Bruce/bp
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Updated build

Browse Source
This commit is contained in:
Bruce Hill 2021-05-20 17:26:38 -07:00
parent f8b655dc4d
commit 8df68fa869
1 changed files with 18 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
bp.1
View File

@ -224,10 +224,26 @@ over instances of \f[I]skip\f[R] (e.g.\ \f[B]\[ga]\[dq]..\[ga]\[dq] %
(\[ga]\[rs].)\f[R])
.TP
\f[B]<\f[R] \f[I]pat\f[R]
Just after \f[I]pat\f[R] (lookbehind)
Matches at the current position if \f[I]pat\f[R] matches immediately
before the current position (lookbehind).
Conceptually, you can think of this as creating a file containing only
the \f[I]N\f[R] characters immediately before the current position and
attempting to match \f[I]pat\f[R] on that file, for all values of
\f[I]N\f[R] from the minimum number of characters \f[I]pat\f[R] can
match up to maximum number of characters \f[I]pat\f[R] can match (or the
length of the current line upto the current position, whichever is
smaller).
\f[B]Note:\f[R] For fixed-length lookbehinds, this is quite efficient
(e.g.\ \f[B]<(100\[ga]x)\f[R]), however this could cause performance
problems with variable-length lookbehinds (e.g.\ \f[B]<(\[ga]x
0-100\[ga]y)\f[R]).
Also, it is not advised to use \f[B]\[ha]\f[R], \f[B]\[ha]\[ha]\f[R],
\f[B]\[u2005]*\[u2005]*,\f[BI]o\f[B]\f[BI]r\f[B]\[u2005]*\[u2005]*$\f[R]
inside a lookbehind, as they will match against the edges of the
lookbehind slice.
.TP
\f[B]>\f[R] \f[I]pat\f[R]
Just before \f[I]pat\f[R] (lookahead)
Matches \f[I]pat\f[R], but does not consume any input (lookahead).
.TP
\f[B]\[at]\f[R] \f[I]pat\f[R]
Capture \f[I]pat\f[R]