RJM Here, a simple proc is proposed that allows simple wiki-like formatting for text widgets. Intended use case: help/manual text in Tcl sources. The insert subcommand's ability to have multiple text|tag-pairs is not bad, but common wiki markup would be better. In typical manual or help pages, basic markup as headings, underline, bold and italic would be very helpful.
A difficulty is the fact that you cannot have tags for bold and italic. Here one is forced to create a tag for both options together in the tag configure subcommand. In my proposal, I used some Creole markup features, because of its intuitively logical appearance.
witext .t "This is //italic __underline italic__ **bold italic**//\n" witext .t "This is **bold __underline bold__ //italic bold//**, yeah\n" witext .t "== Heading ==\nNormal text //italic// Text, __underline__ and **bold** text.\n"
proc witext_tags t { $t tag config ** -font {Courier 9 bold} $t tag config // -font {Courier 9 italic} $t tag config //** -font {Courier 9 italic bold} $t tag config __ -underline 1 $t tag config == -font {Verdana 10 bold} } set recurlevel 0 proc witext {t str args} { set pattern {(==|__|//|\*\*)(.+?)(\1)} if {[regsub -all $pattern $str {\x1d\2\x1e\1\x1d} str] || !$::recurlevel} { foreach str [split [subst $str] \x1d] { lassign [split $str \x1e] s tag incr ::recurlevel if {![witext $t $s [join "$tag $args" ""]]} { if {[regexp {//\*\*|\*\*//} $tag$args]} { set $args "" set tag //** ;# treat italic and bold as one compound tag (necessary) } $t insert end $s [list $tag $args] } incr ::recurlevel -1 } return 1 } return 0 }
I'm not sure whether the algorithmical approach makese sense or not. It seems to be difficult to convert wiki markup to a string that can be used as a compound single string to a text insert subcommand argument. Instead I subdivided the input string in sections using an ascii control code. Hence, a foreach handles each section: those without markup and those with markup.
Another ascii control code is used as a split marker in the inner loop. Another approach should be possible, here. The recursive approach allows nesting of markup. The recurlevel serves as a flag to ensure that text without any markup is passed as well.
For my purpose (help text in tcl-code) this helper proc is fully sufficient. Bullet and numeric listing would be nice as a next step.