wxerlang

Is there any comprehensive tutorial out there about wxerlang? Or do i
have to go the wxWidget route?
The only thing i could find is http://wxerlang.dougedmunds.com .
Any idea?

State in webmachine

crypto:md5/1 vs openssl md5

Performance difference between string and binary data when queried in mnesia?

I have a table to have >1.5 million records in it.

-record(hosts, {hostname,  flags, catmask}).
application:start(mnesia).
mnesia:create_table(hosts, [{ram_copies, [node()]}, {attributes, 
record_info(fields, hosts)}]).

mnesia:dirty_select(hosts, [{#hosts{hostname='$1', _='_'}, [{'=<', '$1', 
SearchParam}], ['$_']}]).

Is there any significant performance difference between: SearchTerm = 
"facebook.com", and SearchTerm = <<8,"facebook", 3, "com", 0>>, ?

Thanks and egger to hear some responses...

--

-- 
-brian

Post and query string parameter validation library?

Hello. I'm relatively new to Erlang programming. My project is an backend
API for a JSON based webservice.

I'm looking for a library which can take a proplist in form of

[{"param_name", "value"}, ...]

and validate the values against a set of specifications for the
parameters.  

I'm pretty open to how specifications are declared or passed.

(The proplist comes from mochiweb post_params() or query_params() calls.)

Before I go reinvent the wheel, I thought I'd ask if there's something
already
out there that does this.

Thanks.

Mark

Mark Allen
Sr. Software Developer
Alert Logic, Inc.
mallen <at> alertlogic.com
Security € Compliance € Cloud

Character encoding and the Windows command line

Here is a simple test program:

   -module(test).
   -export([test/0]).
   test() -> io:format("Args were ~w~n", [init:get_plain_arguments()]).

If I invoke this on Ubuntu, with the command line:

   $ erl -run test test -- 新

I get:
   Args were [[230,150,176]]

which is the UTF-8 encoding of the character I gave (\u65b0, "new, 
recent, fresh, modern"). Great!

Then I try it on my Chinese language copy of Windows XP:

   C:\>"c:\Program Files\erl5.9\bin\erl" -run test test -- 新
   Args were [[208,194]]

Huh. That's (it turns out) encoded in GB18030. Which would appear to be 
the encoding used by Windows. Better yet, if I try the same thing on a 
UK copy of Windows it tries to use an encoding which can't handle 
Chinese characters.

So this sucks. I would like my application internally to use all UTF-8, 
all the time. It would appear that I can use the Windows command "chcp" 
to detect which encoding Windows will impose on me, then try to use 
erlang-iconv or something to sort myself out but:

a) This seems hideous; does anyone have a better way? (Sorry, "don't 
support Windows" is not a better way).

b) It gets worse: suppose my application is installed to a path which 
includes non-ASCII characters, and we use "-pa" to tell erl.exe where 
that is...

In that case we *still* pass through the path in GB18030 or whatever, 
and erl.exe fails to even find it as it expects UTF-8. Is there any 
solution to this *at all*?

Cheers, Simon

--

-- 
Simon MacMullen
RabbitMQ, VMware
_______________________________________________
erlang-questions mailing list
erlang-questions <at> erlang.org
http://erlang.org/mailman/listinfo/erlang-questions

is empty catch statement possible?

Hello,
consider this macro:

-define(silent(Level, Expr), (fun() ->
                __Lager_OldLevel = lager:get_loglevel(lager_console_backend),
                try 
                    fun() -> Expr end 
                catch
                    throw:'$__should_never_be_thrown' -> ok
                after
                    leger:set_loglevel(lager_console_backend, __Lager_OldLevel)
                end 
        end)()).

1) does it do what I expect? I want log level to be restored in _any_ case.
2) Is there a way to avoid the stub throw:Atom statement?

Thanks
Motiejus

How to convert UTF8 string to lowercase?

Hello,

In the string module no word is mentioned about Unicode. Can to_lower/1
be used to covert Utf8 encoded string to lowercase?

I remember I read somewhere that these functions are not Unicode safe.
So what else can be used?

Regards,

Martin

searching in an ETS table for substring

Hello,

Is it possible to search in an ETS table for a key that starts with
certain characters?
Something equivalent to:

SELECT * FROM table WHERE name LIKE 'some%'

I read the documentation for select/2 and it says we can use as guards
functions as is_* and the like.

Best regards,

Martin

Starting erl with unicode hostname

beginner: How make reltool handle multiple versions of libs?

Greetings,

The Erlang/OTP installation I use(*) overwhelms reltool(**). At least
that is what I think, since dialyzer gave me a similar error until I
switched to use "-r lib/*-0".
Can I tell reltool to ignore all but the *-0 versions, too?

bengt

(*)
lib/appmon-0
lib/appmon-2.1.12
lib/appmon-2.1.13
lib/asn1-0
lib/asn1-1.6.14
lib/asn1-1.6.14.1
lib/asn1-1.6.15
lib/asn1-1.6.16
...
lib/wx-0.98.8
lib/wx-0.98.9
lib/wx-0.99
lib/xmerl-0
lib/xmerl-1.2.10
lib/xmerl-1.2.5
lib/xmerl-1.2.6
lib/xmerl-1.2.7
lib/xmerl-1.2.8
lib/xmerl-1.2.9

(**)
4> {ok, Pid} = reltool:start_server([{config, "reltool.config"}]).
{ok,<0.51.0>}

=CRASH REPORT==== 9-Feb-2012::14:43:17 ===
  crasher:
    initial call: reltool_server:init/1
    pid: <0.51.0>
    registered_name: []
    exception exit: "hipe: Application version clash. Multiple
directories contains version \"3.8.1\"."
      in function  reltool_server:do_init/1
      in call from reltool_server:init/1
    ancestors: [<0.47.0>]
    messages: []
    links: [<0.47.0>]
    dictionary: []
    trap_exit: false
    status: running
    heap_size: 317811
    stack_size: 24
    reductions: 1762187
  neighbours:
    neighbour: [{pid,<0.47.0>},
                  {registered_name,[]},
                  {initial_call,{erlang,apply,2}},
                  {current_function,{shell,eval_loop,3}},
                  {ancestors,[]},
                  {messages,[]},
                  {links,[<0.26.0>,<0.51.0>]},
                  {dictionary,[]},
                  {trap_exit,false},
                  {status,waiting},
                  {heap_size,2584},
                  {stack_size,7},
                  {reductions,5367}]
** exception error: "hipe: Application version clash. Multiple
directories contains version \"3.8.1\"."