Implement highlight specific for Fortran.

def highlight_block(self, text):
        """Implement highlight specific for Fortran."""
        text = to_text_string(text)
        self.setFormat(0, len(text), self.formats["normal"])
        
        match = self.PROG.search(text)
        index = 0
        while match:
            for key, value in list(match.groupdict().items()):
                if value:
                    start, end = match.span(key)
                    index += end-start
                    self.setFormat(start, end-start, self.formats[key])
                    if value.lower() in ("subroutine", "module", "function"):
                        match1 = self.IDPROG.match(text, end)
                        if match1:
                            start1, end1 = match1.span(1)
                            self.setFormat(start1, end1-start1,
                                           self.formats["definition"])
                    
            match = self.PROG.search(text, match.end())
        
        self.highlight_spaces(text)