Marco Antoniotti <firstname.lastname@example.org> wrote:
| Madhu <enom...@meer.net> wrote:
| > (Rob Warnock) <k5GdnQM7O_aa6grUnZ2dnUVZ_j2dn...@speakeasy.net> wrote:
| > | Then there was a whole thread in late 2007 on ARRAY-IOTA.
| > Which reminds me to ask: could you consider and releasing OPFR?
| Wow. I *am* getting old. What is a OPFR?
"OPFR" == "Outer-Parenthesis-Free REPL". It's a meme/pattern/library(?)
that I've been talking about & using since early 1995 [if not earlier!],
first in Scheme, then in Common Lisp. The idea is simplicity itself:
a command-line reader that wrap a set of parens around whatever the user
types and then passes that to EVAL [with some minor tweaks so the most
common cases "do the right thing"]. The "rationale" comment from the
current CL version [soon to be public]:
;;; OPFR provides a simple command-line read-eval-print loop (REPL) for
;;; programs written in Common Lisp where the primary user community
;;; is uncomfortable using normal Lisp symbolic expressions (sexps).
;;; The simplicity and utility of OPFR derives from the observation
;;; that most such people are actually surprisingly accepting of an
;;; sexp-based interface *provided* that they are not required
;;; to manually type the outer pair of parentheses, *even if* any
;;; sub-expressions are still in pure Lisp sexp form!! This effect
;;; is even stronger when the majority of the command functions in the
;;; using application are provided as functions or macros, which only
;;; seldom require the typing of sub-expressions.
;;; This short example compares the syntaxes. First, normal Common Lisp:
;;; > (+ 1 2)
;;; > (defvar x 34)
;;; > (defvar y 25)
;;; > (expt x y)
;;; > (expt x (- y 12))
;;; Now, exactly the same sequence of operations using OPFR syntax:
;;; opfr> + 1 2
;;; ==> 3
;;; opfr> defvar x 34
;;; ==> X
;;; opfr> defvar y 25
;;; ==> Y
;;; opfr> expt x y
;;; ==> 193630125104980427932766033374162714624
;;; opfr> expt x (- y 12)
;;; ==> 81138303245565435904
;;; Note: The average Lisp programmer will see no significant advantage to
;;; the OPFR syntax (and some disadvantages, such as the need to resolve
;;; the ambiguity of a naked symbol -- should OPFR print its value as
;;; a global variable or call it as a "command" function?), especially
;;; since sub-expressions must still be fully-parenthesized (as in the
;;; last example above). Nevertheless, experience with real users has
;;; shown that the acceptance of the OPFR syntax is *enormously* greater
;;; than the "pure" Lisp sexp. [Go figure... (*sigh*)]
Search for me & OPFR or me & HWTOOL and you'll see lots more examples, e.g.:
Subject: Re: Why is LISP syntax superior?
Subject: Re: sweet-expressions instead of s-expressions?
Subject: Re: MUSING: standard bodies vs benevolent dictators, popularity
Rob Warnock <email@example.com>
627 26th Avenue <URL:http://rpw3.org/>
San Mateo, CA 94403 (650)572-2607