xnomo3.py: Internal maintenance specification

This class is fairly similar to Section 10.4, “class Htmler: State machine for HTML markup”: it is a small state machine for converting double-quote characters to their paired form, and for interpreting underbar characters as italic-start and italic-end characters.

The narrative for this class will be minimal, as it uses the same mechanism as the Htmler class; only the markup characters are different.

# - - - - -   c l a s s   T e x e r

class Texer(object):
    '''State machine for TeX markup of English names.

      Exports:
        Texer():
          [ return a new Texer instance, not in quotes or italics ]
        .quotes:
          [ if self is between quotes -> True
            else -> False ]
        .italics:
          [ if self is between underbars -> True
            else -> False ]
        .convert(c):
          [ if c is a double-quote ->
              if self.quotes ->
                self.quotes  :=  False
                return TEX_RQ
              else ->
                self.quotes  :=  True
                return TEX_LQ
            else if c is an underbar ->
              if self.italics ->
                self.italics  :=  False
                return TEX_ITAL_END
              else ->
                self.italics  :=  False
                return TEX_ITAL_START
            else -> return c ]
    '''