurences of `a` in `l`.
NB: `l` is not guaranteed to be a lat
"""
if is_null(l):
return quote()
if is_atom(l):
if is_eq(car(l), a):
return cdr(l)
return cons(car(l), rember_starred(a, cdr(l)))
return cons(rember_starred(a, cons(l)), rember_starred(a, cdr(l)))
def is_member_starred(a, l):
"""Asks if `a` is a member of `l`.
NB: `l` is not guaranteed to be a lat
"""
if is_null(l):
return False
if is_atom(car(l)):
if is_eq(a, car(l)):
return True
return is_member_starred(a, cdr(l))
_or(is_member(a, car(l)), is_member(a, cdr(l)))
def all_nums(l):
"""Return all numbers from list `l`."""
if is_null(l):
return quote()
elif is_atom(car(l)):
if is_number(car(l)):
return cons(car(l), all_nums(cdr(l)))
else:
return all_nums(cdr(l))
else:
return cons(all_nums(car(l)), all_nums(cdr(l)))
def insertR_starred(new, old, l):
"""Inserts `new` to the left of `old`, if `old` found in `l` for every occurrence."""
if is_null(l):
return quote()
elif is_atom(car(l)):
if is_eq(car(l), old):
return cons(new, cons(old, insertR_starred(new, old, cdr(l))))
else:
return cons(car(l), insertR_starred(new, old, cdr(l)))
else:
return cons(insertR_starred(new, old, car(l)),
insertR_starred(new, old, cdr(l)))
def evens_only_and_co(l, col):
"""Collects, evens, the multiplication of evens and addition of odds."""
if is_null(l):
return col(quote(), 1, 0)
if is_atom(car(l)):
if is_even(car(l)):
return evens_only_and_co(
cdr(l), lambda evens, p, s: col(cons(car(l), evens),
multiply(car(l), p), s))
return evens_only_and_co(
cdr(l), lambda evens, p, s: col(evens, p, add(car(l), s)))
return evens_only_and_co(
car(l), lambda car_evens, carp, cars: evens_only_and_co(
cdr(l), lambda cdr_evens, cdrp, cdrs: col(
cons(car_evens, cdr_evens), multiply(carp, cdrp),
add(cars, cdrs))))
def expression_to_action(exp):
"""Converts an `exp` to an action."""
if is_atom(exp):
return atom_to_action(exp)
def list_to_action(exp):
"""Converts `exp` to `action, assuming `exp` is `list`."""
if is_atom(car(e)):
if is_eq(car(e), quote("quote")):
def is_else(x):
"""Asks if `x` is an else statement."""
if is_atom(x):
return is_eq(x, quote("else"))
return False