sandbox/rst2graph/sortDot.pl

   1 #!/usr/bin/perl -w
   2
   3 # Sort the statements of a dot file produced by `rst2gv` so the sequence of
   4 # lines is stable.
   5
   6 my @gather;
   7
   8 sub add($) {
   9   my( $ln ) = @_;
  10
  11   push(@gather, $ln);
  12 }
  13
  14 sub out(@) {
  15   my( @lns ) = @_;
  16
  17   print(@lns);
  18 }
  19
  20 sub flush(@) {
  21   my( @sfx ) = @_;
  22
  23   out(sort(@gather), @sfx);
  24   @gather = ( );
  25 }
  26
  27 while(defined($_ = <>)) {
  28   my $in;
  29   if($in = /\{\s*$/ .. /\}\s*$/) {
  30     if($in == 1)
  31       { out($_); }
  32     elsif($in =~ /E/)
  33       { flush($_); }
  34     elsif(/\{\s*$/)
  35       { die("Embedded graphs are not supported: $_"); }
  36     elsif(/\\$/)
  37       { die("Continuation lines are not supported: $_"); }
  38     elsif(/\/\*/ || /\/\// || /#/)
  39       { die("Comments are not supported: $_"); }
  40     elsif(/;\s*$/) { # A statement
  41       if(/^\s*(graph|node|edge)/) # An attribute statement
  42         { flush($_); }
  43       # Note: The order of nodes output by `pygraphviz` is random. This changes
  44       # the semantic of the graph but unfortunately can not be controlled.
  45       else
  46         { add($_); }
  47     }
  48     else
  49       { die("Unsupported line ending: $_"); }
  50   }
  51   else
  52     { out($_); }
  53 }