Ruby on Rails Love-In

The Something Awful Forums > Discussion > Serious Hardware/Software Crap > The Cavern of COBOL > Ruby on Rails Love-In

Soup in a Bag: Dec 4, 2009

Jam2 posted:

I need to create a key for the first_letter. It doesn't exist when I do
code:
letters_and_words = Hash.new([])
Am I missing something?

Read up on Hash.new in the core docs. If you give the Hash a default object or block, that object will be used or that block evaluated whenever you reference a non-existent key.

Unfortunately there can be a problem using a default object:

code:

>> h = Hash.new([])
=> {}
>> h[:foo] # :foo doesn't exist as a key
=> []      # so the single default object is used
>> h[:bar] << 7
=> [7]     # same as above, the default object is used
>> h[:foo]
=> [7]

Instead you'd use the default block form:

code:

>> h = Hash.new {|hash, key| hash[key] = []}
=> {}
>> h[:foo] # default block is evaluated since :foo didn't already exist
=> []
>> h[:bar] << 7
=> [7]
>> h[:foo]
=> []

With the block form of Hash initialization, the body of Enumerable#each_group_by_first_letter can be written in three lines while still being very understandable.

Soup in a Bag fucked around with this message at 05:08 on Jun 17, 2011

# ¿ Jun 17, 2011 05:03

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# ¿ Apr 27, 2024 08:53

Soup in a Bag: Dec 4, 2009

Defghanistan posted:

Well I actually am choking on a ruby error, since chef is checking the .rb file against ruby syntax- so the powershell part of it is moot right now aside from the fact that it has to pass ruby syntax muster. I'll look into that, thanks.

I am sorry for the spam, but I cannot seem to find the error here. I double quoted and escaped the slashes, but now can't find any problems.

http://codepad.org/AgwDrLY5

You're still getting the same error? I'm guessing that this: "invalid multibyte char (US-ASCII)" is the important clue. Just looking at line 104 in your first paste (line 10 in your latest paste), it seems like the '-' in "-Type Directory" is bigger than your other '-'s. Maybe that's what it's complaining about?

# ¿ Jun 17, 2011 20:49

Soup in a Bag: Dec 4, 2009

There's String#empty?, but no NilClass#empty? method. If r.email is nil rather than an empty String you'll get that error.

# ¿ Jun 29, 2011 00:34

Soup in a Bag: Dec 4, 2009

Juz posted:

I'm trying to use that function to return the contents of a file from the FTP server into a variable rather than write it to a file. The comment for the function says "If localfile is nil, returns retrieved data" and it looks from the source like the intention is there to be able to do this, but I can't see how you can do this given that it sets localFile = File.basename(remotefile) in the argument list.

I thought I might be able to do gettextfile(my_remotefile, nil), but ruby complains about converting "nil" to a string.

Which version of Ruby are you using? That documentation link from your earlier post is for 1.9. In 1.8, #gettextfile doesn't have the option of not writing to a file and passing nil would result in the error you're getting.

e: But in 1.9 what you're attempting would work.

Soup in a Bag fucked around with this message at 17:25 on Sep 7, 2011

# ¿ Sep 7, 2011 17:08

Soup in a Bag: Dec 4, 2009

Are you calling include inside a method definition? I don't think you can do that. It should work at the top level or as part of a Module/Class definition though.

But you don't have to use include. For example, if your TestModule contains a class called TestClass, you could use either:

code:

require 'lib/test_module'
obj = TestModule::TestClass.new

or:

code:

require 'lib/test_module'
include TestModule
obj = TestClass.new

# ¿ Dec 22, 2011 17:31

Soup in a Bag: Dec 4, 2009

It's been a while since I've played with Shoes, but everything has show/hide/toggle methods for visibility and a remove method. Slots also have a clear method to remove their contents. The manual covers all that and more.

# ¿ Feb 4, 2012 11:12

Soup in a Bag: Dec 4, 2009

SquadronROE posted:

I'm learning Ruby right now, going through the Koans and I'm trying to create a method for one of the exercises. Right now, though, I'm stuck on trying to match up a set of numbers to an array.

Bottom line: Does .include? work if you pass an array to it? Will it then look inside a given array to see if the things are in there?

Nope. It will look for the object it's passed (in this case the entire array) and that's it.

Ruby code:

> [1, 1, 1, 1].include?([1, 1, 1])
=> false

> [[1, 1, 1], 1].include?([1, 1, 1])
=> true

The online Ruby docs are pretty handy for these sorts of questions.

# ¿ Mar 15, 2013 22:58

Soup in a Bag: Dec 4, 2009

If you want to read the entire stream in and then use it as if it were a file, check out StringIO. It responds to #rewind and all the other File/IO-ish methods.

# ¿ Nov 9, 2013 01:44

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# ¿ Apr 27, 2024 08:53

Soup in a Bag: Dec 4, 2009

Peristalsis, ssh has NumberOfPasswordPrompts as a config option (see man ssh_config). I don't know if Net::SSH gives access to those. On the command line it'd be

code:

$ ssh -o "NumberOfPasswordPrompts 1" user@host

# ¿ May 29, 2015 23:05

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