OpenEuphoria

Re: Procedures and Parameters

• Posted by Irv Mullins <irv at ELLIJAY.COM> Jul 26, 1999
• 326 views

On Mon, 26 Jul 1999, you wrote:
> All,
>
> The problem here is this, if define the Look procedure in the
> following manner to handle input such as look
>
> global procedure Look()
>     ..........
>     puts(You look.......
> end procedure
>
> and the user enters   look vase   then the program aborts
> with the following message:
>
> Syntax error - expected to see possibly ')', not a variable
>
> If I define the Look procedure in the following manner
> to handle input such as     look vase
>
> global procedure Look( sequence Obj)
>     ...........
>     puts(You look........
> end procedure
>
> and the user enters   look   then presses return the
> program aborts with the following message:
>
> Look() needs 1 arguments, not 0

> Is there a better more efficient way to handle this?
>
I think you may as well go ahead and write a command parser, you will be
calling it from all over your program. That way, one function can handle valid
and invalid inputs appropriately. You'll need a small dictionary of nouns and
verbs, and set up some simple syntax rules:  i.e. "vase look" could return a
"sorry, don't know how to vase",  while "look vase" returns "You are looking
at",  & "a blue vase"....  You may also want to set up tables of attributes -
so "take house" returns a smart alek remark, rather than "you are carrying a
vase and a house"....

Irv