Using RegExReplace() to match characters but not to replace/remove all matched characters

[BeetleAHK2]

Hi. I'm wanting a very simple result but am tearing my hair out trying to figger out how to use RegExReplace() to do it. I am still using AHK (not AHK_L) but I don't think that makes a difference with RegExReplace(). I have no code-writing knowledge (except for BATch -- which is why I love AHK so much). So, here's my Haystack (quotes only used for this Forum post):
"REPLACED MB & LCD BACK COVER,DMI, UPDATED BIOS."

What I want to do is use RegExReplace() to add a space after the commas to give me this result:
"REPLACED MB & LCD BACK COVER, DMI, UPDATED BIOS."

Pretty simple result, right? Well, nothing I've tried has worked:

Code: Select all

Newclip = REPLACED MB & LCD BACK COVER,DMI, UPDATED BIOS.

Newclip := RegExReplace(Newclip, ",[^,\w]", ", ")
; The above does nothing.
Newclip := RegExReplace(Newclip, ",[^,\w]", ", \w")
; The above does nothing.
Newclip := RegExReplace(Newclip, ",[^,\w", ", \w")
; The above removes everything.
Newclip := RegExReplace(Newclip, ",\w", ", \w")
; The above gives "REPLACED MB & LCD BACK COVER, \wMI, UPDATED BIOS."
Newclip := RegExReplace(Newclip, ",\w", ", ")
; The above gives "REPLACED MB & LCD BACK COVER, MI, UPDATED BIOS."
Newclip := RegExReplace(Newclip, ",", ", ")
; The above gives "REPLACED MB & LCD BACK COVER, DMI,  UPDATED BIOS."

Basically, I want to match any comma that has a character (other than a space) directly following it and then replace JUST the comma with a comma and space (or add a space after the existing comma without replacing said comma).

Why oh WHY does this have to be so hard?!! Please help me learn RegEx!
Thanks in advance, Beetle.

[phaleth]

Code: Select all

Newclip = REPLACED MB & LCD BACK COVER,DMI, UPDATED BIOS.

Newclip := RegExReplace(Newclip, ",\s?", ", ")

MsgBox, % Newclip

[lexikos]

To answer the original question, there are two ways to match characters but not replace them:

1. A look-ahead (?=positive) or (?!negative) or look-behind (?<=positive) or (?<!negative) will verify that a pattern matches before or after the current position, without consuming any characters (i.e. the content matched by the assertion does not get replaced). For example, (?<=,)(?! ) or (?<=,)(?=[^,\w]) would insert the replacement text without removing any characters.
2. \K resets the start position, so previously matched characters are not replaced.