Mon Nov 23 11:33:15 UTC 2009  pix@kepibu.org
  * :first-child and :nth-child(n) selectors
diff -rN -u old-Oh, Ducks!/notes new-Oh, Ducks!/notes
--- old-Oh, Ducks!/notes	2015-10-28 03:50:22.000000000 +0000
+++ new-Oh, Ducks!/notes	2015-10-28 03:50:23.000000000 +0000
@@ -5,10 +5,11 @@
  * [ ] selectors involving descendants
 ** write documentation
 ** improve selector support
-*** positional selectors
- * [ ] :nth-child
+*** positional selectors [2/12]
+ * [X] :nth-child(n)
+ * [ ] :nth-child(xn+y)
  * [ ] :nth-last-child
- * [ ] :first-child
+ * [X] :first-child
  * [ ] :last-child
  * [ ] :nth-of-type
  * [ ] :nth-last-of-type
@@ -17,7 +18,7 @@
  * [ ] :only-child
  * [ ] :only-of-type
  * [ ] :empty
-*** attribute selectors
+*** attribute selectors [0/7]
  * [ ] attribute-present  [att]
  * [ ] attribute-equal    [att=val]
  * [ ] attribute-member   [att~=val]
diff -rN -u old-Oh, Ducks!/selectors.lisp new-Oh, Ducks!/selectors.lisp
--- old-Oh, Ducks!/selectors.lisp	2015-10-28 03:50:22.000000000 +0000
+++ new-Oh, Ducks!/selectors.lisp	2015-10-28 03:50:23.000000000 +0000
@@ -33,6 +33,10 @@
 (defclass type-selector  (simple-selector) ())
 (defclass id-selector    (simple-selector) ())
 (defclass class-selector (simple-selector) ())
+(defclass nth-child-selector (simple-selector) ())
+
+(defmethod print-object ((selector universal-selector) stream)
+  (format stream "#<universal-selector>"))
 
 (defmethod initialize-instance :after ((template combinator) &key)
   (unless (slot-boundp template 'matcher)
@@ -44,13 +48,23 @@
     ;; combinators
     #+TODO (#T(regexp$ "[ ]*[~][ ]*" ()) (list (make-instance 'sibling-combinator    :matcher (parse-selector &rest))))
     #+TODO (#T(regexp$ "[ ]*[+][ ]*" ()) (list (make-instance 'adjacent-combinator   :matcher (parse-selector &rest))))
-    (#T(regexp$ "[ ]*[>][ ]*" ()) (list (make-instance 'child-combinator      :matcher (parse-selector &rest))))
-    (#T(regexp$ "[ ]+"        ()) (list (make-instance 'descendant-combinator :matcher (parse-selector &rest))))
-    ;; simple selector
-    (#T(regexp$ "[#](\\w+)"   (?id))    (cons (make-instance 'id-selector :arg id)       (parse-selector &rest)))
-    (#T(regexp$ "[\\.](\\w+)" (?class)) (cons (make-instance 'class-selector :arg class) (parse-selector &rest)))
-    (#T(regexp$ "(\\w+)"      (?type))  (cons (make-instance 'type-selector :arg type)   (parse-selector &rest)))
-    (#T(regexp$ "\\*"         ())       (cons (make-instance 'universal-selector) (parse-selector &rest)))))
+    (#T(regexp$ "[ ]*[>][ ]*" ())
+     (list (make-instance 'child-combinator      :matcher (parse-selector &rest))))
+    (#T(regexp$ "[ ]+"        ())
+     (list (make-instance 'descendant-combinator :matcher (parse-selector &rest))))
+    ;; simple selectors
+    (#T(regexp$ ":nth-child\\([ ]*([0-9]+)[ ]*\\)" (?n))
+     (cons (make-instance 'nth-child-selector :arg (parse-integer n)) (parse-selector &rest)))
+    (#T(regexp$ ":first-child" ())
+     (cons (make-instance 'nth-child-selector :arg 1) (parse-selector &rest)))
+    (#T(regexp$ "[#](\\w+)"    (?id))
+     (cons (make-instance 'id-selector :arg id)       (parse-selector &rest)))
+    (#T(regexp$ "[\\.](\\w+)"  (?class))
+     (cons (make-instance 'class-selector :arg class) (parse-selector &rest)))
+    (#T(regexp$ "(\\w+)"       (?type))
+     (cons (make-instance 'type-selector :arg type)   (parse-selector &rest)))
+    (#T(regexp$ "\\*"          ())
+     (cons (make-instance 'universal-selector)        (parse-selector &rest)))))
 
 (defgeneric find-matching-elements (selector element)
   (:method (selector (element t))
@@ -70,6 +84,11 @@
 (defmethod element-matches-p (element (selector id-selector))
   (string= (element-id element) (selector-arg selector)))
 
+(defmethod element-matches-p (element (selector nth-child-selector))
+  (alexandria:when-let* ((parent (element-parent element))
+                         (pos (position element (element-children parent) :test #'eq)))
+    (= (selector-arg selector) (1+ pos))))
+
 (defmethod element-matches-p (element (selector class-selector))
   (member (selector-arg selector)
 	  (element-classes element)
diff -rN -u old-Oh, Ducks!/tests.lisp new-Oh, Ducks!/tests.lisp
--- old-Oh, Ducks!/tests.lisp	2015-10-28 03:50:22.000000000 +0000
+++ new-Oh, Ducks!/tests.lisp	2015-10-28 03:50:23.000000000 +0000
@@ -47,6 +47,12 @@
           "<div>I do <i>not</i> like cheese.</div><div><span>I like <i>cheese</i>.</span></div>")
   (values i span))
 
+(match (#T(html (:model dom)
+                ("div:first-child" . ?div)
+                ("i:nth-child(1)" . ?i))
+          "<div>I do <i>not</i> <i>like</i> cheese.</div><div><span>I like <i>cheese</i>.</span></div>")
+  (values div i))
+
 #+LATER
 (match (#t(html ("div::content" . #t(regexp+ "^f(o+)" (?o))))
         "<div>barbaz</div><div>fooooooobar</div>")