Indentured Stringitude
October 2, 2011
Indentured Stringitude
One of the great things about Ruby is the extensive collection of methods available to the core classes. Of these the String class reigns supreme with over 100 methods from which to make good use. Among these methods are those we all use almost every time a string is laid to editor, such as #strip, #+ and #«. Others are present that have more specific but important uses, such as #lines, #scan and #getbyte. There are even a few that can leave one scratching ones head a bit trying to fathom the usecase, such as #sum.
Yet, despite its wide address, there is a set of methods that have gone completely overlooked, which is really remarkable when you consider their purpose, the frequency of their utility and the code savings they provide when used. These are methods dealing with indentation.
It was many years ago when I first was introduced to these three methods by Gavin Sinclair: #tab, $tabto and #indent. Their interfaces are:
tab(n)
Aligns each line n spaces.
tabto(n)
Preserves relative tabbing in which the first non-empty line ends up
with n spaces before non-space.
indent(n, c=' ')
Indent left or right by n spaces.
So clearly useful, these were some of the first to make their way in to Ruby Facets, and they have proven invaluable to me in numerous projects ever since.
Sometime shortly there after, another related method also proved useful at times, String#margin. It is documented:
margin(n=0)
Provides a margin controlled string.
x = %Q{
|This
| is
| margin controlled!
}.margin
This method is useful largely because it prevents a horrible code smell. How often have you seen some jutting HERE doc that threw all that nicely indented Ruby code to the wall.
def help_text
<<-HERE
Usage: foo bar
-x some option
-y another option
HERE
end
This all too common eye blight was the inspiration for the creation of #margin. In fact, so confident were Peter and I in this approach to remove these ugly code-squids that we conceived a %-literal to support such a construct would be an unimpeachable addition to the language itself, allowing the even more elegant notation:
x = %L|Usage: foo bar
|-x some option
|-y another option
Such a syntax, being built into Ruby proper, would not suffer the computational overhead of the pure Ruby implementation, or the extraneous brackets.
In all my years of coding Ruby, it seems to me, these are the the clearest omissions that I have repeatedly found need. And so concluded that they really should be a part of Ruby proper. And as much as I owe Ruby’s String class for all the time saving methods it provides, in this case, as often as I’ve had copy and paste or add a dependency to ‘facets’ just to get these methods, I think the String class owes me one!
title : String Indenture author : trans categories : [string, ruby] date : 2011-10-02 layout : post