1 files changed, 28 insertions, 0 deletions
diff --git a/json.lisp b/json.lisp
index cb94985..5f570d5 100644
--- a/json.lisp
+++ b/json.lisp
@@ -20,3 +20,31 @@
                                (fail "Malformed exponent part."))
                        nothing)))
       (list 'number base fraction exponent))))
+
+(defparameter string-parser
+  (comp ((start (unit (lambda (x) (char= x #\"))))
+         (chars (zero-or-more (either (comp ((slash (unit (lambda (x) (char= x #\\))))
+                                             (escaped (unit))
+                                             (codepoints (if (and escaped (char= escaped #\u))
+                                                           (comp ((cp0 (unit #'digit-char-p))
+                                                                  (cp1 (unit #'digit-char-p))
+                                                                  (cp2 (unit #'digit-char-p))
+                                                                  (cp3 (unit #'digit-char-p)))
+                                                             (let ((str (make-string 4)))
+                                                               (setf (char str 0) cp0)
+                                                               (setf (char str 1) cp1)
+                                                               (setf (char str 2) cp2)
+                                                               (setf (char str 3) cp3)
+                                                               str))
+                                                           nothing)))
+                                        (case escaped
+                                          (#\n
+                                           #\Newline)
+                                          (#\t
+                                           #\Tab)
+                                          (#\u
+                                           codepoints)
+                                          (t escaped)))
+                                      (unit (lambda (x) (char/= x #\"))))))
+         (end (unit (lambda (x) (char= x #\")))))
+    (list 'string chars)))