silly regex question

[Joe Van Dyk]

Can someone help me make this code not suck?

require 'test/unit'

# EWWWWWWW
def process_string str
result =3D Hash.new
str.to_a.each do |line|
line.scan(/important ([a-zA-Z0-9]+): /) do |key|
result[key.first] =3D line
end
end
result
end

class TestThis < Test::Unit::TestCase
def example_string
<<-END
# comments
important key1: some value's here
important key2: some value's here
important key3: some value's here
important key4: some value's here

other stuff we don't care about
END
end

def test_process_string
result =3D process_string example_string
assert 4, result.size
assert result.has_key?("key1")
assert result.has_key?("key2")
assert result.has_key?("key3")
assert result.has_key?("key4")
end
end

 

[James Edward Gray II]

Can someone help me make this code not suck?

I guess it depends on what you mean by that...

require 'test/unit'

# EWWWWWWW
def process_string str
result = Hash.new
str.to_a.each do |line|
line.scan(/important ([a-zA-Z0-9]+): /) do |key|
result[key.first] = line
end
end
result
end

def process_string str
Hash[*str.scan(/^\s*(important ([a-zA-Z0-9]+): .+)
$/).flatten.reverse]
end

James Edward Gray II

 

[Joe Van Dyk]

Can someone help me make this code not suck?

I guess it depends on what you mean by that...

require 'test/unit'

# EWWWWWWW
def process_string str
result =3D Hash.new
str.to_a.each do |line|
line.scan(/important ([a-zA-Z0-9]+): /) do |key|
result[key.first] =3D line
end
end
result
end

def process_string str
Hash[*str.scan(/^\s*(important ([a-zA-Z0-9]+): .+)
$/).flatten.reverse]
end

IMO, my version's more readable. I'm going for readability here.

 

[James Edward Gray II]

IMO, my version's more readable. I'm going for readability here.

def process_string str
result = Hash.new
str.scan(/^\s*(important ([a-zA-Z0-9]+): .+?)\s*$/) do |line, key|
result[key] = line
end
result
end

# ... or ...

def process_string str
str.inject(Hash.new) do |result, line|
result[$1] = line if line =~ /^\s*important ([^:]+):/
result
end
end

James Edward Gray II

 

[Joe Van Dyk]

Another silly regex question.

I have a regex that's getting to be more than 100 chars long. How can
I split it up on multiple lines?

Joe

 

[Wilson Bilkovich]

Another silly regex question.

I have a regex that's getting to be more than 100 chars long. How can
I split it up on multiple lines?

You can put the 'x' option on the end of the regular expression.
From the Pickaxe:
ExtendedMode: Complex regular expressions can be difficult to read. The x o=
ption
allows you to insert spaces, newlines, and comments in the pattern to
make it more
readable.

e.g.
%r{some regex
with
multiple
lines
}x

 

[Dan Kohn]

Here's a rails example for validating email addresses.

validates_format_of :login, :with => /
^[-^!$#%&'*+\/=?`{|}~.\w]+
@[a-zA-Z0-9]([-a-zA-Z0-9]*[a-zA-Z0-9])*
(\.[a-zA-Z0-9]([-a-zA-Z0-9]*[a-zA-Z0-9])*)+$/x,
:message => "must be a valid email address",
n => :create

 

[Joe Van Dyk]

You can put the 'x' option on the end of the regular expression.
From the Pickaxe:
ExtendedMode: Complex regular expressions can be difficult to read. The x= option
allows you to insert spaces, newlines, and comments in the pattern to
make it more
readable.

e.g.
%r{some regex
with
multiple
lines
}x

ah, nice. Too bad vim doesn't highlight the comments.

 

[Chad Perrin]

def process_string str
str.inject(Hash.new) do |result, line|
result[$1] = line if line =~ /^\s*important ([^:]+):/
result
end
end

Not that I'm the one that has to read it, but . . .
I like this one for readability.

 

[Chad Perrin]

ah, nice. Too bad vim doesn't highlight the comments.

Have you tried setting this?:

:syntax on

 

[Devin Mullins]

Can someone help me make this code not suck?

require 'test/unit'

# EWWWWWWW
def process_string str
result = Hash.new
str.to_a.each do |line|
line.scan(/important ([a-zA-Z0-9]+): /) do |key|
result[key.first] = line
end
end
result
end

def process_string str
result = {}
str.each_line do |line|
important_stuff = line.split(/important\s+/,2)[1] or next
key, value = important_stuff.split ':'
result[key] = value
end
result
end
# More readable? I dunno... you be the judge. I might prefer it over:
# line, key, value = line.match /important\s+(\w+):\s*(.*)$/
# Though the latter is much more explicit.

 

[Jeffrey Moss]

I was just perfecting my email address validator, mine allows multiple
email addresses in the email_address field:

validates_format_of :email_address, :with =>
/^\s*(??:[^,@\s]+)@(??:[-a-z0-9]+\.)+[a-z]{2,}\s*(,\s*|\z)))+$/i,
:allow_nil => true

It doesn't do as careful of an inspection as yours, although I've seen
some validations that are far more detailed. It'd be nice to have some
people contribute their suggestions for the ultimate email address
validation regular expression.

I also have this handy method in my class:

def email_addresses
self.email_address.split(',').map{|a| a.lstrip.rstrip }
end

-Jeff

 

[Brian Caswell]

It doesn't do as careful of an inspection as yours, although I've seen
some validations that are far more detailed. It'd be nice to have some
people contribute their suggestions for the ultimate email address
validation regular expression.

It already exists. Go buy the first edition of Mastering Regular
Expressions. There 11 page regex that matches emails.

Brian

 

[Jeffrey Moss]

def email_addresses

Why do you lstrip and then rstrip? Won't a simple strip work for you?

YES! Nice to know! Hehe.

-Jeff