Module: SlimString

Extended by:
SlimString
Included in:
SlimString
Defined in:
lib/slim_string.rb,
lib/slim_string.rb

Overview

A module containing a method to slim down a UTF-8 String

It handles UTF8 characters, such as CJK (Zenkaku) spaces and offers many choices how to slim down a character string.

There are 3 ways to use the method #slim_string

(1) Simply call it in a full path

SlimString.slim_string("abc", trim: false)

(2) Include in your class/module (or top level), and you can

use it like: slim_string("abc", trim: false)

(3) Include it in String class like and you can used it like

an instance method.
  class String
    include SlimString
  end
  "abc".slim_string(trim: false)

Constant Summary collapse

DEF_SLIM_OPTIONS =

Default options of operations for #slim_string, which processes in this order if specified.

{
  :delete_newlines => false,  # Delete all new lines (\f\n\r\v) (useful for Japanese text, unless more than 1 alphabet word are split across 2 lines).
  :convert_spaces  => false,  # Convert any sort of spaces (including new lines) into an ASCII space.
  :convert_blanks  => true,   # Convert all blanks (=spaces except kind of new lines) into an ASCII space.
  :truncate_spaces => false,  # Truncate any consecutive spaces into one.
  :truncate_blanks => true,   # Truncate any consecutive blanks into (the last) one.
  :truncate_triple_newlines => false, # Truncate 3 or more consecutive newlines into 2.
  :delete_blanks   => false,  # Simply delete all blanks excluding new lines (n.b., "a top" and "atop" are regarded identical.
  :strip       => true,   # Ruby strip; strip spaces including new lines at the head and tail.
  :trim_blanks => false,  # strip blanks (but new lines) at the tail.
  :trim        => true,   # Trim the tail to strip any spaces including new lines at the tail.
}

Instance Method Summary collapse

Instance Method Details

#slim_string(str = nil, **opts) ⇒ String

Returns a slimmed down string

Parameters:

  • delete_newlines: (Boolean) —

    (Def: false) Delete all new lines (fnrv) (maybe useful for Japanese text, unless more than 1 alphabet word are split across 2 lines).

  • convert_spaces: (Boolean) —

    (Def: false) Convert any sort of spaces (including new lines) into an ASCII space.

  • convert_blanks: (Boolean) —

    (Def: true) Convert all blanks (=spaces except kind of new lines) into an ASCII space.

  • truncate_spaces: (Boolean) —

    (Def: false) Truncate any consecutive spaces into one.

  • truncate_blanks: (Boolean) —

    (Def: true) Truncate any consecutive blanks into (the last) one.

  • truncate_triple_newlines: (Boolean) —

    (Def: false) Truncate 3 or more consecutive newlines into 2.

  • delete_blanks: (Boolean) —

    (Def: false) Simply delete all blanks excluding new lines (n.b., “a top” and “atop” are regarded identical.

  • strip: (Boolean) —

    (Def: true) Ruby strip; strip spaces including new lines at the head and tail.

  • trim_blanks: (Boolean) —

    (Def: false) strip blanks (but new lines) at the tail.

  • trim: (Boolean) —

    (Def: true) Trim the tail to strip any spaces including new lines at the tail.

  • str (Hash) (defaults to: nil) —

    a customizable set of options

Options Hash (str):

  • Mandatory (String) —

    unless you use it as an instance method of String class.

Returns:

  • (String)

Raises:

  • (ArgumentError) —

    Unless you include this module from String class and use it as an instance method, the first argument is mandatory.



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# File 'lib/slim_string.rb', line 67

def slim_string(str=nil, **opts)
  begin
    ret = (str || self).dup
  rescue NoMethodError
    raise ArgumentError, 'first argument is mandatory and must be String-like.'
  end

  DEF_SLIM_OPTIONS.merge(opts).each_pair do |ek, tf|
    next if !tf
    case ek
    when :delete_newlines
         ret.tr! "\f\n\r\v", "" # ASCII Formfeed (FF), Linefeed (LF), Carriage Return (CR), Vertical Tab (VT)
    when :convert_spaces
         ret.gsub!(/[[:space:]]/,  ' ')
    when :convert_blanks
         ret.gsub!(/[[:blank:]]/,  ' ')
    when :truncate_spaces
         ret.gsub!(/([[:space:]])+/, '\1')
    when :truncate_blanks
         ret.gsub!(/([[:blank:]])+/, '\1')
    when :truncate_triple_newlines 
         ret.gsub!(/([\f\n\r\v]){3,}/, '\1\1')
    when :delete_blanks
         ret.gsub!(/[[:blank:]]+/, "")
    when :strip
         ret.strip!
    when :trim_blanks
         ret.gsub!(/[[:blank:]]+\z/, "")
    when :trim
         ret.gsub!(/([[:space:]])+\z/, "")
    else
      raise ArgumentError, 'Invalid optional argument: '+tf.inspect
    end
  end
  ret
end