# HG changeset patch
# User Steve Losh <steve@stevelosh.com>
# Date 1598743837 14400
# Node ID 2a95e54cdcac7cdea1dd9a54aae2cc27d83e9416
# Parent  af3ef34fe3baf1424854a7d7c9f392751added15
Remove opaque-json

It doesn't save that much over just parsing into vanilla `t`, and it makes the
code more complicated.

diff -r af3ef34fe3ba -r 2a95e54cdcac jarl.asd
--- a/jarl.asd	Sat Aug 29 19:22:07 2020 -0400
+++ b/jarl.asd	Sat Aug 29 19:30:37 2020 -0400
@@ -14,7 +14,7 @@
   :components ((:module "src" :serial t
                 :components ((:file "package")
                              (:file "basic")
-                             (:file "opaque")
+                             (:file "discard")
                              (:file "wrappers")
                              (:file "mop")))))
 
diff -r af3ef34fe3ba -r 2a95e54cdcac src/discard.lisp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/discard.lisp	Sat Aug 29 19:30:37 2020 -0400
@@ -0,0 +1,119 @@
+(in-package :jarl)
+
+;; Optimized reader for cases where you just want to make sure the JSON parses
+;; but don't want to allocate all the internal objects.
+
+
+(defun discard-hex-digit (input)
+  (let ((ch (r input)))
+    (if (eql :eof ch)
+      (e nil input "cannot parse \\u escape sequence, got ~S" :eof)
+      (or (digit-char-p ch 16)
+          (e nil input "cannot parse \\u escape sequence, ~S is not a hexadecimal digit" ch)))))
+
+(defun discard-escaped-character (input)
+  (let ((ch (r input)))
+    (case ch
+      ((#\" #\\ #\/ #\b #\f #\n #\r #\t) nil)
+      (#\u (loop :repeat 4 :do (discard-hex-digit input)))
+      (t (e nil input "bad escape sequence ~S ~S" #\\ ch))))
+  nil)
+
+(defun discard-literal (string input)
+  (loop :for next :across string
+        :for char = (r input)
+        :unless (eql next char)
+        :do (e nil input "expected ~S when parsing ~S but got ~S" next string char)))
+
+(defun discard-array (input)
+  (r input) ; [
+  (incf-depth input)
+  (skip-whitespace input)
+  (if (eql (p input) #\])
+    (progn (decf-depth input)
+           (r input))
+    (loop (discard-any input)
+          (skip-whitespace input)
+          (let ((ch (r input)))
+            (case ch
+              (#\] (decf-depth input) (return))
+              (#\, (skip-whitespace input))
+              (t (e nil input "expected ~S or ~S but got ~S." #\] #\, ch)))))))
+
+(defun discard-object (input)
+  (r input) ; {
+  (incf-depth input)
+  (skip-whitespace input)
+  (if (eql (p input) #\})
+    (progn (decf-depth input)
+           (r input))
+    (loop (discard-string input)
+          (parse-kv-separator nil input)
+          (discard-any input)
+          (skip-whitespace input)
+          (let ((ch (r input)))
+            (case ch
+              (#\} (decf-depth input) (return))
+              (#\, (skip-whitespace input))
+              (t (e nil input "expected ~S or ~S but got ~S" #\} #\, ch)))))))
+
+(defun discard-string (input)
+  (let ((ch (r input)))
+    (unless (eql ch #\")
+      (e nil input "expected opening ~S but got ~S" #\" ch)))
+  (loop :for ch = (r input)
+        :do (case ch
+              (:eof (e nil input "got ~S" :eof))
+              (#\\ (discard-escaped-character input))
+              (#\" (return))
+              (t (if (requires-escape-p ch)
+                   (e nil input "bad unescaped character ~S" ch)
+                   nil)))))
+
+(defun discard-int (input &optional (allow-leading-zero t))
+  (loop :for n :from 0
+        :for ch = (p input #\e)
+        :for digit = (digit-char-p ch)
+        :while digit
+        :do (progn (r input)
+                   (when (and (not allow-leading-zero)
+                              (zerop n) ; leading
+                              (zerop digit) ; zero
+                              (digit-char-p (p input #\e))) ; but not a bare zero
+                     (e nil input "bad leading zero")))
+        :finally (when (zerop n)
+                   (e nil input "expected an integer"))))
+
+(defun discard-exponent (input)
+  (when (member (p input) '(#\+ #\-))
+    (r input))
+  (discard-int input))
+
+(defun discard-number (input)
+  (when (eql #\- (p input))
+    (r input))
+  (discard-int input nil)
+  (when (eql #\. (p input))
+    (r input)
+    (discard-int input))
+  (when (member (p input) '(#\e #\E))
+    (r input)
+    (discard-exponent input)))
+
+(defun discard-any (input)
+  (case (p input)
+    (:eof (r input) (e 'discard-json input "got ~S" :eof))
+    (#\n (discard-literal "null" input))
+    (#\t (discard-literal "true" input))
+    (#\f (discard-literal "false" input))
+    (#\" (discard-string input))
+    (#\{ (discard-object input))
+    (#\[ (discard-array input))
+    ((#\- #\0 #\1 #\2 #\3 #\4 #\5 #\6 #\7 #\8 #\9) (discard-number input))
+    (t (e nil input "unexpected character ~S" (r input)))))
+
+
+(defmethod read% ((class (eql 'nil)) contained-class input)
+  (skip-whitespace input)
+  (discard-any input)
+  (values))
diff -r af3ef34fe3ba -r 2a95e54cdcac src/opaque.lisp
--- a/src/opaque.lisp	Sat Aug 29 19:22:07 2020 -0400
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,157 +0,0 @@
-(in-package :jarl)
-
-;; Optimized readers for cases where you just want to make sure the JSON parses
-;; and preserve it for later, but don't want to allocate all the internal
-;; objects.
-;;
-;; Parsing into opaque-json stores the JSON in a string so it can be emitted
-;; later, but doesn't bother allocating all the internal objects  It's similar
-;; to Golang's json.RawMessage.
-;;
-;; Parsing into nil parses the JSON to make sure it's well formed, but discards
-;; the characters entirely.
-;;
-;; TODO: Opaque JSON doesn't seem to save all that much over vanilla parsing.
-;; Investigate why, and whether we should bother with this at all.
-
-
-(defclass opaque-json ()
-  ((data :accessor data :initarg :data)))
-
-(defmethod print-object ((o opaque-json) s)
-  (print-unreadable-object (o s :type t)
-    (format s "~S" (if (> (length (data o)) 10)
-                     (concatenate 'string (subseq (data o) 0 10) "…")
-                     (data o)))))
-
-(defun w (input output) ; write through (and read)
-  (declare (type input input) (optimize (speed 3) (safety 1) (debug 1)))
-  (let ((ch (r input)))
-    (unless (or (null output) (eql :eof ch))
-      (write-char ch output))
-    ch))
-
-
-(defun opaque-hex-digit (input output)
-  (let ((ch (w input output)))
-    (if (eql :eof ch)
-      (e nil input "cannot parse \\u escape sequence, got ~S" :eof)
-      (or (digit-char-p ch 16)
-          (e nil input "cannot parse \\u escape sequence, ~S is not a hexadecimal digit" ch)))))
-
-(defun opaque-escaped-character (input output)
-  (let ((ch (w input output)))
-    (case ch
-      ((#\" #\\ #\/ #\b #\f #\n #\r #\t) nil)
-      (#\u (loop :repeat 4 :do (opaque-hex-digit input output)))
-      (t (e nil input "bad escape sequence ~S ~S" #\\ ch))))
-  nil)
-
-(defun opaque-literal (string input output)
-  (loop :for next :across string
-        :for char = (w input output)
-        :unless (eql next char)
-        :do (e nil input "expected ~S when parsing ~S but got ~S" next string char)))
-
-(defun opaque-array (input output)
-  (w input output) ; [
-  (incf-depth input)
-  (skip-whitespace input)
-  (if (eql (p input) #\])
-    (progn (decf-depth input)
-           (w input output))
-    (loop (opaque-any input output)
-          (skip-whitespace input)
-          (let ((ch (w input output)))
-            (case ch
-              (#\] (decf-depth input) (return))
-              (#\, (skip-whitespace input))
-              (t (e nil input "expected ~S or ~S but got ~S." #\] #\, ch)))))))
-
-(defun opaque-object (input output)
-  (w input output) ; {
-  (incf-depth input)
-  (skip-whitespace input)
-  (if (eql (p input) #\})
-    (progn (decf-depth input)
-           (w input output))
-    (loop (opaque-string input output)
-          (parse-kv-separator nil input)
-          (when output (write-char #\: output))
-          (opaque-any input output)
-          (skip-whitespace input)
-          (let ((ch (w input output)))
-            (case ch
-              (#\} (decf-depth input) (return))
-              (#\, (skip-whitespace input))
-              (t (e nil input "expected ~S or ~S but got ~S" #\} #\, ch)))))))
-
-(defun opaque-string (input output)
-  (let ((ch (w input output)))
-    (unless (eql ch #\")
-      (e nil input "expected opening ~S but got ~S" #\" ch)))
-  (loop :for ch = (w input output)
-        :do (case ch
-              (:eof (e nil input "got ~S" :eof))
-              (#\\ (opaque-escaped-character input output))
-              (#\" (return))
-              (t (if (requires-escape-p ch)
-                   (e nil input "bad unescaped character ~S" ch)
-                   nil)))))
-
-(defun opaque-int (input output &optional (allow-leading-zero t))
-  (loop :for n :from 0
-        :for ch = (p input #\e)
-        :for digit = (digit-char-p ch)
-        :while digit
-        :do (progn (w input output)
-                   (when (and (not allow-leading-zero)
-                              (zerop n) ; leading
-                              (zerop digit) ; zero
-                              (digit-char-p (p input #\e))) ; but not a bare zero
-                     (e nil input "bad leading zero")))
-        :finally (when (zerop n)
-                   (e nil input "expected an integer"))))
-
-(defun opaque-exponent (input output)
-  (when (member (p input) '(#\+ #\-))
-    (w input output))
-  (opaque-int input output))
-
-(defun opaque-number (input output)
-  (when (eql #\- (p input))
-    (w input output))
-  (opaque-int input output nil)
-  (when (eql #\. (p input))
-    (w input output)
-    (opaque-int input output))
-  (when (member (p input) '(#\e #\E))
-    (w input output)
-    (opaque-exponent input output)))
-
-(defun opaque-any (input output)
-  (case (p input)
-    (:eof (w input output) (e 'opaque-json input "got ~S" :eof))
-    (#\n (opaque-literal "null" input output))
-    (#\t (opaque-literal "true" input output))
-    (#\f (opaque-literal "false" input output))
-    (#\" (opaque-string input output))
-    (#\{ (opaque-object input output))
-    (#\[ (opaque-array input output))
-    ((#\- #\0 #\1 #\2 #\3 #\4 #\5 #\6 #\7 #\8 #\9) (opaque-number input output))
-    (t (e nil input "unexpected character ~S" (w input output)))))
-
-
-(defmethod read% ((class (eql 'opaque-json)) contained-class input)
-  (skip-whitespace input)
-  (make-instance 'opaque-json
-    :data (with-output-to-string (s)
-            (opaque-any input s))))
-
-(defmethod print% ((thing opaque-json) stream)
-  (write-string (data thing) stream))
-
-(defmethod read% ((class (eql 'nil)) contained-class input)
-  (skip-whitespace input)
-  (opaque-any input nil)
-  (values))
diff -r af3ef34fe3ba -r 2a95e54cdcac test/tests.lisp
--- a/test/tests.lisp	Sat Aug 29 19:22:07 2020 -0400
+++ b/test/tests.lisp	Sat Aug 29 19:30:37 2020 -0400
@@ -68,20 +68,15 @@
     (is (null (multiple-value-list (jarl:read nil s))))
     (signals end-of-file (jarl:read t s))))
 
-(defun check-opaques-one-object (object string)
-  (with-input-from-string (s string)
-    ;; Make sure we can read it as opaque JSON.
-    (let ((oj (jarl:read 'jarl::opaque-json s)))
-      ;; Roundtrip it through print and read again and make sure it doesn't get
-      ;; mangled.
-      (is (same object (jarl:read t (jarl:print oj nil)))))
-    (signals end-of-file (jarl:read t s))))
 
 (defun roundtrip-string (class-designator string)
   (jarl:print (jarl:read class-designator (json string)) nil))
 
+(defun roundtrip-object (class-designator object)
+  (jarl:read class-designator (jarl:print object nil)))
+
 (defun check-roundtrips (object)
-  (is (same object (jarl:read t (jarl:print object nil)))))
+  (is (same object (roundtrip-object t object))))
 
 (defun check-errors (line col string)
   (dolist (class '(t nil)) ; todo check discarding errors too
@@ -105,8 +100,6 @@
                   (check-reads-one-object ,object ,string)
                   ; Check that we can roundtrip the form reliably.
                   (check-roundtrips ,object)
-                  ; Check that we can parse it opaquely too.
-                  (check-opaques-one-object ,object ,string)
                   ; Check that we can discard it safely.
                   (check-discards-one-object ,string))))))