nomcompile3: Build a set of nomenclature files

An instance of this class represents the initial fields that are common to all standard forms line. Here is the class interface. The status code must be a one-character string; see Section 6.21, “STATUS_RE”.

# - - - - -   c l a s s   S t d H e a d

class StdHead(object):
    '''Represents the front part of a standard forms line.

      Exports:
        StdHead ( hier, scan ):
          [ (hier is a Hier instance) and
            (scan is a Scan instance) ->
              if the line in scan starts with a standard forms head ->
                if the rank code is in hier ->
                  scan  :=  scan advanced past the head
                  return a new StdHead instance representing the head
                else ->
                  scan  :=  scan not advanced past end of line
                  raise KeyError
              else ->
                scan  :=  scan advanced not past end of line
                Log()  +:=  error messages
                raise SyntaxError ]
        .rank:
          [ if the head had no rank code -> None
            else -> the rank as a Rank instance in hier ]
        .status:
          [ the status code as a string that matches STATUS_RE ]
    '''