Method: String#succ

Defined in:

lib/source/ruby.rb

#succ ⇒ Object

call-seq:

str.next -> string
str.succ -> string

Returns the successor to str. The successor is calculated by incrementing characters starting from the rightmost alphanumeric (or the rightmost character if there are no alphanumerics) in the string. Incrementing a digit always results in another digit, and incrementing a letter results in another letter of the same case.

If the increment generates a “carry,” the character to the left is also incremented. This process repeats until there is no carry, adding an additional character of the same type as the leftmost alphanumeric, if necessary.

'abcdef'.succ     #=> 'abcdeg'
'<<kit9>>'.succ   #=> '<<kit10>>'
'1999zzz'.succ    #=> '2000aaa'
'ZZZ9999'.succ    #=> 'AAAA0000'

# File 'lib/source/ruby.rb', line 6002

def succ
  `var v=this.__value__`
  `if(!/[a-zA-Z0-9]/.test(v)){return $q(v);}`
  `if(/^\\d+$/.test(v)){return $q(''+(+v+1))}`
  `for(var i=v.length-1,carry=i>=0,result='';i>=0;--i){var c=v[i],lc=/[a-z]/.test(c),uc=/[A-Z]/.test(c),n=/[0-9]/.test(c);if($T(carry)&&(lc||uc||n)){if(lc||uc){if(c=='z'||c=='Z'){result=(lc?'a':'A')+result;carry=i;}else{result=String.fromCharCode(c.charCodeAt()+1)+result;carry=false;};}else{if(c=='9'){result='0'+result;carry=i}else{result=''+(+c+1)+result;carry=false;};};}else{result=c+result;};}`
  `if($T(carry)){var c=v[carry],insert=/[a-z]/.test(c)?'a':(/[A-Z]/.test(c)?'A':'1');result=result.slice(0,carry)+insert+result.slice(carry,result.length);}`
  return `$q(result)`
end