Export a JSON API that is compatible with SRFI-180

SRFI-180 represents JSON objects as alists from symbols to values,
while guile-json represents them as alists from strings to values.

Since alists are everywhere in the API, we need them to be as standard
as possible. So, we need them in SRFI-180 format.

4 files changed, 100 insertions, 27 deletions

diff --git a/po/fr.po b/po/fr.po
index b27cff8..f075033 100644
--- a/po/fr.po
+++ b/po/fr.po
@@ -126,62 +126,63 @@ msgstr "Utilisation : generate-random [NOMBRE D'OCTETS]\n"
 msgid "Usage: generate-key [NUMBER OF BITS | CURVE]\n"
 msgstr "Utilisation : generate-key [NOMBRE DE BITS | COURBE]\n"
 
-#: src/scm/webid-oidc/errors.scm:35
+#: src/scm/webid-oidc/errors.scm:45
 msgid "that’s how it is"
 msgstr "c’est comme ça"
 
-#: src/scm/webid-oidc/errors.scm:40
+#: src/scm/webid-oidc/errors.scm:50
 #, scheme-format
 msgid "the value ~s is not a base64 string (because ~a)"
 msgstr "la valeur ~s n’est pas une chaîne base64 (parce que ~a)"
 
-#: src/scm/webid-oidc/errors.scm:45
+#: src/scm/webid-oidc/errors.scm:53
+#, scheme-format
+msgid "the value ~s is not JSON (because ~a)"
+msgstr "la valeur ~s n’est pas du JSON (parce que ~a)"
+
+#: src/scm/webid-oidc/errors.scm:58
 msgid "that’s it"
 msgstr "c’est tout"
 
-#: src/scm/webid-oidc/errors.scm:49
+#: src/scm/webid-oidc/errors.scm:62
 #, scheme-format
 msgid "~a and ~a"
 msgstr "~a et ~a"
 
-#: src/scm/webid-oidc/errors.scm:52
+#: src/scm/webid-oidc/errors.scm:65
 #, scheme-format
 msgid "~a, ~a"
 msgstr "~a, ~a"
 
-#: src/scm/webid-oidc/errors.scm:56
+#: src/scm/webid-oidc/errors.scm:69
 msgid "there is an undefined variable"
 msgstr "il y a une variable non définie"
 
-#: src/scm/webid-oidc/errors.scm:58
+#: src/scm/webid-oidc/errors.scm:71
 #, scheme-format
 msgid "the origin is ~a"
 msgstr "l’origine est ~a"
 
-#: src/scm/webid-oidc/errors.scm:61
+#: src/scm/webid-oidc/errors.scm:74
 #, scheme-format
 msgid "a message is attached: ~a"
 msgstr "un message est attaché : ~a"
 
-#: src/scm/webid-oidc/errors.scm:64
+#: src/scm/webid-oidc/errors.scm:77
 #, scheme-format
 msgid "the values ~s are problematic"
 msgstr "les valeurs ~s sont problématiques"
 
-#: src/scm/webid-oidc/errors.scm:67
+#: src/scm/webid-oidc/errors.scm:80
 msgid "there is a kind and args"
 msgstr "il y a un type et des arguments"
 
-#: src/scm/webid-oidc/errors.scm:69
+#: src/scm/webid-oidc/errors.scm:82
 #, scheme-format
 msgid "Unhandled exception type ~a."
 msgstr "Type d’exception non pris en charge ~a."
 
 #, scheme-format
-#~ msgid "the value ~s is not JSON (because ~a)"
-#~ msgstr "la valeur ~s n’est pas du JSON (parce que ~a)"
-
-#, scheme-format
 #~ msgid "the value ~s is not Turtle (because ~a)"
 #~ msgstr "la valeur ~s n’est pas du Turtle (parce que ~a)"
 
diff --git a/po/webid-oidc.pot b/po/webid-oidc.pot
index ee78ff7..16dcfab 100644
--- a/po/webid-oidc.pot
+++ b/po/webid-oidc.pot
@@ -122,53 +122,58 @@ msgstr ""
 msgid "Usage: generate-key [NUMBER OF BITS | CURVE]\n"
 msgstr ""
 
-#: src/scm/webid-oidc/errors.scm:35
+#: src/scm/webid-oidc/errors.scm:45
 msgid "that’s how it is"
 msgstr ""
 
-#: src/scm/webid-oidc/errors.scm:40
+#: src/scm/webid-oidc/errors.scm:50
 #, scheme-format
 msgid "the value ~s is not a base64 string (because ~a)"
 msgstr ""
 
-#: src/scm/webid-oidc/errors.scm:45
+#: src/scm/webid-oidc/errors.scm:53
+#, scheme-format
+msgid "the value ~s is not JSON (because ~a)"
+msgstr ""
+
+#: src/scm/webid-oidc/errors.scm:58
 msgid "that’s it"
 msgstr ""
 
-#: src/scm/webid-oidc/errors.scm:49
+#: src/scm/webid-oidc/errors.scm:62
 #, scheme-format
 msgid "~a and ~a"
 msgstr ""
 
-#: src/scm/webid-oidc/errors.scm:52
+#: src/scm/webid-oidc/errors.scm:65
 #, scheme-format
 msgid "~a, ~a"
 msgstr ""
 
-#: src/scm/webid-oidc/errors.scm:56
+#: src/scm/webid-oidc/errors.scm:69
 msgid "there is an undefined variable"
 msgstr ""
 
-#: src/scm/webid-oidc/errors.scm:58
+#: src/scm/webid-oidc/errors.scm:71
 #, scheme-format
 msgid "the origin is ~a"
 msgstr ""
 
-#: src/scm/webid-oidc/errors.scm:61
+#: src/scm/webid-oidc/errors.scm:74
 #, scheme-format
 msgid "a message is attached: ~a"
 msgstr ""
 
-#: src/scm/webid-oidc/errors.scm:64
+#: src/scm/webid-oidc/errors.scm:77
 #, scheme-format
 msgid "the values ~s are problematic"
 msgstr ""
 
-#: src/scm/webid-oidc/errors.scm:67
+#: src/scm/webid-oidc/errors.scm:80
 msgid "there is a kind and args"
 msgstr ""
 
-#: src/scm/webid-oidc/errors.scm:69
+#: src/scm/webid-oidc/errors.scm:82
 #, scheme-format
 msgid "Unhandled exception type ~a."
 msgstr ""
diff --git a/src/scm/webid-oidc/errors.scm b/src/scm/webid-oidc/errors.scm
index 98859c9..9d08ed5 100644
--- a/src/scm/webid-oidc/errors.scm
+++ b/src/scm/webid-oidc/errors.scm
@@ -24,6 +24,16 @@
   (raise-exception
    ((record-constructor &not-base64) value cause)))
 
+(define-public &not-json
+  (make-exception-type
+   'not-json
+   &external-error
+   '(value cause)))
+
+(define-public (raise-not-json value cause)
+  (raise-exception
+   ((record-constructor &not-json) value cause)))
+
 (define*-public (error->str err #:key (max-depth #f))
   (if (record? err)
       (let* ((type (record-type-descriptor err))
@@ -39,6 +49,9 @@
           ((&not-base64)
            (format #f (G_ "the value ~s is not a base64 string (because ~a)")
                    (get 'value) (recurse (get 'cause))))
+          ((not-json)
+           (format #f (G_ "the value ~s is not JSON (because ~a)")
+                   (get 'value) (recurse (get 'cause))))
           ((&compound-exception)
            (let ((components (get 'components)))
              (if (null? components)
diff --git a/src/scm/webid-oidc/stubs.scm b/src/scm/webid-oidc/stubs.scm
index 5858986..0ef3fb5 100644
--- a/src/scm/webid-oidc/stubs.scm
+++ b/src/scm/webid-oidc/stubs.scm
@@ -1,6 +1,7 @@
 (define-module (webid-oidc stubs)
   #:use-module (webid-oidc config)
-  #:use-module (webid-oidc errors))
+  #:use-module (webid-oidc errors)
+  #:use-module (json))
 
 (load-extension
  (format #f "~a/libwebidoidc" libdir)
@@ -19,3 +20,56 @@
  random
  random-init!
  generate-key)
+
+;; json reader from guile-json will not behave consistently with
+;; SRFI-180 with objects: keys will be mapped to strings, not
+;; symbols. So we fix alist keys to be symbols.
+(define-public (fix-alists data)
+  (define (fix-an-alist rest alist)
+    (if (null? alist)
+        (reverse rest)
+        (let ((k/v (car alist))
+              (tail (cdr alist)))
+          (let ((key (car k/v))
+                (value (cdr k/v)))
+            (fix-an-alist
+             (acons (string->symbol key)
+                    (fix-alists value)
+                    rest)
+             tail)))))
+  (define (fix-a-vector vec)
+    (list->vector
+     (map fix-alists
+          (vector->list vec))))
+  (cond
+   ((list? data)
+    (fix-an-alist '() data))
+   ((vector? data)
+    (fix-a-vector data))
+   (else data)))
+
+(define (fixed:json-string->scm str)
+  (with-exception-handler
+      (lambda (err)
+        (raise-not-json str err))
+    (lambda ()
+      (fix-alists (json-string->scm str)))))
+
+(export (fixed:json-string->scm . json-string->scm))
+
+(define (fixed:json->scm port)
+  (with-exception-handler
+      (lambda (err)
+        (raise-not-json "(input)" err))
+    (lambda ()
+      (fix-alists (json->scm port)))))
+
+(export (fixed:json->scm . json->scm))
+
+(define fixed:scm->json-string scm->json-string)
+
+(export (fixed:scm->json-string . scm->json-string))
+
+(define fixed:scm->json scm->json)
+
+(export (fixed:scm->json . scm->json))