Regex to remove all special characters except periods

Question

I need help with creating a regex that removes all special characters, including commas, but not periods. What I have tried to do is escape all the characters, symbols and punctuation I do not want. It is not working as intended.

replace("[-\\[\\]^/,'*:.!><~@#\$%+=?|\"\\\\()]+".toRegex(), "")

I removed the period and tested that too. It did not work.

replace("[-\\[\\]^/,'*:!><~@#\$%+=?|\"\\\\()]+".toRegex(), "")

For example, lets take the String "if {cat.is} in a hat, then I eat green eggs and ham!".

I want the result

if {cat.is} in a hat then I eat green eggs and ham (comma and exclamation symbol removed)

Note: I want to keep brackets, although braces are OK to omit.

Anyone have a solution for this?

Answer 1

You can use

"""[\p{P}\p{S}&&[^.]]+""".toRegex()

The [\\p{P}\\p{S}&&[^.]]+ pattern matches one or more ( + ) punctuation proper ( \\p{P} ) or symbol ( \\p{S} ) chars other than dots ( &&[^.] , using character class subtraction).

See a Kotlin demo :

println("a-b)h.".replace("""[\p{P}\p{S}&&[^.]]+""".toRegex(), ""))
// => abh.