From a4f70ae598029e75d1ac12d01b63e98ca2140e9b Mon Sep 17 00:00:00 2001
From: Jay McCarthy <jay@racket-lang.org>
Date: Mon, 8 Aug 2011 11:55:49 -0600
Subject: [PATCH] Fixing PR12085

---
 collects/racklog/lang/configure-runtime.rkt | 20 ++++++++++++++++++++
 collects/racklog/lang/lang-info.rkt         | 10 ++++++++++
 collects/racklog/lang/reader.rkt            | 17 +++--------------
 collects/tests/racklog/pr/pr12085.rkt       | 15 +++++++++++++++
 4 files changed, 48 insertions(+), 14 deletions(-)
 create mode 100644 collects/racklog/lang/configure-runtime.rkt
 create mode 100644 collects/racklog/lang/lang-info.rkt
 create mode 100644 collects/tests/racklog/pr/pr12085.rkt

diff --git a/collects/racklog/lang/configure-runtime.rkt b/collects/racklog/lang/configure-runtime.rkt
new file mode 100644
index 0000000000..15e7164b51
--- /dev/null
+++ b/collects/racklog/lang/configure-runtime.rkt
@@ -0,0 +1,20 @@
+#lang racket/base
+
+(define (configure data)
+  ;; (printf "Configuring\n")
+  (current-read-interaction even-read))
+(provide configure)
+
+(require datalog/parse
+         racklog/lang/compiler)
+
+; XXX This is almost certainly wrong.
+(define (even-read src ip)
+  (begin0
+    (compile-statement
+     (parameterize ([current-source-name src])
+       (parse-statement ip)))
+    (current-read-interaction odd-read)))
+(define (odd-read src ip)
+  (current-read-interaction even-read)
+  eof)
diff --git a/collects/racklog/lang/lang-info.rkt b/collects/racklog/lang/lang-info.rkt
new file mode 100644
index 0000000000..ebde9a2927
--- /dev/null
+++ b/collects/racklog/lang/lang-info.rkt
@@ -0,0 +1,10 @@
+#lang racket/base
+
+(define (get-info data)
+  (λ (key default)
+    (case key
+      [(configure-runtime)
+       '(#(racklog/lang/configure-runtime configure #f))]
+      [else
+       default])))
+(provide get-info)
diff --git a/collects/racklog/lang/reader.rkt b/collects/racklog/lang/reader.rkt
index 738a7a8606..c1858dbec6 100644
--- a/collects/racklog/lang/reader.rkt
+++ b/collects/racklog/lang/reader.rkt
@@ -4,6 +4,8 @@
   #:read (lambda ([in (current-input-port)]) (this-read-syntax #f in))
   #:read-syntax this-read-syntax
   #:whole-body-readers? #t  
+  #:language-info
+  '#(racklog/lang/lang-info get-info #f)
   #:info (lambda (key defval default)
            ; XXX Should have different comment character key
            (case key
@@ -11,8 +13,6 @@
               (dynamic-require 'datalog/tool/submit 'repl-submit?)]
              [(color-lexer)
               (dynamic-require 'datalog/tool/syntax-color 'get-syntax-token)]
-             [(configure-runtime)
-              (λ () (current-read-interaction even-read))]
              [else (default key defval)]))
   (require datalog/parse
            racklog/lang/compiler)
@@ -21,15 +21,4 @@
     (list
      (compile-program
       (parameterize ([current-source-name src])
-        (parse-program in)))))
-  
-  ; XXX This is almost certainly wrong.
-  (define (even-read src ip)
-    (begin0
-      (compile-statement
-       (parameterize ([current-source-name src])
-         (parse-statement ip)))
-      (current-read-interaction odd-read)))
-  (define (odd-read src ip)
-    (current-read-interaction even-read)
-    eof))
+        (parse-program in))))))
diff --git a/collects/tests/racklog/pr/pr12085.rkt b/collects/tests/racklog/pr/pr12085.rkt
new file mode 100644
index 0000000000..28037022d4
--- /dev/null
+++ b/collects/tests/racklog/pr/pr12085.rkt
@@ -0,0 +1,15 @@
+#lang racklog
+
+% Run parent_child(P,C)? 
+
+mother_child(trude, sally).
+
+father_child(tom, sally).
+father_child(tom, erica).
+father_child(mike, tom).
+
+sibling(X, Y)      :- parent_child(Z, X), parent_child(Z, Y).
+
+parent_child(X, Y) :- father_child(X, Y).
+parent_child(X, Y) :- mother_child(X, Y).
+