The ## syntax that some Smalltalks have (Smalltalk/X, for

example, which calls it a Dolphin extension) is related

to Common Lisp's

���� #.e���������� the result of evaluating e at *read* time,

���������������������� taken as a literal

���� #,e���������� the result of evaluating e at *load* time,

���������������������� taken as a literal.

This reminds us there are several times that a ## form

could be evaluated:

��- in the parser, when a method is parsed (before code

���� generation)

��- when code is generated

��- when code is generated AND whenever the image is

���� restored

��- when the value is first needed (I'd prefer this)

��- when the value is first needed in a thread (that

���� is, each thread that encounters it will evaluate

���� it just once, so each thread may see a different

���� value).

One continuing annoyance in Smalltalk is that I cannot

put a Fraction, a Date, a Time, or a DateAndTime in a

literal.�� It would be nice to have #1969-07-20 or #1/2

or #16:40:32 as literals and they contain no expressions

that could result in any confusion about when they are

evaluated and cannot be changed any more than a character

literal can.

Curly brace syntax {e1. ... en} is an expression form,

not a literal form.�� Similar forms for sets of several

kinds and dictionaries of several kinds are supported

in my Smalltalk, and they are indeed useful, but they

are especially useful because they are *not* literals

but create new values every time.