April 1997
Intermediate to advanced
240 pages
5h 56m
English
Content preview from Writing GNU Emacs ExtensionsBecome an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
The Profiler
Profiling a program is the process of figuring out how much time different parts of it take to run, presumably in a quest to make it more efficient. Barry Warsaw has written an ingenious package for profiling Emacs Lisp called ELP.
Like Edebug, ELP relies on functions being "instrumented." This is done with the command elp-instrument-function, which prompts for a function name. There's also elp-instrument-package, which prompts for a prefix. Any existing functions whose names begin with the given prefix will get instrumented.
Functions are uninstrumented with elp-restore-function and elp-restore-all.
To use ELP, simply run your program after instrumenting the functions you wish to profile. Profiling data will accumulate silently. When you're ready to see the results so far, run the command elp-results. A buffer will appear, showing, for each profiled function, the number of times it was called, the total time spent in the function, and the average time per call.
Use elp-reset-function to set a function's call-count and elapsed-time counters back to zero; elp-reset-all does this for all profiles functions.
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.