Elm.Native.Array = {};
Elm.Native.Array.make = function(elm) {
elm.Native = elm.Native || {};
elm.Native.Array = elm.Native.Array || {};
if (elm.Native.Array.values) return elm.Native.Array.values;
if ('values' in Elm.Native.Array)
return elm.Native.Array.values = Elm.Native.Array.values;
var List = Elm.Native.List.make(elm);
// A RRB-Tree has two distinct data types.
// Leaf -> "height" is always 0
// "table" is an array of elements
// Node -> "height" is always greater than 0
// "table" is an array of child nodes
// "lengths" is an array of accumulated lengths of the child nodes
// M is the maximal table size. 32 seems fast. E is the allowed increase
// of search steps when concatting to find an index. Lower values will
// decrease balancing, but will increase search steps.
var M = 32;
var E = 2;
// An empty array.
var empty = { ctor:"_Array", height:0, table:new Array() };
function get(i, array) {
if (i < 0 || i >= length(array)) {
throw new Error("Index " + i + " is out of range. Check the length of " +
"your array first or use getMaybe or getWithDefault.");
}
return unsafeGet(i, array);
}
function unsafeGet(i, array) {
for (var x = array.height; x > 0; x--) {
var slot = i >> (x * 5);
while (array.lengths[slot] <= i) {
slot++;
}
if (slot > 0) {
i -= array.lengths[slot - 1];
}
array = array.table[slot];
}
return array.table[i];
}
// Sets the value at the index i. Only the nodes leading to i will get
// copied and updated.
function set(i, item, array) {
if (i < 0 || length(array) <= i) {
return array;
}
return unsafeSet(i, item, array);
}
function unsafeSet(i, item, array) {
array = nodeCopy(array);
if (array.height == 0) {
array.table[i] = item;
} else {
var slot = getSlot(i, array);
if (slot > 0) {
i -= array.lengths[slot - 1];
}
array.table[slot] = unsafeSet(i, item, array.table[slot]);
}
return array;
}
function initialize(len, f) {
if (len == 0) { return empty; }
var h = Math.floor(Math.log(len)/Math.log(M));
return initialize_(f, h, 0, len);
}
function initialize_(f, h, from, to) {
if (h == 0) {
var table = new Array((to - from) % (M + 1));
for (var i = 0; i < table.length; i++) {
table[i] = f(from + i);
}
return { ctor:"_Array", height:0, table:table };
}
var step = Math.pow(M, h);
var table = new Array(Math.ceil((to - from) / step));
var lengths = new Array(table.length);
for (var i = 0; i < table.length; i++) {
table[i] = initialize_( f, h - 1, from + (i * step)
, Math.min(from + ((i + 1) * step), to));
lengths[i] = length(table[i]) + (i > 0 ? lengths[i-1] : 0);
}
return { ctor:"_Array", height:h, table:table, lengths:lengths };
}
function fromList(list) {
if (list == List.Nil) { return empty; }
// Allocate M sized blocks (table) and write list elements to it.
var table = new Array(M);
var nodes = new Array();
var i = 0;
while (list.ctor !== '[]') {
table[i] = list._0;
list = list._1;
i++;
// table is full, so we can push a leaf containing it into the
// next node.
if (i == M) {
fromListPush({ ctor:"_Array", height:0, table:table }
, nodes);
table = new Array(M);
i = 0;
}
}
// Maybe there is something left on the table.
if (i > 0) {
fromListPush({ ctor:"_Array", height:0, table:table.splice(0,i) }
, nodes);
}
// Go through all of the nodes and eventually push them into higher nodes.
for (var h = 0; h < nodes.length - 1; h++) {
if (nodes[h].table.length > 0) {
fromListPush(nodes[h], nodes);
}
}
var head = nodes[nodes.length - 1];
if (head.height > 0 && head.table.length == 1) {
return head.table[0];
} else {
return head;
}
}
// Push a node into a higher node as a child.
function fromListPush(toPush, nodes) {
var h = toPush.height;
// Maybe the node on this height does not exist.
if (nodes.length == h) {
nodes.push({ ctor:"_Array", height:h + 1
, table:new Array()
, lengths:new Array() });
}
nodes[h].table.push(toPush);
var len = length(toPush);
if (nodes[h].lengths.length > 0) {
len += nodes[h].lengths[nodes[h].lengths.length - 1];
}
nodes[h].lengths.push(len);
if (nodes[h].table.length == M) {
fromListPush(nodes[h], nodes);
nodes[h] = { ctor:"_Array", height:h + 1
, table:new Array()
, lengths:new Array() };
}
}
// Pushes an item via push_ to the bottom right of a tree.
function push(item, a) {
var pushed = push_(item, a);
if (pushed !== null) {
return pushed;
}
var newTree = create(item, a.height);
return siblise(a, newTree);
}
// Recursively tries to push an item to the bottom-right most
// tree possible. If there is no space left for the item,
// null will be returned.
function push_(item, a) {
// Handle resursion stop at leaf level.
if (a.height == 0) {
if (a.table.length < M) {
var newA = { ctor:"_Array", height:0, table:a.table.slice() };
newA.table.push(item);
return newA;
} else {
return null;
}
}
// Recursively push
var pushed = push_(item, botRight(a));
// There was space in the bottom right tree, so the slot will
// be updated.
if (pushed != null) {
var newA = nodeCopy(a);
newA.table[newA.table.length - 1] = pushed;
newA.lengths[newA.lengths.length - 1]++;
return newA
}
// When there was no space left, check if there is space left
// for a new slot with a tree which contains only the item
// at the bottom.
if (a.table.length < M) {
var newSlot = create(item, a.height - 1);
var newA = nodeCopy(a);
newA.table.push(newSlot);
newA.lengths.push(newA.lengths[newA.lengths.length - 1] + length(newSlot));
return newA
} else {
return null;
}
}
// Converts an array into a list of elements.
function toList(a) {
return toList_(List.Nil, a);
}
function toList_(list, a) {
for (var i = a.table.length - 1; i >= 0; i--) {
list = a.height == 0 ? List.Cons(a.table[i], list) : toList_(list, a.table[i]);
}
return list;
}
// Maps a function over the elements of an array.
function map(f, a) {
var newA = { ctor:"_Array", height:a.height, table:new Array(a.table) };
if (a.height > 0) { newA.lengths = a.lengths; }
for (var i = 0; i < a.table.length; i++) {
newA.table[i] = a.height == 0 ? f(a.table[i]) : map(f, a.table[i]);
}
return newA;
}
// Maps a function over the elements with their index as first argument.
function indexedMap(f, a) {
return indexedMap_(f, a, 0);
}
function indexedMap_(f, a, from) {
var newA = { ctor:"_Array", height:a.height, table:new Array(a.table) };
if (a.height > 0) { newA.lengths = a.lengths; }
for (var i = 0; i < a.table.length; i++) {
newA.table[i] = a.height == 0 ? A2(f, from + i, a.table[i])
: indexedMap_( f, a.table[i]
, i == 0 ? 0 : a.lengths[i - 1]);
}
return newA;
}
function foldl(f, b, a) {
if (a.height == 0) {
for (var i = 0; i < a.table.length; i++) {
b = A2(f, a.table[i], b);
}
} else {
for (var i = 0; i < a.table.length; i++) {
b = foldl(f, b, a.table[i]);
}
}
return b;
}
function foldr(f, b, a) {
if (a.height == 0) {
for (var i = a.table.length; i--; ) {
b = A2(f, a.table[i], b);
}
} else {
for (var i = a.table.length; i--; ) {
b = foldl(f, b, a.table[i]);
}
}
return b;
}
// TODO: currently, it slices the right, then the left. This can be
// optimized.
function slice(from, to, a) {
if (from < 0) { from += length(a); }
if (to < 0) { to += length(a); }
return sliceLeft(from, sliceRight(to, a));
}
function sliceRight(to, a) {
if (to == length(a)) {
return a;
}
// Handle leaf level.
if (a.height == 0) {
var newA = { ctor:"_Array", height:0 };
newA.table = a.table.slice(0, to);
return newA;
}
// Slice the right recursively.
var right = getSlot(to, a);
var sliced = sliceRight(to - (right > 0 ? a.lengths[right - 1] : 0), a.table[right]);
// Maybe the a node is not even needed, as sliced contains the whole slice.
if (right == 0) {
return sliced;
}
// Create new node.
var newA = { ctor:"_Array", height:a.height
, table:a.table.slice(0, right)
, lengths:a.lengths.slice(0, right) };
if (sliced.table.length > 0) {
newA.table[right] = sliced;
newA.lengths[right] = length(sliced) + (right > 0 ? newA.lengths[right - 1] : 0);
}
return newA;
}
function sliceLeft(from, a) {
if (from == 0) {
return a;
}
// Handle leaf level.
if (a.height == 0) {
var newA = { ctor:"_Array", height:0 };
newA.table = a.table.slice(from, a.table.length + 1);
return newA;
}
// Slice the left recursively.
var left = getSlot(from, a);
var sliced = sliceLeft(from - (left > 0 ? a.lengths[left - 1] : 0), a.table[left]);
// Maybe the a node is not even needed, as sliced contains the whole slice.
if (left == a.table.length - 1) {
return sliced;
}
// Create new node.
var newA = { ctor:"_Array", height:a.height
, table:a.table.slice(left, a.table.length + 1)
, lengths:new Array(a.table.length - left) };
newA.table[0] = sliced;
var len = 0;
for (var i = 0; i < newA.table.length; i++) {
len += length(newA.table[i]);
newA.lengths[i] = len;
}
return newA;
}
// Appends two trees.
function append(a,b) {
if (a.table.length === 0) {
return b;
}
if (b.table.length === 0) {
return a;
}
var c = append_(a, b);
// Check if both nodes can be crunshed together.
if (c[0].table.length + c[1].table.length <= M) {
if (c[0].table.length === 0) {
return c[1];
}
if (c[1].table.length === 0) {
return c[0];
}
// Adjust .table and .lengths
c[0].table = c[0].table.concat(c[1].table);
if (c[0].height > 0) {
var len = length(c[0]);
for (var i = 0; i < c[1].lengths.length; i++) {
c[1].lengths[i] += len;
}
c[0].lengths = c[0].lengths.concat(c[1].lengths);
}
return c[0];
}
if (c[0].height > 0) {
var toRemove = calcToRemove(a, b);
if (toRemove > E) {
c = shuffle(c[0], c[1], toRemove);
}
}
return siblise(c[0], c[1]);
}
// Returns an array of two nodes; right and left. One node _may_ be empty.
function append_(a, b) {
if (a.height === 0 && b.height === 0) {
return [a, b];
}
if (a.height !== 1 || b.height !== 1) {
if (a.height === b.height) {
a = nodeCopy(a);
b = nodeCopy(b);
var appended = append_(botRight(a), botLeft(b));
insertRight(a, appended[1]);
insertLeft(b, appended[0]);
} else if (a.height > b.height) {
a = nodeCopy(a);
var appended = append_(botRight(a), b);
insertRight(a, appended[0]);
b = parentise(appended[1], appended[1].height + 1);
} else {
b = nodeCopy(b);
var appended = append_(a, botLeft(b));
var left = appended[0].table.length === 0 ? 0 : 1;
var right = left === 0 ? 1 : 0;
insertLeft(b, appended[left]);
a = parentise(appended[right], appended[right].height + 1);
}
}
// Check if balancing is needed and return based on that.
if (a.table.length === 0 || b.table.length === 0) {
return [a,b];
}
var toRemove = calcToRemove(a, b);
if (toRemove <= E) {
return [a,b];
}
return shuffle(a, b, toRemove);
}
// Helperfunctions for append_. Replaces a child node at the side of the parent.
function insertRight(parent, node) {
var index = parent.table.length - 1;
parent.table[index] = node;
parent.lengths[index] = length(node)
parent.lengths[index] += index > 0 ? parent.lengths[index - 1] : 0;
}
function insertLeft(parent, node) {
if (node.table.length > 0) {
parent.table[0] = node;
parent.lengths[0] = length(node);
var len = length(parent.table[0]);
for (var i = 1; i < parent.lengths.length; i++) {
len += length(parent.table[i]);
parent.lengths[i] = len;
}
} else {
parent.table.shift();
for (var i = 1; i < parent.lengths.length; i++) {
parent.lengths[i] = parent.lengths[i] - parent.lengths[0];
}
parent.lengths.shift();
}
}
// Returns the extra search steps for E. Refer to the paper.
function calcToRemove(a, b) {
var subLengths = 0;
for (var i = 0; i < a.table.length; i++) {
subLengths += a.table[i].table.length;
}
for (var i = 0; i < b.table.length; i++) {
subLengths += b.table[i].table.length;
}
var toRemove = a.table.length + b.table.length
return toRemove - (Math.floor((subLengths - 1) / M) + 1);
}
// get2, set2 and saveSlot are helpers for accessing elements over two arrays.
function get2(a, b, index) {
return index < a.length ? a[index] : b[index - a.length];
}
function set2(a, b, index, value) {
if (index < a.length) {
a[index] = value;
} else {
b[index - a.length] = value;
}
}
function saveSlot(a, b, index, slot) {
set2(a.table, b.table, index, slot);
var l = (index == 0 || index == a.lengths.length) ?
0 : get2(a.lengths, a.lengths, index - 1);
set2(a.lengths, b.lengths, index, l + length(slot));
}
// Creates a node or leaf with a given length at their arrays for perfomance.
// Is only used by shuffle.
function createNode(h, length) {
if (length < 0) { length = 0; }
var a = { ctor:"_Array", height:h, table:new Array(length) };
if (h > 0) {
a.lengths = new Array(length);
}
return a;
}
// Returns an array of two balanced nodes.
function shuffle(a, b, toRemove) {
var newA = createNode(a.height, Math.min(M, a.table.length + b.table.length - toRemove));
var newB = createNode(a.height, newA.table.length - (a.table.length + b.table.length - toRemove));
// Skip the slots with size M. More precise: copy the slot references
// to the new node
var read = 0;
while (get2(a.table, b.table, read).table.length % M == 0) {
set2(newA.table, newB.table, read, get2(a.table, b.table, read));
set2(newA.lengths, newB.lengths, read, get2(a.lengths, b.lengths, read));
read++;
}
// Pulling items from left to right, caching in a slot before writing
// it into the new nodes.
var write = read;
var slot = new createNode(a.height - 1, 0);
var from = 0;
// If the current slot is still containing data, then there will be at
// least one more write, so we do not break this loop yet.
while (read - write - (slot.table.length > 0 ? 1 : 0) < toRemove) {
// Find out the max possible items for copying.
var source = get2(a.table, b.table, read);
var to = Math.min(M - slot.table.length, source.table.length)
// Copy and adjust size table.
slot.table = slot.table.concat(source.table.slice(from, to));
if (slot.height > 0) {
var len = slot.lengths.length;
for (var i = len; i < len + to - from; i++) {
slot.lengths[i] = length(slot.table[i]);
slot.lengths[i] += (i > 0 ? slot.lengths[i - 1] : 0);
}
}
from += to;
// Only proceed to next slots[i] if the current one was
// fully copied.
if (source.table.length <= to) {
read++; from = 0;
}
// Only create a new slot if the current one is filled up.
if (slot.table.length == M) {
saveSlot(newA, newB, write, slot);
slot = createNode(a.height - 1,0);
write++;
}
}
// Cleanup after the loop. Copy the last slot into the new nodes.
if (slot.table.length > 0) {
saveSlot(newA, newB, write, slot);
write++;
}
// Shift the untouched slots to the left
while (read < a.table.length + b.table.length ) {
saveSlot(newA, newB, write, get2(a.table, b.table, read));
read++; write++;
}
return [newA, newB];
}
// Navigation functions
function botRight(a) { return a.table[a.table.length - 1]; }
function botLeft(a) { return a.table[0]; }
// Copies a node for updating. Note that you should not use this if
// only updating only one of "table" or "lengths" for performance reasons.
function nodeCopy(a) {
var newA = { ctor:"_Array", height:a.height
, table:a.table.slice() };
if (a.height > 0) { newA.lengths = a.lengths.slice(); }
return newA;
}
// Returns how many items are in the tree.
function length(array) {
if (array.height == 0) {
return array.table.length;
} else {
return array.lengths[array.lengths.length - 1];
}
}
// Calculates in which slot of "table" the item probably is, then
// find the exact slot via forward searching in "lengths". Returns the index.
function getSlot(i, a) {
var slot = i >> (5 * a.height);
while (a.lengths[slot] <= i) {
slot++;
}
return slot;
}
// Recursively creates a tree with a given height containing
// only the given item.
function create(item, h) {
if (h == 0) {
return { ctor:"_Array", height:0
, table:[item] };
} else {
return { ctor:"_Array", height:h
, table:[create(item, h - 1)]
, lengths:[1] };
}
}
// Recursively creates a tree that contains the given tree.
function parentise(tree, h) {
if (h == tree.height) {
return tree;
} else {
return { ctor:"_Array", height:h
, table:[parentise(tree, h - 1)]
, lengths:[length(tree)] };
}
}
// Emphasizes blood brotherhood beneath two trees.
function siblise(a, b) {
return { ctor:"_Array", height:a.height + 1
, table:[a, b]
, lengths:[length(a), length(a) + length(b)] };
}
function toJSArray(a) {
var jsArray = new Array(length(a));
toJSArray_(jsArray, 0, a);
return jsArray;
}
function toJSArray_(jsArray, i, a) {
for (var t = 0; t < a.table.length; t++) {
if (a.height == 0) {
jsArray[i + t] = a.table[t];
} else {
var inc = t == 0 ? 0 : a.lengths[t - 1];
toJSArray_(jsArray, i + inc, a.table[t]);
}
}
}
function fromJSArray(jsArray) {
if (jsArray.length == 0) { return empty; }
var h = Math.floor(Math.log(jsArray.length) / Math.log(M));
return fromJSArray_(jsArray, h, 0, jsArray.length);
}
function fromJSArray_(jsArray, h, from, to) {
if (h == 0) {
return { ctor:"_Array", height:0
, table:jsArray.slice(from, to) };
}
var step = Math.pow(M, h);
var table = new Array(Math.ceil((to - from) / step));
var lengths = new Array(table.length);
for (var i = 0; i < table.length; i++) {
table[i] = fromJSArray_( jsArray, h - 1, from + (i * step)
, Math.min(from + ((i + 1) * step), to));
lengths[i] = length(table[i]) + (i > 0 ? lengths[i-1] : 0);
}
return { ctor:"_Array", height:h, table:table, lengths:lengths };
}
Elm.Native.Array.values = {
empty:empty,
fromList:fromList,
toList:toList,
initialize:F2(initialize),
append:F2(append),
push:F2(push),
slice:F3(slice),
get:F2(get),
set:F3(set),
map:F2(map),
indexedMap:F2(indexedMap),
foldl:F3(foldl),
foldr:F3(foldr),
length:length,
toJSArray:toJSArray,
fromJSArray:fromJSArray
};
return elm.Native.Array.values = Elm.Native.Array.values;
}