h/plugins/dice.py

65 lines
1.9 KiB
Python

"""
dice.py: written by Scaevolus 2008, updated 2009
simulates dicerolls
"""
import re
import random
from util import hook
whitespace_re = re.compile(r'\s+')
valid_diceroll_re = re.compile(r'^[+-]?(\d+|\d*d(\d+|F))([+-](\d+|\d*d(\d+|F)))*$',
re.I)
sign_re = re.compile(r'[+-]?(?:\d*d)?(?:\d+|F)', re.I)
split_re = re.compile(r'([\d+-]*)d?(F|\d*)', re.I)
def nrolls(count, n):
"roll an n-sided die count times"
if n < 2: # it's a coin
if count < 5000:
return sum(random.randint(0, 1) for x in xrange(count))
else: # fake it
return int(random.normalvariate(.5*count, (.75*count)**.5))
else:
if count < 5000:
return sum(random.randint(1, n) for x in xrange(count))
else: # fake it
return int(random.normalvariate(.5*(1+n)*count,
(((n+1)*(2*n+1)/6.-(.5*(1+n))**2)*count)**.5))
@hook.command('roll')
@hook.command
def dice(inp):
".dice <diceroll> -- simulates dicerolls, e.g. .dice 2d20-d5+4 roll 2 " \
"D20s, subtract 1D5, add 4"
spec = whitespace_re.sub('', inp)
if not valid_diceroll_re.match(spec):
return "Invalid diceroll"
sum = 0
groups = sign_re.findall(spec)
for roll in groups:
count, side = split_re.match(roll).groups()
count = int(count) if count not in " +-" else 1
if side.lower() == "f":
if count > 0:
sum += nrolls(count, 3) - 2 * count
else:
sum -= nrolls(count, 3) + 2 * count
elif side == "":
sum += count
else:
side = int(side)
try:
if count > 0:
sum += nrolls(count, side)
else:
sum -= nrolls(abs(count), side)
except OverflowError:
return "Thanks for overflowing a float, jerk >:["
return str(sum)