Re: Scheme 102

[rm]

On Wed, Nov 28, 2001 at 11:45:58AM -0600, address@hidden wrote:
> 
> hello,
> 
> is it possible to dynamically discover the number of parameters to a
> function?
> 
> say you read a function name + parameters from stdin or from user input.
> how can i check the number of required parameters have been supplied
> without calling the function. this would avoid aborting when 2 param were
> supplied instead of 3 e.g
> 
> ...read "f 1 2 3" from the command line
> ...fname is "f"
> ...list-of-params is "1 2 3"
> 
> (define (f x y) (+ x y))
> 
> ((eval (string->symbol fname)) list-of-params)
> 
> ERROR: Wrong number of arguments to #<primitive-procedure f>
> 
> any idea ?


Would this be what you are looking for?

| bash-2.05$ guile
| guile> (arity display)ay)
| 1 required and 1 optional argument.
| guile> (arity map)    
| 2 or more arguments.
| guile> 


HTH  Ralf Mattes
> thx!
> 
> 
> 
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