[m-dev.] State variable syntax - last call for opinions

[Ralph Becket]

If you have an opinion, please let me know which of these alternatives
for the state variable syntax you prefer ASAP:

(1 - the status quo)
	!+X refers to the "current" notional value of state variable X,
	!-X refers to the "next" notional value of state variable X.

	Inspiration: Prolog convention for labelling argument modes.

(2 - Fergus' suggestion, in receipt of broad support)
	!=X refers to the "current" notional value of state variable X,
	!+X refers to the "next" notional value of state variable X.

	Intuition: the `=' is indicative of keeping the state variable
	"number" the same (if one were to use variable numbering
	instead); the `+' is indicative of incrementing the state
	variable "number".

(3)
	!<X refers to the "current" notional value of state variable X,
	!>X refers to the "next" notional value of state variable X.

	Intuition: `<' is reminiscent of Unix shell "read" redirection;
	           `>' is reminiscent of Unix shell "write" redirection.

(Reminder: the parser will translate an argument !X into two arguments
!+X, !-X - or whatever symbols get the vote.)

Cheers,

Ralph
--------------------------------------------------------------------------
mercury-developers mailing list
Post messages to:       mercury-developers at cs.mu.oz.au
Administrative Queries: owner-mercury-developers at cs.mu.oz.au
Subscriptions:          mercury-developers-request at cs.mu.oz.au
--------------------------------------------------------------------------