Timeline for Test if token is a control sequence
Current License: CC BY-SA 3.0
6 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jul 15, 2017 at 14:55 | history | edited | David Carlisle | CC BY-SA 3.0 | Fixing a site bug of disappearing double backslashes: https://tex.meta.stackexchange.com/questions/7168/double-backslashes-disappear-from-code |
| Jun 23, 2011 at 22:21 | comment | added | egreg | @Bruno: it all depends on the use Martin wants to make of this test and what he expects the argument to be. Of course one can devise tricky input to defy any attempt to build the test in the most general way; but normal input, in many cases, is just normal input. | |
| Jun 23, 2011 at 21:33 | comment | added | Bruno Le Floch | it depends on your definition of borderline case. A very weak form of the test would be \ifcat$\expandafter\@gobble\string#1$ (with the relevant \@firstoftwo and \@secondoftwo), if we don't care about spaces, and the case where \escapechar is 32 or non-printable. | |
| Jun 23, 2011 at 19:27 | comment | added | egreg | @Bruno: that's what I suspected. If one doesn't need to cope with borderline cases, \ifcat may be sufficient. | |
| Jun 23, 2011 at 18:36 | comment | added | Bruno Le Floch | It is not possible to have a purely expandable solution: \escapechar=-1\let\*=* makes * and \* indistinguishable expandably, except by delimited macro arguments (but you can't have that for all characters). Same problem with active characters. | |
| Jun 23, 2011 at 15:02 | history | answered | egreg | CC BY-SA 3.0 |