Re: [EXTERN] Re: Definition of tokens in GP language
Bill Allombert <[email protected]> Fri, 24 Oct 2025 23:32:18 +0200
| Newsgroups | gmane.comp.mathematics.pari.devel |
|---|---|
| Message-ID | <aPvwYluanQUOE7wG@seventeen> |
On Fri, Oct 24, 2025 at 09:59:38PM +0200, Hong-Phuc Bui wrote: > Hi Bill, > > I took a look at the function. It is not really long, but I'm not sure about complexity: > Is it possible to recognize all tokens of GP by using regular express? Strictly speaking it is not possible using regex due to ambiguities. For example 3!=6 is 3 != 6 (3 tokens) while 3!==6 is 3 ! == 6 (4 tokens) and 3!===6 is 3 ! === 6 (4 tokens) There are other corner cases, depending how you define a token. Note that all spaces are removed before parsing so for example a ! = b is a != b (3 tokens) Cheers, Bill.