RCR: String#indent(n)

ruby-talk
1

Rubyists,

I think a fine companion for String#ljust, String#rjust and
String#center would be String#indent.

For example:

text = <<EOT
I must go down to the sea again
The lonely sea and sky
And all I want is a tall ship
And a star to steer me by
EOT

text.indent(4) == <<EOT # -> true
I must go down to the sea again
The lonely sea and sky
And all I want is a tall ship
And a star to steer me by
EOT

text.indent("-± ") == <<EOT # -> true
-± I must go down to the sea again
-± The lonely sea and sky
-± And all I want is a tall ship
-± And a star to steer me by
EOT

Note that the above code is demonstration only; I haven’t run it.

It would probably be better in hindsight to move #ljust et al into a
separate module (StringFormat, say) with which individual objects can
be extended at will. Then more and more utility methods can be added
without bloating String.

Gavin

2

Gavin Sinclair wrote:

Rubyists,

I think a fine companion for String#ljust, String#rjust and
String#center would be String#indent.

It’s pretty easy to just use gsub instead:

text.gsub(/^/, " "*4)

whereas ljust, rjust, and center would require a little more work to
emulate with gsub. Or do you have more functionality in mind?

Just for the heck of it, here are some bits I use from time to time.
They might fit in some kind of string formatting library.

class String

tabs left or right by n chars, using spaces

def tab n
if n >= 0
gsub(/^/, ’ ’ * n)
else
gsub(/^ {0,#{-n}}/, “”)
end
end

preserves relative tabbing

the first non-empty line ends up with n spaces before nonspace

def tabto n
if self =~ /^( *)\S/
tab(n - $1.length)
else
self
end
end

aligns each line

def taballto n
gsub(/^ */, ’ ’ * n)
end

end

3

Gavin Sinclair wrote:

Rubyists,

I think a fine companion for String#ljust, String#rjust and
String#center would be String#indent.

It’s pretty easy to just use gsub instead:

text.gsub(/^/, " "*4)

whereas ljust, rjust, and center would require a little more work to
emulate with gsub. Or do you have more functionality in mind?

No more, and I realised the gsub trick just after I hit send. Ease of
implementation alone doesn’t discount an idea, though :slight_smile:

Just for the heck of it, here are some bits I use from time to time.
They might fit in some kind of string formatting library.

Those are good. There’s a place on the Wiki for these. Is it
StandardClassExtensions? If you don’t add them, I will (when I get
around to it).

Cheers,
Gavin

···

On Tuesday, January 14, 2003, 3:16:03 PM, Joel wrote: