def integer(self, i):
if i < 0: return (None, -1)
# sequence of digits, possibly preceded by minus sign
(v, j) = self.raw(i)
if j >= 0:
if (len(v) > 0 and v.isdigit()) or \
(len(v) > 1 and v[0] == '-' and v[1:].isdigit()):
n = int(v)
return (ast.NumSxp(n), j)
return (None, -1)
def primoplus(args):
assert (len(args) == 2)
v1 = args[0]
v2 = args[1]
assert (isinstance(v1, ast.NumSxp) and isinstance(v2, ast.NumSxp))
return ast.NumSxp(v1.number + v2.number)