[RFC] API change in ngx.re: returning an error string intead of throwing exceptions

agentzh · 2013-03-18T12:23:31+00:00

Hello! On Sun, Mar 17, 2013 at 6:36 PM, Matthieu Tourne wrote: > How would be the best way to have an at_time function that would execute > after a gi...

[RFC] API change in ngx.re: returning an error string intead of throwing exceptions

agentzh

Hello!

I've just pushed a commit to ngx_lua's "ngx-re-no-exceptions" branch,
which eliminated almost all the Lua exceptions in the ngx.re API by
returning an extra string describing the error:

    https://github.com/chaoslawful/lua-nginx-module/commit/3ea32c9

To quote the commit log: "api-change: the ngx.re.match, ngx.re.gmatch,
ngx.re.sub, and ngx.re.gsub functions used to throw Lua exceptions
aggressively for all the error conditions; now they return an
additonal string describing the error for almost all common errors
instead of throwing exceptions, including pcre compile-time and
exec-time failures. thanks Matthieu Tourne for requesting this
change."

The trend in the ngx_lua's Lua API design is to eliminate Lua
exceptions because pcall and xpcall are expensive and also cumbersome
to use.

Comments welcome!

Thanks!
-agentzh

brian

On Mon, Mar 18, 2013 at 12:23 AM, agentzh <age...@gmail.com> wrote:
> The trend in the ngx_lua's Lua API design is to eliminate Lua
> exceptions because pcall and xpcall are expensive and also cumbersome
> to use.

+1

I'm not a big fan of using exceptions for error handling, in general,
so this is good news.

--Brian