On 2018-03-14, at 09:51:22, Charles Mills wrote:
> 1. Is there a machine instruction that will find one string within
> another? That given "Now is the time" and "is" would find the "is" and
> return a pointer to it? A machine instruction analog of Rexx POS?
>
> 2. Searching the PoOp for such an instruction led me to CUSE. It does
> not seem that CUSE could be used for this - is that correct? If I am reading
> CUSE correctly, then given "Now is the time", "All is well" and 2 or 3 would
> return the position of "is". Is my reading correct? What would that be good
> for? What would be a reasonable real-world use?
>
BTW, the classic technique is Boyer-Moore. But see:
https://en.wikipedia.org/wiki/String_searching_algorithm
This might easily be done in microcode. And I once coded a case-insensitive
variant of Boyer-Moore.
-- gil
