class String

After some time trying to write libraries that used facets or extensions and didn’t conflict with other libraries that used (for example) active_support, I give up. I’m going to copy the methods I need, rename them to something so bad there’ll never be a conflict, and see if that’s more painful.

Public Instance Methods

has_exact_prefix?(prefix) click to toggle source

What everyone calls starts_with?

# File lib/s4t-utils/ruby-extensions.rb, line 12
def has_exact_prefix?(prefix)
 index(prefix) == 0
end

indent_by(n) click to toggle source

Indents the string n spaces. Taken from extensions (extensions.rubyforge.org), except that this version doesn’t take a negative argument.

# File lib/s4t-utils/ruby-extensions.rb, line 62
def indent_by(n)
  n = n.to_int
  gsub(/^/, " "*n)
end

without_pretty_indentation(margin=nil) click to toggle source

Copied from the extensions library (extensions.rubyforge.org)

Trims a string:

removes one initial blank line
removes trailing spaces on each line
if margin is given, removes initial spaces up to and including the margin on each line, plus one space

This is designed specifically for working with inline documents. Here-documents are great, except they tend to go against the indentation of your code. This method allows a convenient way of using %{}-style documents. For instance:

USAGE = %{
  | usage: prog [-o dir] -h file...
  |   where
  |     -o dir         outputs to DIR
  |     -h             prints this message
}.without_pretty_indentation("|")

# USAGE == "usage: prog [-o dir] -h file...\n  where"...
# (note single space to right of margin is deleted)

Note carefully that if no margin string is given, then there is no clipping at the beginning of each line and your string will remain indented.

# File lib/s4t-utils/ruby-extensions.rb, line 42
def without_pretty_indentation(margin=nil)
  s = self.dup
  # Remove initial blank line.
  s.sub!(/\A[ \t]*\n/, "")
  # Get rid of the margin, if it's specified.
  unless margin.nil?
    margin_re = Regexp.escape(margin || "")
    margin_re = /^[ \t]*#{margin_re} ?/
    s.gsub!(margin_re, "")
  end
  # Remove trailing whitespace on each line
  s.gsub!(/[ \t]+$/, "")
  s
end