OpenEuphoria

Re: Parsing a Dice Roll String

• Posted by "Christian Cuvier" <Christian.CUVIER at agriculture.gouv.fr> Aug 05, 2004
• 433 views

> 
> posted by: cklester <cklester at yahoo.com>
> 
> Christian Cuvier wrote:
> 
>>>Subject: Parsing a Dice Roll String
>>>posted by: cklester <cklester at yahoo.com>
>>>I'm writing a die roller and need to be
>>>able to parse a dice function string.
>>>Some examples:
>>>   3d6+5 (roll 6-sided die 3 times, add 5 to sum)
>>>   4d6-Lowest (roll 6-sided die 4 times, discard lowest die)
>>>   4d6-Highest (roll 6-sided die 4 times, discard highest die)
>>>   2d10*3-3d4 (roll 10-sided die twice, multiply by 3, then subtract
>>>               the result of rolling a 4-sided die three times)
>>>   5d12/10 (roll 12-sided die five times, divide result by 10)
>>>
>>>The current roller and a die-roll graphing program
>>>can be found here: <a
>>>href="http://www.cklester.com/euphoria/">http://www.cklester.com/euphoria/</a>
>>
>>Well, I'd expect Matt's matheval.e to be able to handle this with minor text 
>>translation.
>>My understanding of your pb is: parse a string like roll ::=
>>({<number>d<sides>[<operation>(roll | <reference> |
>><constant>])[<operation>])+
>>
>>where <reference is any of "Lowest" or "Highest" (any more?).
>>What's to be stored in list_Rolls? The roll outcome?
> 
> 
> Yes, along with the dice forumla.
> 
> 3 d6
> 17 3d6
> etc...
> 
> 
>><number> and <sides> are positive integers, <constant> is an atom..
>><operation> is any of +-*/ (any more?)
>>Did I get it?
> 
> 
> I think so! Now, where's the code for it, Parisian? :D
> 
> I think simplified, it can be written like:
> 
> (<number>d<sides>)+(<number>d<sides>|<constant>)...
> 
> Where + is any operator and <constant> is "Highest," "Lowest,"
> an actual number, or whatever other value I can come up with to
> modify the roll.
> 
This is the issue.
First off, are things like "4d(3d6-Highest)" allowed (perform 4 times the roll 
described inside the inner parentheses)?
Second, "would 4d6-Highest-Highest" be legal?
If so, would it mean "4d9-2*Highest" or "4d6 and remove the two highest 
outcomes, adding up the rest"?
Should we parse '6d6-H3" (remove third highest individual outcome)?
Then, wht about "6d6-3L" (remove the three lowest individual oitcomes)?

I may have other questions too...
 From Matt's reaction, and after a closer look at Kat's strtok, the latter is 
probably a better route to go.

I may start coding this WE if I get all questions answered before Friday 
17:00UTC. And, you know the kind of nasty questions that can arise when one 
starts coding :D

CChris