Merge pull request #41 from eraserhd/position_in_zipper

track position in zipper implementation.

Author: Yannick Scherer

src/rewrite_clj/node.clj

@@ -28,6 +28,7 @@
    child-sexprs
    concat-strings
    inner?
+   leader-length
    length
    printable-only?
    replace-children

src/rewrite_clj/node/fn.clj

@@ -78,6 +78,8 @@
     children)
   (replace-children [this children']
     (assoc this :children children'))
+  (leader-length [_]
+    2)
 
   Object
   (toString [this]

src/rewrite_clj/node/forms.clj

@@ -26,6 +26,8 @@
     children)
   (replace-children [this children']
     (assoc this :children children'))
+  (leader-length [_]
+    0)
 
   Object
   (toString [this]

src/rewrite_clj/node/meta.clj

@@ -25,6 +25,8 @@
   (replace-children [this children']
     (node/assert-sexpr-count children' 2)
     (assoc this :children children'))
+  (leader-length [_]
+    (count prefix))
 
   Object
   (toString [this]

src/rewrite_clj/node/protocols.clj

@@ -55,14 +55,18 @@
   (children [_]
     "Get child nodes.")
   (replace-children [_ children]
-    "Replace the node's children."))
+    "Replace the node's children.")
+  (leader-length [_]
+    "How many characters appear before children?"))
 
 (extend-protocol InnerNode
   Object
   (inner? [_] false)
   (children [_]
     (throw (UnsupportedOperationException.)))
   (replace-children [_ _]
+    (throw (UnsupportedOperationException.)))
+  (leader-length [_]
     (throw (UnsupportedOperationException.))))
 
 (defn child-sexprs
@@ -113,3 +117,39 @@
 (defn ^:no-doc assert-single-sexpr
   [nodes]
   (assert-sexpr-count nodes 1))
+
+(defn ^:no-doc extent
+  "A node's extent is how far it moves the \"cursor\".
+
+  Rows are simple - if we have x newlines in the string representation, we
+  will always move the \"cursor\" x rows.
+
+  Columns are strange.  If we have *any* newlines at all in the textual
+  representation of a node, following nodes' column positions are not
+  affected by our startting column position at all.  So the second number
+  in the pair we return is interpreted as a relative column adjustment
+  when the first number in the pair (rows) is zero, and as an absolute
+  column position when rows is non-zero."
+  [node]
+  (let [{:keys [row col next-row next-col]} (meta node)]
+    (if (and row col next-row next-col)
+      [(- next-row row)
+       (if (= row next-row row)
+         (- next-col col)
+         next-col)]
+      (let [s (string node)
+            rows (->> s (filter (partial = \newline)) count)
+            cols (if (zero? rows)
+                   (count s)
+                   (->> s
+                     reverse
+                     (take-while (complement (partial = \newline)))
+                     count
+                     inc))]
+        [rows cols]))))
+
+(defn ^:no-doc +extent
+  [[row col] [row-extent col-extent]]
+  [(+ row row-extent)
+   (cond-> col-extent (zero? row-extent) (+ col))])
+

src/rewrite_clj/node/quote.clj

@@ -20,6 +20,8 @@
   (replace-children [this children']
     (node/assert-single-sexpr children')
     (assoc this :children children'))
+  (leader-length [_]
+    (count prefix))
 
   Object
   (toString [this]

src/rewrite_clj/node/reader_macro.clj

@@ -31,6 +31,8 @@
     (when sexpr-count
       (node/assert-sexpr-count children' sexpr-count))
     (assoc this :children children'))
+  (leader-length [_]
+    (inc (count prefix)))
 
   Object
   (toString [this]
@@ -55,6 +57,8 @@
   (replace-children [this children']
     (node/assert-sexpr-count children' 2)
     (assoc this :children children'))
+  (leader-length [_]
+    1)
 
   Object
   (toString [this]
@@ -79,6 +83,8 @@
   (replace-children [this children']
     (node/assert-sexpr-count children' 1)
     (assoc this :children children'))
+  (leader-length [_]
+    1)
 
   Object
   (toString [this]

src/rewrite_clj/node/seq.clj

@@ -27,6 +27,8 @@
     children)
   (replace-children [this children']
     (assoc this :children children'))
+  (leader-length [_]
+    (dec wrap-length))
 
   Object
   (toString [this]

src/rewrite_clj/node/uneval.clj

@@ -20,6 +20,8 @@
   (replace-children [this children']
     (node/assert-single-sexpr children')
     (assoc this :children children'))
+  (leader-length [_]
+    2)
 
   Object
   (toString [this]

src/rewrite_clj/zip.clj

@@ -17,13 +17,13 @@
              [parser :as p]
              [potemkin :refer [import-vars]]
              [node :as node]]
-            [clojure.zip :as z]))
+            [rewrite-clj.zip.zip :as z]))
 
 ;; ## API Facade
 
 (import-vars
-  [clojure.zip
-   node root]
+  [rewrite-clj.zip.zip
+   node position root]
 
   [rewrite-clj.zip.base
    child-sexprs
@@ -92,17 +92,19 @@
                :arglists `(quote ~arglists)})]
     `(def ~sym ~base)))
 
-(defbase right* clojure.zip/right)
-(defbase left* clojure.zip/left)
-(defbase up* clojure.zip/up)
-(defbase down* clojure.zip/down)
-(defbase next* clojure.zip/next)
-(defbase prev* clojure.zip/prev)
-(defbase rightmost* clojure.zip/rightmost)
-(defbase leftmost* clojure.zip/leftmost)
-(defbase replace* clojure.zip/replace)
-(defbase edit* clojure.zip/edit)
-(defbase remove* clojure.zip/remove)
+(defbase right* rewrite-clj.zip.zip/right)
+(defbase left* rewrite-clj.zip.zip/left)
+(defbase up* rewrite-clj.zip.zip/up)
+(defbase down* rewrite-clj.zip.zip/down)
+(defbase next* rewrite-clj.zip.zip/next)
+(defbase prev* rewrite-clj.zip.zip/prev)
+(defbase rightmost* rewrite-clj.zip.zip/rightmost)
+(defbase leftmost* rewrite-clj.zip.zip/leftmost)
+(defbase replace* rewrite-clj.zip.zip/replace)
+(defbase edit* rewrite-clj.zip.zip/edit)
+(defbase remove* rewrite-clj.zip.zip/remove)
+(defbase insert-left* rewrite-clj.zip.zip/insert-left)
+(defbase insert-right* rewrite-clj.zip.zip/insert-right)
 
 ;; ## DEPRECATED