from __future__ import *

2008-03-08

Exploring Erlang @ C4[1] video

Filed under: erlang, mochiweb — bob @ 8:56 am

The video of the Exploring Erlang talk I gave at C4[1] last August is up on the interwebs! It only took seven months :)

Video:: http://rentzsch.com/c4/c41VideosAvailable
Slides and source:: http://bob.pythonmac.org/archives/2007/08/11/exploring-erlang-c41/

Comments (2)

2007-12-17

Printing floats with Erlang

Filed under: erlang, mochiweb — bob @ 10:37 pm

The float printing options that ship with Erlang all suck. You either don't have sufficient precision, or you have an extremely verbose representation:

1> io:format("~w ~.18g ~g ~s~n", [0.1234567, 0.1234567, 0.1234567, float_to_list(0.1234567)]).
0.123457 0.123456700000000003 0.123457 1.23456700000000002548e-01
2> io:format("~w ~.18g ~g ~s~n", [0.1, 0.1, 0.1, float_to_list(0.1)]).
0.100000 0.100000000000000006 0.100000 1.00000000000000005551e-01

mochiweb includes an implementation of the algorithm from the "Printing Floating-Point Numbers Quickly and Accurately" paper in the mochinum module (which is standalone, if you just want to use it without the rest of mochiweb):

3> io:format("~s~n", [mochinum:digits(0.1234567)]).
0.1234567
4> io:format("~s~n", [mochinum:digits(0.1)]).
0.1

Problem solved :)

Comments (0)

Using the mochiweb project skeleton

Filed under: erlang, mochiweb — bob @ 9:06 pm

A bit over a week ago we moved a slightly modified version of our project skeleton into the open source mochiweb repository, which gets you a start shell script, a skeleton application following (most of) the OTP paradigms, a Makefile, and a web server that serves static files out of priv/www.

The first thing you have to do is make sure mochiweb is built:

$ cd ~/src/mochiweb
$ make
(cd src;make)
make[1]: Nothing to be done for `all'.

After that you just run ./scripts/new_mochiweb.erl with the project name and destination (you can put a symlink of that script on your PATH somewhere).

$ ./scripts/new_mochiweb.erl mochidemo ~/src
...

Starting it is easy, just build with make and then run start.sh or start-dev.sh from ~/src/mochidemo. The only difference between the two at the moment is that start-dev.sh will poll for changes in ebin files and purge them automatically when they're updated. The default port is 8000 listening on all IPs and it's configured in src/PROJECT_sup.erl.

$ cd ~/src/mochidemo
$ make
...
$ ./start-dev.sh
...
=PROGRESS REPORT==== 17-Dec-2007::20:58:33 ===
         application: mochidemo
          started_at: nonode@nohost

1> http:request("http://127.0.0.1:8000/").
...
{ok,{{"HTTP/1.1",200,"OK"},
     [{"date","Tue, 18 Dec 2007 04:58:55 GMT"},
      {"server","MochiWeb/1.0 (Any of you quaids got a smint?)"},
      {"content-length","88"},
      {"content-type","text/html"}],
     "<html>\n<head>\n\n</head>\n<body>\nMochiWeb running.\n</body>\n</html>\n"}}

As far as deployment goes, it's a convenience that mochiweb makes a symlink to itself as PROJECT/deps/mochiweb-src so that the start scripts can find it and put them in your code path. You'll probably want to put a full copy of mochiweb in its place, use a svn:external (which is what we do right now), or manage the mochiweb dependency by some other means.

Comments (0)

2007-11-07

mochiweb - another faster web server

Filed under: erlang, mochiweb — bob @ 9:39 pm

mochiweb is finally well on its way to becoming a proper open source project, thanks to Matthew Dempsky. We've got a mochiweb project on google code and a mochiweb group on google groups.

Similarly interesting is that iserve is now turning into something more useful. iserve and mochiweb are pretty much the same thing under the hood, but mochiweb exposes a different API (which I find to be nicer, but I designed it) and supports more of the HTTP protocol. They both (ab)use inets' {packet, http} mode and they're both very minimal.

Here's a mochiweb version of the minimal example that Tobbe gave for iserve:

-module(mochiweb_demo).
-export([mochiweb_request/1, start/1]).

start(Port) ->
    mochiweb_http:start([{port, Port}, {loop, {?MODULE, mochiweb_request}}]).

mochiweb_request(Req) ->
    Req:ok({"text/html",
    <<"<!DOCTYPE html PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\">
        <html>
        <head><title >Welcome to mochiweb</title></head>
        <body>
            Hello
        </body>
        </html>">>}).

Comments (1)

from future import *
Kailash and Friends Kailash Kher Kaipa

2008-03-08

Exploring Erlang @ C4[1] video

2007-12-17

Printing floats with Erlang

Using the mochiweb project skeleton

2007-11-07

mochiweb - another faster web server

Links

from __future__ import * Kailash and Friends Kailash Kher Kaipa

2008-03-08

Exploring Erlang @ C4[1] video

2007-12-17

Printing floats with Erlang

Using the mochiweb project skeleton

2007-11-07

mochiweb - another faster web server

Links

from future import *
Kailash and Friends Kailash Kher Kaipa