From: Will Shattuck <willshattuck@...>
Date: 2006-01-07T05:42:32+09:00
Subject: Re: [QUIZ] Dice Roller (#61)

forgive my ignorance... BNF?

w


On 1/6/06, Matthew Moss <matthew.moss.coder@gmail.com> wrote:
> > I would appreciate the full BNF, please.
>
> Okay, this is what I've done in my current version that takes care of basic
> precedence and associativity.
>
> INTEGER = /[1-9][0-9]*/
>
> expr: fact
>     | expr '+' fact
>     | expr '-' fact
>
> fact: term
>     | fact '*' term
>     | fact '/' term
>
> term: unit
>     | [term] 'd' dice
>
> dice: '%'
>     | unit
>
> unit: '(' expr ')'
>     | INTEGER
>
>
> Actually, this is slightly different than my current version, which after
> reexamining to extract this BNF, I found a minor error (in handling of the
> term rules and handling of the optional arg). My own code has a morphed
> version of this BNF in order to code up a recursive descent parser, but this
> BNF shows one way to handle the precedence/association rules.
>
>


--
Will Shattuck  ( willshattuck.at.gmail.com )
Home Page:  http://www.thewholeclan.com/will

When you get to your wit's end, you'll find God lives there.