RAHHH

backend/frontend/node_modules/tcomb/lib/update.js

@@ -0,0 +1,165 @@
+var assert = require('./assert');
+var isObject = require('./isObject');
+var isFunction = require('./isFunction');
+var isArray = require('./isArray');
+var isNumber = require('./isNumber');
+var assign = require('./assign');
+
+function getShallowCopy(x) {
+  if (isObject(x)) {
+    if (x instanceof Date || x instanceof RegExp) {
+      return x;
+    }
+    return assign({}, x);
+  }
+  if (isArray(x)) {
+    return x.concat();
+  }
+  return x;
+}
+
+function isCommand(k) {
+  return update.commands.hasOwnProperty(k);
+}
+
+function getCommand(k) {
+  return update.commands[k];
+}
+
+function update(instance, patch) {
+
+  if (process.env.NODE_ENV !== 'production') {
+    assert(isObject(patch), function () { return 'Invalid argument patch ' + assert.stringify(patch) + ' supplied to function update(instance, patch): expected an object containing commands'; });
+  }
+
+  var value = instance;
+  var isChanged = false;
+  var newValue;
+  for (var k in patch) {
+    if (patch.hasOwnProperty(k)) {
+      if (isCommand(k)) {
+        newValue = getCommand(k)(patch[k], value);
+        if (newValue !== instance) {
+          isChanged = true;
+          value = newValue;
+        } else {
+          value = instance;
+        }
+      }
+      else {
+        if (value === instance) {
+          value = getShallowCopy(instance);
+        }
+        newValue = update(value[k], patch[k]);
+        isChanged = isChanged || ( newValue !== value[k] );
+        value[k] = newValue;
+      }
+    }
+  }
+  return isChanged ? value : instance;
+}
+
+// built-in commands
+
+function $apply(f, value) {
+  if (process.env.NODE_ENV !== 'production') {
+    assert(isFunction(f), 'Invalid argument f supplied to immutability helper { $apply: f } (expected a function)');
+  }
+  return f(value);
+}
+
+function $push(elements, arr) {
+  if (process.env.NODE_ENV !== 'production') {
+    assert(isArray(elements), 'Invalid argument elements supplied to immutability helper { $push: elements } (expected an array)');
+    assert(isArray(arr), 'Invalid value supplied to immutability helper $push (expected an array)');
+  }
+  if (elements.length > 0) {
+    return arr.concat(elements);
+  }
+  return arr;
+}
+
+function $remove(keys, obj) {
+  if (process.env.NODE_ENV !== 'production') {
+    assert(isArray(keys), 'Invalid argument keys supplied to immutability helper { $remove: keys } (expected an array)');
+    assert(isObject(obj), 'Invalid value supplied to immutability helper $remove (expected an object)');
+  }
+  if (keys.length > 0) {
+    obj = getShallowCopy(obj);
+    for (var i = 0, len = keys.length; i < len; i++ ) {
+      delete obj[keys[i]];
+    }
+  }
+  return obj;
+}
+
+function $set(value) {
+  return value;
+}
+
+function $splice(splices, arr) {
+  if (process.env.NODE_ENV !== 'production') {
+    assert(isArray(splices) && splices.every(isArray), 'Invalid argument splices supplied to immutability helper { $splice: splices } (expected an array of arrays)');
+    assert(isArray(arr), 'Invalid value supplied to immutability helper $splice (expected an array)');
+  }
+  if (splices.length > 0) {
+    arr = getShallowCopy(arr);
+    return splices.reduce(function (acc, splice) {
+      acc.splice.apply(acc, splice);
+      return acc;
+    }, arr);
+  }
+  return arr;
+}
+
+function $swap(config, arr) {
+  if (process.env.NODE_ENV !== 'production') {
+    assert(isObject(config), 'Invalid argument config supplied to immutability helper { $swap: config } (expected an object)');
+    assert(isNumber(config.from), 'Invalid argument config.from supplied to immutability helper { $swap: config } (expected a number)');
+    assert(isNumber(config.to), 'Invalid argument config.to supplied to immutability helper { $swap: config } (expected a number)');
+    assert(isArray(arr), 'Invalid value supplied to immutability helper $swap (expected an array)');
+  }
+  if (config.from !== config.to) {
+    arr = getShallowCopy(arr);
+    var element = arr[config.to];
+    arr[config.to] = arr[config.from];
+    arr[config.from] = element;
+  }
+  return arr;
+}
+
+function $unshift(elements, arr) {
+  if (process.env.NODE_ENV !== 'production') {
+    assert(isArray(elements), 'Invalid argument elements supplied to immutability helper {$unshift: elements} (expected an array)');
+    assert(isArray(arr), 'Invalid value supplied to immutability helper $unshift (expected an array)');
+  }
+  if (elements.length > 0) {
+    return elements.concat(arr);
+  }
+  return arr;
+}
+
+function $merge(whatToMerge, value) {
+  var isChanged = false;
+  var result = getShallowCopy(value);
+  for (var k in whatToMerge) {
+    if (whatToMerge.hasOwnProperty(k)) {
+      result[k] = whatToMerge[k];
+      isChanged = isChanged || ( result[k] !== value[k] );
+    }
+  }
+  return isChanged ? result : value;
+}
+
+update.commands = {
+  $apply: $apply,
+  $push: $push,
+  $remove: $remove,
+  $set: $set,
+  $splice: $splice,
+  $swap: $swap,
+  $unshift: $unshift,
+  $merge: $merge
+};
+
+module.exports = update;