Use destructuring assignments for named parameters (#180)

lib/runtime/dart/_internal.js

 dart_library.library('dart/_internal', null, /* Imports */[
   "dart/_runtime",
   'dart/core',
   'dart/collection'
 ], /* Lazy imports */[
   'dart/math',
   'dart/_interceptors',
   'dart/_js_primitives'
 ], function(exports, dart, core, collection, math, _interceptors, _js_primitives) {
   'use strict';
@@ skipping 65 matching lines @@
         let length = this.length;
         for (let i = 0; dart.notNull(i) < dart.notNull(length); i = dart.notNull(i) + 1) {
           if (dart.notNull(test(this.elementAt(i))))
             return true;
           if (length != this.length) {
             dart.throw(new core.ConcurrentModificationError(this));
           }
         }
         return false;
       }
-      firstWhere(test, opts) {
+      firstWhere(test, {orElse = null} = {}) {
         dart.as(test, dart.functionType(core.bool, [E]));
-        let orElse = opts && 'orElse' in opts ? opts.orElse : null;
         dart.as(orElse, dart.functionType(E, []));
         let length = this.length;
         for (let i = 0; dart.notNull(i) < dart.notNull(length); i = dart.notNull(i) + 1) {
           let element = this.elementAt(i);
           if (dart.notNull(test(element)))
             return element;
           if (length != this.length) {
             dart.throw(new core.ConcurrentModificationError(this));
           }
         }
         if (orElse != null)
           return orElse();
         dart.throw(IterableElementError.noElement());
       }
-      lastWhere(test, opts) {
+      lastWhere(test, {orElse = null} = {}) {
         dart.as(test, dart.functionType(core.bool, [E]));
-        let orElse = opts && 'orElse' in opts ? opts.orElse : null;
         dart.as(orElse, dart.functionType(E, []));
         let length = this.length;
         for (let i = dart.notNull(length) - 1; dart.notNull(i) >= 0; i = dart.notNull(i) - 1) {
           let element = this.elementAt(i);
           if (dart.notNull(test(element)))
             return element;
           if (length != this.length) {
             dart.throw(new core.ConcurrentModificationError(this));
           }
         }
@@ skipping 95 matching lines @@
         dart.as(test, dart.functionType(core.bool, [E]));
         return super.skipWhile(test);
       }
       take(count) {
         return new (SubListIterable$(E))(this, 0, count);
       }
       takeWhile(test) {
         dart.as(test, dart.functionType(core.bool, [E]));
         return super.takeWhile(test);
       }
-      toList(opts) {
-        let growable = opts && 'growable' in opts ? opts.growable : true;
+      toList({growable = true} = {}) {
         let result = null;
         if (dart.notNull(growable)) {
           result = core.List$(E).new();
           result[dartx.length] = this.length;
         } else {
           result = core.List$(E).new(this.length);
         }
         for (let i = 0; dart.notNull(i) < dart.notNull(this.length); i = dart.notNull(i) + 1) {
           result[dartx.set](i, this.elementAt(i));
         }
@@ skipping 117 matching lines @@
         core.RangeError.checkNotNegative(count, "count");
         if (this[_endOrLength] == null) {
           return new (SubListIterable$(E))(this[_iterable], this[_start], dart.notNull(this[_start]) + dart.notNull(count));
         } else {
           let newEnd = dart.notNull(this[_start]) + dart.notNull(count);
           if (dart.notNull(this[_endOrLength]) < dart.notNull(newEnd))
             return this;
           return new (SubListIterable$(E))(this[_iterable], this[_start], newEnd);
         }
       }
-      toList(opts) {
-        let growable = opts && 'growable' in opts ? opts.growable : true;
+      toList({growable = true} = {}) {
         let start = this[_start];
         let end = this[_iterable][dartx.length];
         if (this[_endOrLength] != null && dart.notNull(this[_endOrLength]) < dart.notNull(end))
           end = this[_endOrLength];
         let length = dart.notNull(end) - dart.notNull(start);
         if (dart.notNull(length) < 0)
           length = 0;
         let result = dart.notNull(growable) ? (() => {
           let _ = core.List$(E).new();
           _[dartx.length] = length;
@@ skipping 593 matching lines @@
         return false;
       }
       every(test) {
         dart.as(test, dart.functionType(core.bool, [E]));
         return true;
       }
       any(test) {
         dart.as(test, dart.functionType(core.bool, [E]));
         return false;
       }
-      firstWhere(test, opts) {
+      firstWhere(test, {orElse = null} = {}) {
         dart.as(test, dart.functionType(core.bool, [E]));
-        let orElse = opts && 'orElse' in opts ? opts.orElse : null;
         dart.as(orElse, dart.functionType(E, []));
         if (orElse != null)
           return orElse();
         dart.throw(IterableElementError.noElement());
       }
-      lastWhere(test, opts) {
+      lastWhere(test, {orElse = null} = {}) {
         dart.as(test, dart.functionType(core.bool, [E]));
-        let orElse = opts && 'orElse' in opts ? opts.orElse : null;
         dart.as(orElse, dart.functionType(E, []));
         if (orElse != null)
           return orElse();
         dart.throw(IterableElementError.noElement());
       }
-      singleWhere(test, opts) {
+      singleWhere(test, {orElse = null} = {}) {
         dart.as(test, dart.functionType(core.bool, [E]));
-        let orElse = opts && 'orElse' in opts ? opts.orElse : null;
         dart.as(orElse, dart.functionType(E, []));
         if (orElse != null)
           return orElse();
         dart.throw(IterableElementError.noElement());
       }
       join(separator) {
         if (separator === void 0)
           separator = "";
         return "";
       }
@@ skipping 22 matching lines @@
         return this;
       }
       take(count) {
         core.RangeError.checkNotNegative(count, "count");
         return this;
       }
       takeWhile(test) {
         dart.as(test, dart.functionType(core.bool, [E]));
         return this;
       }
-      toList(opts) {
-        let growable = opts && 'growable' in opts ? opts.growable : true;
+      toList({growable = true} = {}) {
         return dart.notNull(growable) ? dart.list([], E) : core.List$(E).new(0);
       }
       toSet() {
         return core.Set$(E).new();
       }
     }
     EmptyIterable[dart.implements] = () => [EfficientLength];
     dart.setSignature(EmptyIterable, {
       constructors: () => ({EmptyIterable: [EmptyIterable$(E), []]}),
       methods: () => ({
@@ skipping 1400 matching lines @@
   exports.ReversedListIterable = ReversedListIterable;
   exports.UnmodifiableListError = UnmodifiableListError;
   exports.NonGrowableListError = NonGrowableListError;
   exports.makeListFixedLength = makeListFixedLength;
   exports.Lists = Lists;
   exports.printToConsole = printToConsole;
   exports.Sort = Sort;
   exports.Symbol = Symbol;
   exports.POWERS_OF_TEN = POWERS_OF_TEN;
 });