Re: Number parsing with checks

On 13/10/2024 12:54 am, Ruvim wrote:

On 2024-10-12 05:45, dxf wrote:

The basics:
>
: .BAD ( -- )  cr ." Invalid item"  .abort ;
>
: ZE? ( x -- )  if .bad then ;     \ abort if non-zero
: NZ? ( x -- )  0= ze? ;           \ abort if zero

 
Typically, if word name ends with a question mark, the first (top) output parameter of the word is a *flag*. And it's true for all standard words. (though, opposite is not true)

It's rather similar.

ZE? NZ?  destructively tests TOS
?ZE ?NZ  non-destructively tests TOS

Only difference is test and action are rolled into the one function.