Is it possible to extract the last token from a list of space separated tokens? LAST_TOKEN(a b) // expands to b LAST_TOKEN(blah blah b) // expands to b LAST_TOKEN(* & b) // expands to b Roman Perepelitsa.
On Mon, Nov 28, 2011 at 5:18 AM, Roman Perepelitsa <roman.perepelitsa@gmail.com> wrote:
Is it possible to extract the last token from a list of space separated tokens?
AFAIK, it depends. If the preceding tokens are known a priory and do not contain non-alphanumeric symbols, yes. Otherwise, no.
LAST_TOKEN(a b) // expands to b LAST_TOKEN(blah blah b) // expands to b
Yes but only if you know that `a` and `blah blah` are the only tokens that will ever be in front of b.
LAST_TOKEN(* & b) // expands to b
No because * and & are not alphanumeric. If this is your case, I can reply writing you the macros that can do this. HTH, --Lorenzo
2011/11/28 Lorenzo Caminiti <lorcaminiti@gmail.com>
On Mon, Nov 28, 2011 at 5:18 AM, Roman Perepelitsa <roman.perepelitsa@gmail.com> wrote:
Is it possible to extract the last token from a list of space separated tokens?
AFAIK, it depends. If the preceding tokens are known a priory and do not contain non-alphanumeric symbols, yes. Otherwise, no.
LAST_TOKEN(a b) // expands to b LAST_TOKEN(blah blah b) // expands to b
Yes but only if you know that `a` and `blah blah` are the only tokens that will ever be in front of b.
LAST_TOKEN(* & b) // expands to b
No because * and & are not alphanumeric.
If this is your case, I can reply writing you the macros that can do this.
Thanks for the reply, Lorenzo. Tokens can be anything in my case. I'll change the API of my macro to avoid the need for LAST_TOKEN. Roman Perepelitsa.
On Mon, Nov 28, 2011 at 6:28 AM, Roman Perepelitsa <roman.perepelitsa@gmail.com> wrote:
2011/11/28 Lorenzo Caminiti <lorcaminiti@gmail.com>
On Mon, Nov 28, 2011 at 5:18 AM, Roman Perepelitsa <roman.perepelitsa@gmail.com> wrote:
Is it possible to extract the last token from a list of space separated tokens?
AFAIK, it depends. If the preceding tokens are known a priory and do not contain non-alphanumeric symbols, yes. Otherwise, no.
LAST_TOKEN(a b) // expands to b LAST_TOKEN(blah blah b) // expands to b
Yes but only if you know that `a` and `blah blah` are the only tokens that will ever be in front of b.
LAST_TOKEN(* & b) // expands to b
No because * and & are not alphanumeric.
If this is your case, I can reply writing you the macros that can do this.
Thanks for the reply, Lorenzo.
Tokens can be anything in my case. I'll change the API of my macro to avoid the need for LAST_TOKEN.
Then one option would be to wrap the leading tokens within extra parenthesis: LAST_TOKEN( (a) b ) LAST_TOKEN( (blah blah) b ) LAST_TOKEN( (* &) b ) Or maybe (but I'm not 100% sure) even: LAST_TOKEN( (blah) (blah) b ) LAST_TOKEN( (*) (&) b ) This macro can be implemented (but depending on your application domain there might be better looking options). Let me know if you need me to send you a draft implementation of the macro above. HTH, --Lorenzo
participants (2)
-
Lorenzo Caminiti -
Roman Perepelitsa