Module: Hippo::Strings

Defined in:
lib/hippo/strings.rb

Constant Summary collapse

BAD_RAND_CHARS =

list of characters that should not be used

%w{ B 8 o O 0 i l I 1 }
RAND_CHARS =

characters that should be randomly chosen from

( ('A'..'Z').to_a + ('a'..'z').to_a + ('0'..'9').to_a ) - BAD_RAND_CHARS

Class Method Summary collapse

Class Method Details

.code_identifier(string, length: 10, padding: 'X') ⇒ String

Attempts to shorten a string while keeping it somewhat like it’s original self. Useful for suggesting a code for a given entity name. #### Examples:

Hippo::Strings.to_code_identifier('General Acme Corp')       #=> 'GENACMCORP'
Hippo::Strings.code_identifier('General I B', padding:false) #=> 'GENERALIB' *(no trailing X)*
Hippo::Strings.to_code_identifier('Top Cat', maxlen: 5 )     #=> 'TOCAT'

Parameters:

  • string (String) —

    the string to shorten.

  • length (Integer) (defaults to: 10) —

    how long the returned code should be

  • padding (String) (defaults to: 'X') —

    What to pad the code with if it is shorter than length. False indicates no padding should be performed

Returns:

  • (String) —

    a shortened version of the name with:

    • Upper cased

    • Spaces stripped

    • Made up of a proportional number of chars from each word



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# File 'lib/hippo/strings.rb', line 37

def self.code_identifier( string, length:10, padding: 'X' )
    stripped = string.gsub(/\W/, '').upcase
    if stripped.length < length
        return padding.present? ? stripped.ljust( length, padding ) : stripped
    end
    result = ''
    words = string.gsub(/[^\w\s-]/,'').split(/\s+|-|_/)
    0.upto(words.length + 1).each_with_index do | attempt_num |
        remainder = length
        result = ''
        string = words.each_with_index do | word, index |
            chars = ( remainder / (words.length-index) + attempt_num )
            result << word[0...chars]
            remainder = length - result.length
        end
        break if result.length >= length
    end
    result[0...length].upcase
end

.random(length = 12) ⇒ String

Generates a random string without using commonly confused numbers and letters. It’s intended for use in situations where the code will have to be read and re-entered later.

The characters in BAD_RAND_CHARS are avoided since they can be confused with one another:

Returns:

  • (String) —

    a random string <length> characters long.



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# File 'lib/hippo/strings.rb', line 19

def self.random( length = 12 )
    1.upto(length).each_with_object(''){|i,s| s << RAND_CHARS[ rand(RAND_CHARS.length) ] }
end