lua-users home
lua-l archive

[Date Prev][Date Next][Thread Prev][Thread Next] [Date Index] [Thread Index]


2014-03-05 0:58 GMT+02:00 Pierre-Yves Gérardy <pygy79@gmail.com>:

> - %f[charset], the undocumented frontier pattern, which is a bit too
> long to describe here.

Since this is not the first post of 2014 in which the poster alleges
that the frontier pattern is undocumented, here is an extract from
the Lua 5.2 reference manual, already present in 5.2.2 if not before.

`%f[set]`, a frontier pattern; such item matches an empty string at
any position such that the next character belongs to set and the
previous character does not belong to `set`. The set `set` is
interpreted as previously described. The beginning and the end of the
subject are handled as if they were the character '\0'.