08-27-周三_17-09-29

node_modules/d3/src/arrays/nest.js

@@ -0,0 +1,97 @@
+import "map";
+
+d3.nest = function() {
+  var nest = {},
+      keys = [],
+      sortKeys = [],
+      sortValues,
+      rollup;
+
+  function map(mapType, array, depth) {
+    if (depth >= keys.length) return rollup
+        ? rollup.call(nest, array) : (sortValues
+        ? array.sort(sortValues)
+        : array);
+
+    var i = -1,
+        n = array.length,
+        key = keys[depth++],
+        keyValue,
+        object,
+        setter,
+        valuesByKey = new d3_Map,
+        values;
+
+    while (++i < n) {
+      if (values = valuesByKey.get(keyValue = key(object = array[i]))) {
+        values.push(object);
+      } else {
+        valuesByKey.set(keyValue, [object]);
+      }
+    }
+
+    if (mapType) {
+      object = mapType();
+      setter = function(keyValue, values) {
+        object.set(keyValue, map(mapType, values, depth));
+      };
+    } else {
+      object = {};
+      setter = function(keyValue, values) {
+        object[keyValue] = map(mapType, values, depth);
+      };
+    }
+
+    valuesByKey.forEach(setter);
+    return object;
+  }
+
+  function entries(map, depth) {
+    if (depth >= keys.length) return map;
+
+    var array = [],
+        sortKey = sortKeys[depth++];
+
+    map.forEach(function(key, keyMap) {
+      array.push({key: key, values: entries(keyMap, depth)});
+    });
+
+    return sortKey
+        ? array.sort(function(a, b) { return sortKey(a.key, b.key); })
+        : array;
+  }
+
+  nest.map = function(array, mapType) {
+    return map(mapType, array, 0);
+  };
+
+  nest.entries = function(array) {
+    return entries(map(d3.map, array, 0), 0);
+  };
+
+  nest.key = function(d) {
+    keys.push(d);
+    return nest;
+  };
+
+  // Specifies the order for the most-recently specified key.
+  // Note: only applies to entries. Map keys are unordered!
+  nest.sortKeys = function(order) {
+    sortKeys[keys.length - 1] = order;
+    return nest;
+  };
+
+  // Specifies the order for leaf values.
+  // Applies to both maps and entries array.
+  nest.sortValues = function(order) {
+    sortValues = order;
+    return nest;
+  };
+
+  nest.rollup = function(f) {
+    rollup = f;
+    return nest;
+  };
+
+  return nest;
+};