----------------------------------------------------------------
--
-- dice.lua
--
-- Copyright (C) 2002 Ian King
-- All Rights Reserved.
--
-- Redistribution and use in source and binary forms, with or without
-- modification, are permitted provided that this entire copyright notice
-- is duplicated in all such copies.
--
-- This software is provided "as is" and without any expressed or implied
-- warranties, including, without limitation, the implied warranties of
-- merchantibility and fitness for any particular purpose.
-- 
----------------------------------------------------------------

-- salt the random number generator from the date and time
math.randomseed(tonumber(os.date("%m%d%H%M%S")))

-- make a nice module

dice = {}

-- coin flipper

function dice.FlipCoin(flips)
    local sum = 0, i
    
    flips = flips or 1 -- if argument missing flip once
    
    for i = 1, flips do
        sum = sum + math.random(0,1)
    end

    return sum
end

-- roll some dice

function dice.Roll(rolls, sides)
    local sum = 0, i
    
    for i = 1, rolls do
        sum = sum + math.random(sides)
    end
    return sum
end

-- Create a function to evaluate expressions like "3d4 + 5D100 - 1"

function dice.DiceFunction(str)
    assert(str ~= "", "Dice String Empty")
    return loadstring("return "..string.gsub(str, "(%d+)[dD](%d+)", "dice.Roll(%1, %2)"), "dice.DiceFunction")
end


-- The End -----------------------------------------------------

-- vvvvvvvvvvvvvvvvvvvv Cut Here vvvvvvvvvvvvvvvvvvvvvvv
-- example code

Attrib = dice.DiceFunction("3d6")
Attack = dice.DiceFunction("10+1d20+3D8")
Complex = dice.DiceFunction("(3d7 / 3.14159) + Attack()")

function hit()
    if Attack() >= 35 then
        return "Hit"
    else
        return "Missed"
    end
end

print("One Hundred Coins", dice.FlipCoin(100))
print("One Hundred Coins", dice.FlipCoin(100))
print("One Hundred Coins", dice.FlipCoin(100))
print("One Coin", dice.FlipCoin(1))
print("One Coin", dice.FlipCoin())   -- one flip if no argument

print("str", Attrib())
print("int", Attrib())
print("dex", Attrib())
print("Attack", hit())
print("Attack", hit())
print("Attack", hit())
print("Attack", hit())

print("Complex", Complex())
print("Complex", Complex())
print("Complex", Complex())
print("Complex", Complex())
print("Complex", Complex())

-- ^^^^^^^^^^^^^^^^^^^^ Cut Here ^^^^^^^^^^^^^^^^^^^^^^^