regex - Remove everything else from the String using regular expression -

i have regular expression allowed in string.

    ^\pl*['#-]?\pl*\$ 

the requirements have changed , need drop else string. example 1 of these special characters ', #, , - allowed.

how can change regex drop else not fit ?

here list of expected values:

johno'connell  -> allowed. should is. johndias       -> allowed. should is. johnoconnell'  -> allowed. should is. johnoconnell#  -> allowed. should is. johnoconnell-  -> allowed. should is. johnoconnell-# -> should return johnoconnell- johnoconn34ell -> should return johnoconnell *johnoconnell  -> should return johnoconnell johnoconnell*  -> should return johnoconnell johnoconn$%ell -> should return johnoconnell 

thanks

if understand correctly, way:

// test data def tests = [ [ input:"johno'connell",   output:"johno'connell" ],               [ input:"johndias",        output:"johndias" ],               [ input:"johnoconnell'",   output:"johnoconnell'" ],               [ input:"johnoconnell#",   output:"johnoconnell#" ],               [ input:"johnoconnell-",   output:"johnoconnell-" ],               [ input:"johnoconnell-#",  output:"johnoconnell-" ],               [ input:"johnoconn34ell",  output:"johnoconnell" ],               [ input:"*johnoconnell",   output:"johnoconnell" ],               [ input:"johnoconnell*",   output:"johnoconnell" ],               [ input:"johnoconn\$%ell", output:"johnoconnell" ] ]  string normalize( string input ) {     int idx = 0     input.replaceall( /[^a-za-z'#\-]/, '' )  // remove disallowed chars          .replaceall( /['#\-]/ ) { match ->  // replace 2nd+ instance of special chars              idx++ == 0 ? match : ''          } }  tests.each {     assert normalize( it.input ) == it.output }