linesToSets

linesToSets lines: returns list of ordered line sets

obj inscope fill proc linesToSets lines {
  if {$lines ne {}} then {
    set lineSet [[lindex $lines 0] chainedList]
    lappend rest
    foreach line $lines {
      if {$line ni $lineSet} then {
        lappend rest $line
      }
    }
    list $lineSet {*}[linesToSets $rest]
  }
}