gmane.comp.lang.ruby.general

Re: Strange require behaviour

Joel Pearson — 2013-06-19T07:57:31

I found this about the "gem" command within IRB:

Kernel#gem
gem(gem_name, *version_requirements)
------------------------------------------------------------------------
     Adds a Ruby Gem to the $LOAD_PATH. Before a Gem is loaded, its
     required Gems are loaded. If the version information is omitted,
     the highest version Gem of the supplied name is loaded. If a Gem
     is not found that meets the version requirement and/or a required
     Gem is not found, a Gem::LoadError is raised. More information on
     version requirements can be found in the Gem::Version
     documentation.

     The gem directive should be executed before any require statements
     (otherwise rubygems might select a conflicting library version).

     You can define the environment variable GEM_SKIP as a way to not
     load specified gems. you might do this to test out changes that
     haven't been intsalled yet. Example:

       GEM_SKIP=libA:libB ruby-I../libA -I../libB ./mycode.rb

     gem:                 [String

Strange require behaviour

Damjan Rems — 2013-06-19T07:30:38

Why does gem 'bson_ext' work, but require 'bson_ext' does not. Ruby
1.9.3. Same on Windows or Linux.

C:\irb
irb(main):001:0> require 'bson_ext'
LoadError: cannot load such file -- bson_ext
        from
c:/Ruby193/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:36:in
`require'
        from
c:/Ruby193/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:36:in
`require'
        from (irb):1
        from c:/Ruby193/bin/irb:12:in `<main>'
irb(main):002:0> gem 'bson_ext'
=> true
irb(main):003:0>


by
TheR

Re: trying to load a .rb file in irb

Joel Pearson — 2013-06-19T06:40:22

I'd use
File.foreach( 'text.txt' ) {|line| puts line }

[ANN] Slide Show (S9) 2.0.0 Update - Command Suite Added - build,install,ls,new,etc.

Gerald Bauer — 2013-06-19T06:06:14

Hello,

  I've updated the slideshow gem, that is, version 2.0.0. What's new?

  I've added a git or gem like command suite. For example, to build
your slideshow use:

  $ slideshow build welcome.txt

  Fetching template packs has changed to slideshow install <MANIFEST>. Example:

  $ slideshow install impress.js

  or

  $ slideshow install
https://raw.github.com/slideshow-s9/slideshow-impress.js/master/impress.js.txt

  To list all install template packs and quick starter packs use:

  $ slideshow list  or slideshow ls

  And to create a quick starter sample use:

  $ slideshow new -t impress.js


  Note, all commands also let you use single-letter aliases e.g.

   build   -> b
   install -> i
   list    -> l or ls
   new     -> n
   about   -> a

  That's it. More info < at > http://slideshow-s9.github.io

 Questions? Comments? Cheers.

Re: trying to load a .rb file in irb

2013-06-19T05:37:09

Am 18.06.2013 23:27, schrieb Eric D.:


   File.open("text.txt").each {|line| puts line }

Never put a space between method name and '('.


BTW. When you figure it out by yourself, you should also include
      the solution in your "Never mind" post. In case other people
      have a similar problem.

Multimode error in 4.6.3

Bryan G. — 2013-06-19T02:17:21

I was not sure where to post this I have worked on this several days.
I posted the entire log from gnu radio and ./multimode.py in attached
txt
I think that 4.6.3 is not compatible or library mismatch "its a clean
install gnuradio-companion is working but ./multimode gives me this and
other errors
Im sorry if I posted this in the wrong place very new to Linux and
gnuradio

self.gr_multiply_const_vxx_2 = gr.multiply_const_vff((1.0 if
mh.get_mode_type(mode) == "FM" else 0.0))
  File
"/usr/local/lib/python2.7/dist-packages/gnuradio/gr/gnuradio_core_gengen.py",
line 9713, in multiply_const_vff

Bryan

Attachments:
http://www.ruby-forum.com/attachment/8525/Untitled_Document_1
http://www.ruby-forum.com/attachment/8526/Untitled_Document_1

Multimode error in 4.6.3

Bryan G. — 2013-06-19T02:10:23

I was not sure where to post this I have worked on this several days.
I posted the entire log from gnu radio and ./multimode.py in attached 
txt
I think that 4.6.3 is not compatible or library mismatch "its a clean 
install gnuradio-companion is working but ./multimode gives me this and 
other errors
Im sorry if I posted this in the wrong place very new to Linux and 
gnuradio

self.gr_multiply_const_vxx_2 = gr.multiply_const_vff((1.0 if 
mh.get_mode_type(mode) == "FM" else 0.0))
  File 
"/usr/local/lib/python2.7/dist-packages/gnuradio/gr/gnuradio_core_gengen.py", 
line 9713, in multiply_const_vff

Bryan

Attachments:
http://www.ruby-forum.com/attachment/8524/Untitled_Document_1

Re: getting the most out of Ruby

robin wood — 2013-06-18T23:09:36

Brandon W. wrote in post #1112804:

Got any resources you used to help get your head around all these?

Re: getting the most out of Ruby

robin wood — 2013-06-18T23:08:38

Stu wrote in post #1112800:

I really like Ruby's OO model and it is something that frustrates me 
whenever I have to switch to Python as it doesn't feel quite as nice. I 
did some smalltalk at uni so I think that may be why I'm drawn to it.

I do a lot of shell work so the regex stuff comes naturally luckily but 
it did take a lot of effort to learn in the first place.

It is the functional style stuff that I'm still getting my head around, 
I never really got lisp when they tried to teach it at uni.


I'm looking at the refactoring work to try to learn the more "Ruby" ways 
to do things rather than initially trying to write faster or tighter 
code.


Thanks

Re: Creating ruby script exe

Devin Christensen — 2013-06-18T22:55:33

Looks like there's an example in the docs:

You can detect whether OCRA is currently building your script by looking
for the ‘Ocra’ constant. If it is defined, OCRA is currenly building the
executable from your script. For example, you can use this to avoid opening
a GUI window when compiling executables:

   app = MyApp.new
   if not defined?(Ocra)
     app.main_loop
   end


On Tue, Jun 18, 2013 at 5:27 AM, Rochit Sen <lists< at >ruby-forum.com> wrote:

Re: trying to load a .rb file in irb

Eric D. — 2013-06-18T21:33:26

Never mind i figured it out. Thank you guys! Great forum!

Re: trying to load a .rb file in irb

Eric D. — 2013-06-18T21:27:17

The directory change worked! Thank you both for your help. One question 
though, when I try to load a text file from a program in ruby it says

undefined method `each' for "text.txt":String (NoMethodError).


My code looks like this:

File.open ("text.txt").each {|line| puts line}


Both the text.txt and the program loading it are in the same directory.

Any suggestions?

Re: getting the most out of Ruby

Brandon Weaver — 2013-06-18T19:59:51

The biggest jumping point for me is when I stopped trying to program Ruby
like C# and started programming Ruby like Ruby.

Coming from C land you have tendencies towards a lot of imperative
techniques, and Ruby is not solely imperative. Learning the functional side
of Ruby is essential to graduate into advanced topics.

Blocks, Lambdas, Closures, Metaprogramming, and Enumerables are the huge
topics. Master them and you'll see a huge difference.
On Jun 18, 2013 3:33 AM, "robin wood" <lists< at >ruby-forum.com> wrote:

Re: getting the most out of Ruby

Stu — 2013-06-18T19:40:43

Robin, If you look at ruby from a polyglot programmer view of the major
paradigms consider this. Ruby is essentially three major paradigms modeled
after three major programming languages, actually more but lets keep it
simple.

Ruby's object oriented is modeled after smalltalk; Though it's marketed as
python
Ruby's functional style is modeled after scheme lisp; Ruby programmers know
the value of everything, but the cost of nothing =)
Ruby's system programming is modeled after the procedural shell; Basically
the c programming language, awk, bourne shell, UNIX regular expressions Et
al. ; This is marketed as Perl( though the %{ literals } came from perl)

Though refactoring (i.e. less tokens == faster execution) is good to grok
and testing aids the practice and is definitely part of the software
development process it may be also useful to understand Ruby also from it's
ancestors which further reseach can be seen from languages and utilities
dating back to early days of computer science in the 1950's

Good luc

Re: Compare and sort one array according to another.

masta Blasta — 2013-06-18T18:51:56

Bartosz Dziewoński wrote in post #1112795:

Re: Compare and sort one array according to another.

Bartosz Dziewoński — 2013-06-18T18:36:51


I think that's for 100 000 repetitions of the test.

Re: Compare and sort one array according to another.

masta Blasta — 2013-06-18T17:46:36

Robert Klemme wrote in post #1112735:

This has been a great little learning exercise for me. I had never quite 
gotten how the sort_by method worked, and now reading it over again with 
the example it's perfectly clear.

I'm surprised at how slow the method is. In the benchmark, 1.24s for 10 
records...?? That's huge! The SQL query to fetch the records already 
sorted, as big and messy as it is, still only takes 10ms. I might have 
to stick with SQL on this one since for a Rails app response time is 
critical.

I'm certainly glad I came and asked for help about this.

Re: Timsort in Ruby

Roger Pack — 2013-06-18T16:15:47

Matthew Kerwin wrote in post #1112422:

(as a note, it would be interesting to benchmark both running time, 
which you have, and "number of compares requires" also).

I wonder if the timsort project itself has some benchmark test cases you 
could use.  I know it's supposed to work better with semi-sorted data, 
maybe try that.  Of course, with surprising results like these, it would 
be interesting to port ruby's sort into the python trunk/core and see if 
it makes Python faster there (and if so, to ask the Python and timsort 
people ...):)
-roger-

Re: Persistent value assign

Ebru Akagunduz — 2013-06-18T14:40:16

I had seen yaml when i search with google. But just i didn't want to use 
yaml :) I decided to write variable in a file, thanks :)

Re: Persistent value assign

Joel Pearson — 2013-06-18T13:48:30

If you want persistent storage you'll need to output the data into a 
file, and read the file at startup.
The usual method for this would be something like an internal database 
(SQlite?), or using YAML files. If it's something really simple you can 
just create a text file somewhere it won't be interfered with.

Re: Persistent value assign

2013-06-18T14:07:41

Am 18.06.2013 15:07, schrieb Ebru Akagunduz:

There are many possibilities: e.g. write to a file (as string),
convert into YAML and write to a file, use some database, ...


Here a simple example using YAML::Store, where the data is stored
in the file 'values.yml':


require 'yaml/store'
store = YAML::Store.new('values.yml')

# create variables with default values in local scope
value = 1
name = 'Fred'

# read old values if stored
store.transaction do
   value = store['value'] || value
   name  = store['name']  || name
end

puts "old:"
p value
p name
puts

# change variables
value += 1
name  = name.reverse.capitalize

puts "new:"
p value
p name

# store values
store.transaction do
   store['value'] = value
   store['name']  = name
end