From 76e53604573b087c4b7da939c95b7d76dbfdb4db Mon Sep 17 00:00:00 2001
From: shhyou <shu-hung.you@eecs.northwestern.edu>
Date: Thu, 24 Oct 2024 21:08:06 -0500
Subject: [PATCH] Enable the `use-function-output-syntax` option for ISL and
 plus. Fixes #208.

The printer for ISL, ISL+ and ASL relies on use-named/undefined-handler
and named/undefined-handler to correctly print named lambdas.
In particular, use-named/undefined-handler checks whether the option
use-function-output-syntax is set.

If use-function-output-syntax is not enabled, then during module
instantiation, user-written functions like my-add1 would be printed differently.
This also affects the error message from the check-expects.

    #lang htdp/isl+
    (define (my-add1 n) (+ n 1))
    my-add1
    (check-expect my-add1 2)

Output:

    Welcome to DrRacket.
    (lambda (a1) ...)

    Ran 1 test.
    0 tests passed.

    check-expect ... error ... :: first argument of equality cannot
    be a function, given (lambda (a1) ...)

    > my-add1
    my-add1
---
 htdp-lib/htdp/bsl/runtime.rkt                | 10 ++++++++--
 htdp-lib/lang/htdp-langs.rkt                 |  2 ++
 htdp-lib/lang/private/teach-module-begin.rkt |  5 ++++-
 3 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/htdp-lib/htdp/bsl/runtime.rkt b/htdp-lib/htdp/bsl/runtime.rkt
index d31a86cb..3d548420 100644
--- a/htdp-lib/htdp/bsl/runtime.rkt
+++ b/htdp-lib/htdp/bsl/runtime.rkt
@@ -85,11 +85,17 @@
    (lambda (x)
      (and (sl-runtime-settings-use-function-output-syntax? settings)
           (procedure? x)
+          (and (object-name x)
+               (not (regexp-match? #px"[.][.][.].*[.]rkt:\\d+:\\d+"
+                                   (symbol->string (object-name x))))
+               (not (regexp-match? #px"/[^/]*[.]rkt:\\d+:\\d+"
+                                   (symbol->string (object-name x)))))
           (object-name x))))
+  ;; The ISL case -- sl-runtime-settings-output-function-instead-of-lambda? --
+  ;; is already covered by the current-print-convert-hook above.
   (named/undefined-handler
    (lambda (x)
-     (string->symbol
-      (format "function:~a" (object-name x)))))
+     (object-name x)))
 
   ; sharing done by print-convert
   (show-sharing (sl-runtime-settings-show-sharing? settings))
diff --git a/htdp-lib/lang/htdp-langs.rkt b/htdp-lib/lang/htdp-langs.rkt
index aec0c43a..6e2fcbac 100644
--- a/htdp-lib/lang/htdp-langs.rkt
+++ b/htdp-lib/lang/htdp-langs.rkt
@@ -1022,6 +1022,7 @@
          (language-numbers '(-500 -500 5))
          (sharing-printing #t)
          (abbreviate-cons-as-list #t)
+         (use-function-output-syntax? #t)
          (allow-sharing? #t)
          (reader-module '(lib "htdp-advanced-reader.ss" "lang"))
          (debugger:supported #t)
@@ -1051,6 +1052,7 @@
          (language-numbers '(-500 -500 4))
          (sharing-printing #f)
          (abbreviate-cons-as-list #t)
+         (use-function-output-syntax? #t)
          (allow-sharing? #f)
          (reader-module '(lib "htdp-intermediate-lambda-reader.ss" "lang"))
          (stepper:supported #t)
diff --git a/htdp-lib/lang/private/teach-module-begin.rkt b/htdp-lib/lang/private/teach-module-begin.rkt
index 4f6fc4ac..ab2866f3 100644
--- a/htdp-lib/lang/private/teach-module-begin.rkt
+++ b/htdp-lib/lang/private/teach-module-begin.rkt
@@ -184,11 +184,14 @@
                         output-function-instead-of-lambda))
      (mk-module-begin '(abbreviate-cons-as-list
                         read-accept-quasiquote
+                        use-function-output-syntax
                         output-function-instead-of-lambda))
      (mk-module-begin '(abbreviate-cons-as-list
-                        read-accept-quasiquote))
+                        read-accept-quasiquote
+                        use-function-output-syntax))
      (mk-module-begin '(abbreviate-cons-as-list
                         read-accept-quasiquote
+                        use-function-output-syntax
                         show-sharing))
 
      ;; module-continue