add some handy builtin character classes as split separators (#84)

tablizer.1

@@ -133,7 +133,7 @@
 .\" ========================================================================
 .\"
 .IX Title "TABLIZER 1"
-.TH TABLIZER 1 "2025-10-01" "1" "User Commands"
+.TH TABLIZER 1 "2025-10-09" "1" "User Commands"
 .\" For nroff, turn off justification.  Always turn off hyphenation; it makes
 .\" way too many mistakes in technical documents.
 .if n .ad l
@@ -152,7 +152,7 @@ tablizer \- Manipulate tabular output of other programs
 \&      \-n, \-\-numbering                    Enable header numbering
 \&      \-N, \-\-no\-color                     Disable pattern highlighting
 \&      \-H, \-\-no\-headers                   Disable headers display
-\&      \-s, \-\-separator <string>           Custom field separator
+\&      \-s, \-\-separator <string>           Custom field separator (maybe char, string or :class:)
 \&      \-k, \-\-sort\-by <int|name>           Sort by column (default: 1)
 \&      \-z, \-\-fuzzy                        Use fuzzy search [experimental]
 \&      \-F, \-\-filter <field[!]=reg>        Filter given field with regex, can be used multiple times
@@ -293,6 +293,62 @@ Sorts timestamps.
 .PP
 Finally the  \fB\-d\fR option  enables debugging  output which  is mostly
 useful for the developer.
+.SS "\s-1SEPARATOR\s0"
+.IX Subsection "SEPARATOR"
+The option \fB\-s\fR can be a single character, in which case the \s-1CSV\s0
+parser will be invoked. You can also specify a string as
+separator. The string will be interpreted as literal string unless it
+is a valid go regular expression. For example:
+.PP
+.Vb 1
+\&    \-s \*(Aq\et{2,}\e\*(Aq
+.Ve
+.PP
+is being used as a regexp and will match two or more consecutive tabs.
+.PP
+.Vb 1
+\&    \-s \*(Aqfoo\*(Aq
+.Ve
+.PP
+on the other hand is no regular expression and will be used literally.
+.PP
+To make live easier, there are a couple of predefined regular
+expressions, which you can specify as classes:
+.Sp
+.RS 4
+* 		:tab:
+.Sp
+Matches a tab and eats spaces around it.
+.Sp
+*		:spaces:
+.Sp
+Matches 2 or more spaces.
+.Sp
+*		:pipe:
+.Sp
+Matches a pipe character and eats spaces around it.
+.Sp
+*		:default:
+.Sp
+Matches 2 or more spaces or tab. This is the default separator if none
+is specified.
+.Sp
+*		:nonword:
+.Sp
+Matches a non-word character.
+.Sp
+*		:nondigit:
+.Sp
+Matches a non-digit character.
+.Sp
+*		:special:
+.Sp
+Matches one or more special chars like brackets, dollar sign, slashes etc.
+.Sp
+*		:nonprint:
+.Sp
+Matches one or more non-printable characters.
+.RE
 .SS "\s-1PATTERNS AND FILTERING\s0"
 .IX Subsection "PATTERNS AND FILTERING"
 You can reduce  the rows being displayed by using  one or more regular