[Dave.Touretzky@B.GP.CS.CMU.EDU: pluralization: two proposals]

[Guy Steele <gls@Think.COM>]

To: common-lisp@sail.stanford.edu
Subject: pluralization:  two proposals
Date: Mon, 27 Feb 89 04:37:06 EST
 From: Dave.Touretzky@B.GP.CS.CMU.EDU

The ~P format directive and its : and @ variants provide only the suffixes
"s" and "ies".  What about nouns whose singular forms end in "s" or
"z"?  They use "es" to form their plural, e.g.

   bus     -->  buses
   glass   -->  glasses
   buzz    -->  buzzes

First, I propose that ~P and ~:P be modified to produce the "es" plural
form instead of "s" when given a numeric argument of -1.

Second, a more ambitious proposal: how about introducing a new conditional
directive to handle arbitrary singular/plural distinctions:

  ~:@[ singular ~; plural ~]

If the argument is EQL to 1, the first alternative is taken; otherwise the
second alternative is taken.  This lets you do neat things like:

  (format nil "There ~:@[is~;are~]~:* ~D~:* ~:@[wolf~;wolves~] here." 3)
    ==>  "There are 3 wolves here."

  (format nil "There ~:@[is~;are~]~:* ~D~:* ~:@[wolf~;wolves~] here." 1)
    ==>  "There is 1 wolf here."


  (format nil "Your tab comes to ~D~:* ~:@[wolfs'~;wolves'~] head~:P." -5)
    ==>  "Your tab comes to -5 wolves' heads."

  (format nil "Your tab comes to ~D~:* ~:@[wolf's~;wolves'~] head~:P." 1)
    ==>  "Your tab comes to 1 wolf's head."

Notes:

1) The example with -5 shows why special plural forms can't simply be
handled with an ordinary conditional by writing

  ~[plural~;singular~:;plural~]

2) The pluralization conditional is also useful for handling things like
possessive forms (wolf's vs. wolves') and the verb "be" (is vs. are).

-- Dave