[SOLVED] StringRegExpReplace()

[jchd]

As regex101.com says:

/(((?<=^|[^\\])(?:\\\\)+)|()(?<=^|[^\\]))[^\\]/
        1st Capturing group (((?<=^|[^\\])(?:\\\\)+)|()(?<=^|[^\\]))
            1st Alternative: ((?<=^|[^\\])(?:\\\\)+)
                2nd Capturing group ((?<=^|[^\\])(?:\\\\)+)
                    (?<=^|[^\\]) Positive Lookbehind - Assert that the regex below can be matched
                        1st Alternative: ^
                            ^ assert position at start of the string
                        2nd Alternative: [^\\]
                            [^\\] match a single character not present in the list below
                                \\ matches the character \ literally
                    (?:\\\\)+ Non-capturing group
                        Quantifier: + Between one and unlimited times, as many times as possible, giving back as needed [greedy]
                        \\ matches the character \ literally
                        \\ matches the character \ literally
            2nd Alternative: ()(?<=^|[^\\])
                3rd Capturing group ()
                    (null, matches any position)
                (?<=^|[^\\]) Positive Lookbehind - Assert that the regex below can be matched
                    1st Alternative: ^
                        ^ assert position at start of the string
                    2nd Alternative: [^\\]
                        [^\\] match a single character not present in the list below
                            \\ matches the character \ literally
        [^\\] match a single character not present in the list below
            \\ matches the character \ literally

I'd call it tricky at best

[mikell]

Bah...  it's a try to do it using only one SRER and no other functions 
But it's not much more tricky than nested SRER
The more robust way could be a workaround anyway

$sVar = "000\a\aa\\bbb\\\ccc\\\\ddd\\\\\eee\\\\\\fff\\\\\\\ggg"
;expected result:   ...\a\a.\\...\\\c..\\\\....\\\\\e..\\\\\\...\\\\\\\\g..

; nested SRER
$sOut = StringRegExpReplace(StringRegExpReplace($sVar, '(?<=^|[^\\])[^\\]', "."), '((?<=^|[^\\])(?:\\\\)+)[^\\]', "$1.")
Msgbox(0,"1", $sOut)

; workaround
$r = "#"  ; temporary replacement char
$tmp1 = StringReplace($sVar, '\\', $r&$r)
$tmp2 = StringRegExpReplace($tmp1, '(?<!\\)[^\\' & $r & ']', ".")
$sOut = StringReplace($tmp2, $r&$r, '\\')
Msgbox(0,"2", $sOut)