Split a character string based on change of character: Difference between revisions

=={{header|Tcl}}==

This is most concise with regular expressions. Note well the two steps: it could be achieved in one very clever regexp, but being that clever is usually a bad idea (for both readability and performance, in this case).

<lang Tcl>set string "gHHH5YY++///\\"

regsub -all {(.)\1*} $string {\0, } string

regsub {, $} $string {} string

puts $string</lang>