5
Das Problem
ich auf einer JavaScript-Bibliothek arbeiten bin derzeit zu schaffen, und um die Menge von Fehlern zu reduzieren, dachte ich, dass meine Bibliothek statisch verwenden, Dart typing Mechanismus profitieren könnte. Erstens, weil meine lib weder mit HTML noch mit anderen JavaScript-Bibliotheken interoperierte, sondern nur reine JavaScript-Objektmanipulation. Ich habe jedoch keine Informationen im Internet gefunden, die zeigen, wie es möglich ist, eine JS-Bibliothek mit Dart zu erstellen. Also habe ich versucht zu tun, dass ich selbst, anfängliche dart-Datei erstellt:Mit dart einer JavaScript-Bibliothek
library Repo;
class Type {
final String name;
final TypeCategory category;
Type(String name, TypeCategory category) : name = name, category = category {
category.types[name] = this;
}
}
class TypeCategory {
final String name;
final Map<String, Type> types = new Map();
TypeCategory(this.name);
}
class Branch {
}
class Descriptor {
}
class TableDescriptor extends Descriptor {
TableDescriptor.ctor() {
}
}
class Repo {
Descriptor descriptor(String name) {
}
Branch branch(String name) {
}
void Merge() {
}
}
main() {
return Repo;
}
Zusammengestellt es JavaScript dart2js verwenden, um zu sehen, wie ich tue:
// Generated by dart2js, the Dart to JavaScript compiler version: 1.3.6.
// The code supports the following hooks:
// dartPrint(message):
// if this function is defined it is called instead of the Dart [print]
// method.
//
// dartMainRunner(main, args):
// if this function is defined, the Dart [main] method will not be invoked
// directly. Instead, a closure that will invoke [main], and its arguments
// [args] is passed to [dartMainRunner].
(function($) {
function dart(){ this.x = 0 }var A = new dart;
delete A.x;
var B = new dart;
delete B.x;
var C = new dart;
delete C.x;
var D = new dart;
delete D.x;
var E = new dart;
delete E.x;
var F = new dart;
delete F.x;
var G = new dart;
delete G.x;
var H = new dart;
delete H.x;
var J = new dart;
delete J.x;
var K = new dart;
delete K.x;
var L = new dart;
delete L.x;
var M = new dart;
delete M.x;
var N = new dart;
delete N.x;
var O = new dart;
delete O.x;
var P = new dart;
delete P.x;
var Q = new dart;
delete Q.x;
var R = new dart;
delete R.x;
var S = new dart;
delete S.x;
var T = new dart;
delete T.x;
var U = new dart;
delete U.x;
var V = new dart;
delete V.x;
var W = new dart;
delete W.x;
var X = new dart;
delete X.x;
var Y = new dart;
delete Y.x;
var Z = new dart;
delete Z.x;
function Isolate() {}
init();
$ = Isolate.$isolateProperties;
var $$ = {};
(function (reflectionData) {
"use strict";
function map(x){x={x:x};delete x.x;return x}
function processStatics(descriptor) {
for (var property in descriptor) {
if (!hasOwnProperty.call(descriptor, property)) continue;
if (property === "^") continue;
var element = descriptor[property];
var firstChar = property.substring(0, 1);
var previousProperty;
if (firstChar === "+") {
mangledGlobalNames[previousProperty] = property.substring(1);
var flag = descriptor[property];
if (flag > 0) descriptor[previousProperty].$reflectable = flag;
if (element && element.length) init.typeInformation[previousProperty] = element;
} else if (firstChar === "@") {
property = property.substring(1);
$[property]["@"] = element;
} else if (firstChar === "*") {
globalObject[previousProperty].$defaultValues = element;
var optionalMethods = descriptor.$methodsWithOptionalArguments;
if (!optionalMethods) {
descriptor.$methodsWithOptionalArguments = optionalMethods = {}
}
optionalMethods[property] = previousProperty;
} else if (typeof element === "function") {
globalObject[previousProperty = property] = element;
functions.push(property);
init.globalFunctions[property] = element;
} else if (element.constructor === Array) {
addStubs(globalObject, element, property, true, descriptor, functions);
} else {
previousProperty = property;
var newDesc = {};
var previousProp;
for (var prop in element) {
if (!hasOwnProperty.call(element, prop)) continue;
firstChar = prop.substring(0, 1);
if (prop === "static") {
processStatics(init.statics[property] = element[prop]);
} else if (firstChar === "+") {
mangledNames[previousProp] = prop.substring(1);
var flag = element[prop];
if (flag > 0) element[previousProp].$reflectable = flag;
} else if (firstChar === "@" && prop !== "@") {
newDesc[prop.substring(1)]["@"] = element[prop];
} else if (firstChar === "*") {
newDesc[previousProp].$defaultValues = element[prop];
var optionalMethods = newDesc.$methodsWithOptionalArguments;
if (!optionalMethods) {
newDesc.$methodsWithOptionalArguments = optionalMethods={}
}
optionalMethods[prop] = previousProp;
} else {
var elem = element[prop];
if (prop !== "^" && elem != null && elem.constructor === Array && prop !== "<>") {
addStubs(newDesc, elem, prop, false, element, []);
} else {
newDesc[previousProp = prop] = elem;
}
}
}
$$[property] = [globalObject, newDesc];
classes.push(property);
}
}
}
function addStubs(descriptor, array, name, isStatic, originalDescriptor, functions) {
var f, funcs = [originalDescriptor[name] = descriptor[name] = f = array[0]];
f.$stubName = name;
functions.push(name);
for (var index = 0; index < array.length; index += 2) {
f = array[index + 1];
if (typeof f != "function") break;
f.$stubName = array[index + 2];
funcs.push(f);
if (f.$stubName) {
originalDescriptor[f.$stubName] = descriptor[f.$stubName] = f;
functions.push(f.$stubName);
}
}
for (var i = 0; i < funcs.length; index++, i++) {
funcs[i].$callName = array[index + 1];
}
var getterStubName = array[++index];
array = array.slice(++index);
var requiredParameterInfo = array[0];
var requiredParameterCount = requiredParameterInfo >> 1;
var isAccessor = (requiredParameterInfo & 1) === 1;
var isSetter = requiredParameterInfo === 3;
var isGetter = requiredParameterInfo === 1;
var optionalParameterInfo = array[1];
var optionalParameterCount = optionalParameterInfo >> 1;
var optionalParametersAreNamed = (optionalParameterInfo & 1) === 1;
var isIntercepted = requiredParameterCount + optionalParameterCount != funcs[0].length;
var functionTypeIndex = array[2];
var unmangledNameIndex = 2 * optionalParameterCount + requiredParameterCount + 3;
var isReflectable = array.length > unmangledNameIndex;
if (getterStubName) {
f = tearOff(funcs, array, isStatic, name, isIntercepted);
f.getterStub = true;
if (isStatic) init.globalFunctions[name] = f;
originalDescriptor[getterStubName] = descriptor[getterStubName] = f;
funcs.push(f);
if (getterStubName) functions.push(getterStubName);
f.$stubName = getterStubName;
f.$callName = null;
if (isIntercepted) init.interceptedNames[getterStubName] = true;
}
if (isReflectable) {
for (var i = 0; i < funcs.length; i++) {
funcs[i].$reflectable = 1;
funcs[i].$reflectionInfo = array;
}
var mangledNames = isStatic ? init.mangledGlobalNames : init.mangledNames;
var unmangledName = array[unmangledNameIndex];
var reflectionName = unmangledName;
if (getterStubName) mangledNames[getterStubName] = reflectionName;
if (isSetter) {
reflectionName += "=";
} else if (!isGetter) {
reflectionName += ":" + requiredParameterCount + ":" + optionalParameterCount;
}
mangledNames[name] = reflectionName;
funcs[0].$reflectionName = reflectionName;
funcs[0].$metadataIndex = unmangledNameIndex + 1;
if (optionalParameterCount) descriptor[unmangledName + "*"] = funcs[0];
}
}
function tearOffGetterNoCsp(funcs, reflectionInfo, name, isIntercepted) {
return isIntercepted
? new Function("funcs", "reflectionInfo", "name", "H", "c",
"return function tearOff_" + name + (functionCounter++)+ "(x) {" +
"if (c === null) c = H.closureFromTearOff(" +
"this, funcs, reflectionInfo, false, [x], name);" +
"return new c(this, funcs[0], x, name);" +
"}")(funcs, reflectionInfo, name, H, null)
: new Function("funcs", "reflectionInfo", "name", "H", "c",
"return function tearOff_" + name + (functionCounter++)+ "() {" +
"if (c === null) c = H.closureFromTearOff(" +
"this, funcs, reflectionInfo, false, [], name);" +
"return new c(this, funcs[0], null, name);" +
"}")(funcs, reflectionInfo, name, H, null)
}
function tearOffGetterCsp(funcs, reflectionInfo, name, isIntercepted) {
var cache = null;
return isIntercepted
? function(x) {
if (cache === null) cache = H.closureFromTearOff(this, funcs, reflectionInfo, false, [x], name);
return new cache(this, funcs[0], x, name)
}
: function() {
if (cache === null) cache = H.closureFromTearOff(this, funcs, reflectionInfo, false, [], name);
return new cache(this, funcs[0], null, name)
}
}
function tearOff(funcs, reflectionInfo, isStatic, name, isIntercepted) {
var cache;
return isStatic
? function() {
if (cache === void 0) cache = H.closureFromTearOff(this, funcs, reflectionInfo, true, [], name).prototype;
return cache;
}
: tearOffGetter(funcs, reflectionInfo, name, isIntercepted);
}
var functionCounter = 0;
var tearOffGetter = (typeof dart_precompiled == "function")
? tearOffGetterCsp : tearOffGetterNoCsp;
if (!init.libraries) init.libraries = [];
if (!init.mangledNames) init.mangledNames = map();
if (!init.mangledGlobalNames) init.mangledGlobalNames = map();
if (!init.statics) init.statics = map();
if (!init.typeInformation) init.typeInformation = map();
if (!init.globalFunctions) init.globalFunctions = map();
if (!init.interceptedNames) init.interceptedNames = map();
var libraries = init.libraries;
var mangledNames = init.mangledNames;
var mangledGlobalNames = init.mangledGlobalNames;
var hasOwnProperty = Object.prototype.hasOwnProperty;
var length = reflectionData.length;
for (var i = 0; i < length; i++) {
var data = reflectionData[i];
var name = data[0];
var uri = data[1];
var metadata = data[2];
var globalObject = data[3];
var descriptor = data[4];
var isRoot = !!data[5];
var fields = descriptor && descriptor["^"];
var classes = [];
var functions = [];
processStatics(descriptor);
libraries.push([name, uri, classes, functions, metadata, fields, isRoot,
globalObject]);
}
})
([
["Repo", "repo.dart", , F, {
"^": "",
main: function() {
return C.Type_Jeh;
}
},
1],
["_js_helper", "dart:_js_helper", , H, {
"^": "",
createRuntimeType: function($name) {
return new H.TypeImpl($name, null);
},
TypeImpl: {
"^": "Object;_typeName,_unmangledName"
}
}],
["dart.core", "dart:core", , P, {
"^": "",
Null: {
"^": "Object;"
},
Object: {
"^": ";"
}
}],
]);
Isolate.$finishClasses($$, $, null);
$$ = null;
// Runtime type support
// getInterceptor methods
C.Type_Jeh = H.createRuntimeType('Repo');
$.libraries_to_load = {};
$.Closure_functionCounter = 0;
$.BoundClosure_selfFieldNameCache = null;
$.BoundClosure_receiverFieldNameCache = null;
init.functionAliases = {};
;
init.metadata = [];
$ = null;
Isolate = Isolate.$finishIsolateConstructor(Isolate);
$ = new Isolate();
function convertToFastObject(properties) {
function MyClass() {};
MyClass.prototype = properties;
new MyClass();
return properties;
}
A = convertToFastObject(A);
B = convertToFastObject(B);
C = convertToFastObject(C);
D = convertToFastObject(D);
E = convertToFastObject(E);
F = convertToFastObject(F);
G = convertToFastObject(G);
H = convertToFastObject(H);
J = convertToFastObject(J);
K = convertToFastObject(K);
L = convertToFastObject(L);
M = convertToFastObject(M);
N = convertToFastObject(N);
O = convertToFastObject(O);
P = convertToFastObject(P);
Q = convertToFastObject(Q);
R = convertToFastObject(R);
S = convertToFastObject(S);
T = convertToFastObject(T);
U = convertToFastObject(U);
V = convertToFastObject(V);
W = convertToFastObject(W);
X = convertToFastObject(X);
Y = convertToFastObject(Y);
Z = convertToFastObject(Z);
// BEGIN invoke [main].
;(function (callback) {
if (typeof document === "undefined") {
callback(null);
return;
}
if (document.currentScript) {
callback(document.currentScript);
return;
}
var scripts = document.scripts;
function onLoad(event) {
for (var i = 0; i < scripts.length; ++i) {
scripts[i].removeEventListener("load", onLoad, false);
}
callback(event.target);
}
for (var i = 0; i < scripts.length; ++i) {
scripts[i].addEventListener("load", onLoad, false);
}
})(function(currentScript) {
init.currentScript = currentScript;
if (typeof dartMainRunner === "function") {
dartMainRunner(F.main, []);
} else {
F.main([]);
}
});
// END invoke [main].
function init() {
Isolate.$isolateProperties = {};
function generateAccessor(fieldDescriptor, accessors, cls) {
var fieldInformation = fieldDescriptor.split("-");
var field = fieldInformation[0];
var len = field.length;
var code = field.charCodeAt(len - 1);
var reflectable;
if (fieldInformation.length > 1)
reflectable = true;
else
reflectable = false;
code = code >= 60 && code <= 64 ? code - 59 : code >= 123 && code <= 126 ? code - 117 : code >= 37 && code <= 43 ? code - 27 : 0;
if (code) {
var getterCode = code & 3;
var setterCode = code >> 2;
var accessorName = field = field.substring(0, len - 1);
var divider = field.indexOf(":");
if (divider > 0) {
accessorName = field.substring(0, divider);
field = field.substring(divider + 1);
}
if (getterCode) {
var args = getterCode & 2 ? "receiver" : "";
var receiver = getterCode & 1 ? "this" : "receiver";
var body = "return " + receiver + "." + field;
var property = cls + ".prototype.get$" + accessorName + "=";
var fn = "function(" + args + "){" + body + "}";
if (reflectable)
accessors.push(property + "$reflectable(" + fn + ");\n");
else
accessors.push(property + fn + ";\n");
}
if (setterCode) {
var args = setterCode & 2 ? "receiver, value" : "value";
var receiver = setterCode & 1 ? "this" : "receiver";
var body = receiver + "." + field + " = value";
var property = cls + ".prototype.set$" + accessorName + "=";
var fn = "function(" + args + "){" + body + "}";
if (reflectable)
accessors.push(property + "$reflectable(" + fn + ");\n");
else
accessors.push(property + fn + ";\n");
}
}
return field;
}
Isolate.$isolateProperties.$generateAccessor = generateAccessor;
function defineClass(name, cls, fields) {
var accessors = [];
var str = "function " + cls + "(";
var body = "";
for (var i = 0; i < fields.length; i++) {
if (i != 0)
str += ", ";
var field = generateAccessor(fields[i], accessors, cls);
var parameter = "parameter_" + field;
str += parameter;
body += "this." + field + " = " + parameter + ";\n";
}
str += ") {\n" + body + "}\n";
str += cls + ".builtin$cls=\"" + name + "\";\n";
str += "$desc=$collectedClasses." + cls + ";\n";
str += "if($desc instanceof Array) $desc = $desc[1];\n";
str += cls + ".prototype = $desc;\n";
if (typeof defineClass.name != "string") {
str += cls + ".name=\"" + cls + "\";\n";
}
str += accessors.join("");
return str;
}
var inheritFrom = function() {
function tmp() {
}
var hasOwnProperty = Object.prototype.hasOwnProperty;
return function(constructor, superConstructor) {
tmp.prototype = superConstructor.prototype;
var object = new tmp();
var properties = constructor.prototype;
for (var member in properties)
if (hasOwnProperty.call(properties, member))
object[member] = properties[member];
object.constructor = constructor;
constructor.prototype = object;
return object;
};
}();
Isolate.$finishClasses = function(collectedClasses, isolateProperties, existingIsolateProperties) {
var pendingClasses = {};
if (!init.allClasses)
init.allClasses = {};
var allClasses = init.allClasses;
var hasOwnProperty = Object.prototype.hasOwnProperty;
if (typeof dart_precompiled == "function") {
var constructors = dart_precompiled(collectedClasses);
} else {
var combinedConstructorFunction = "function $reflectable(fn){fn.$reflectable=1;return fn};\n" + "var $desc;\n";
var constructorsList = [];
}
for (var cls in collectedClasses) {
if (hasOwnProperty.call(collectedClasses, cls)) {
var desc = collectedClasses[cls];
if (desc instanceof Array)
desc = desc[1];
var classData = desc["^"], supr, name = cls, fields = classData;
if (typeof classData == "string") {
var split = classData.split("/");
if (split.length == 2) {
name = split[0];
fields = split[1];
}
}
var s = fields.split(";");
fields = s[1] == "" ? [] : s[1].split(",");
supr = s[0];
split = supr.split(":");
if (split.length == 2) {
supr = split[0];
var functionSignature = split[1];
if (functionSignature)
desc.$signature = function(s) {
return function() {
return init.metadata[s];
};
}(functionSignature);
}
if (typeof dart_precompiled != "function") {
combinedConstructorFunction += defineClass(name, cls, fields);
constructorsList.push(cls);
}
if (supr)
pendingClasses[cls] = supr;
}
}
if (typeof dart_precompiled != "function") {
combinedConstructorFunction += "return [\n " + constructorsList.join(",\n ") + "\n]";
var constructors = new Function("$collectedClasses", combinedConstructorFunction)(collectedClasses);
combinedConstructorFunction = null;
}
for (var i = 0; i < constructors.length; i++) {
var constructor = constructors[i];
var cls = constructor.name;
var desc = collectedClasses[cls];
var globalObject = isolateProperties;
if (desc instanceof Array) {
globalObject = desc[0] || isolateProperties;
desc = desc[1];
}
allClasses[cls] = constructor;
globalObject[cls] = constructor;
}
constructors = null;
var finishedClasses = {};
init.interceptorsByTag = Object.create(null);
init.leafTags = {};
function finishClass(cls) {
var hasOwnProperty = Object.prototype.hasOwnProperty;
if (hasOwnProperty.call(finishedClasses, cls))
return;
finishedClasses[cls] = true;
var superclass = pendingClasses[cls];
if (!superclass || typeof superclass != "string")
return;
finishClass(superclass);
var constructor = allClasses[cls];
var superConstructor = allClasses[superclass];
if (!superConstructor)
superConstructor = existingIsolateProperties[superclass];
var prototype = inheritFrom(constructor, superConstructor);
}
for (var cls in pendingClasses)
finishClass(cls);
};
Isolate.$lazy = function(prototype, staticName, fieldName, getterName, lazyValue) {
var sentinelUndefined = {};
var sentinelInProgress = {};
prototype[fieldName] = sentinelUndefined;
prototype[getterName] = function() {
var result = $[fieldName];
try {
if (result === sentinelUndefined) {
$[fieldName] = sentinelInProgress;
try {
result = $[fieldName] = lazyValue();
} finally {
if (result === sentinelUndefined) {
if ($[fieldName] === sentinelInProgress) {
$[fieldName] = null;
}
}
}
} else {
if (result === sentinelInProgress)
H.throwCyclicInit(staticName);
}
return result;
} finally {
$[getterName] = function() {
return this[fieldName];
};
}
};
};
Isolate.$finishIsolateConstructor = function(oldIsolate) {
var isolateProperties = oldIsolate.$isolateProperties;
function Isolate() {
var hasOwnProperty = Object.prototype.hasOwnProperty;
for (var staticName in isolateProperties)
if (hasOwnProperty.call(isolateProperties, staticName))
this[staticName] = isolateProperties[staticName];
function ForceEfficientMap() {
}
ForceEfficientMap.prototype = this;
new ForceEfficientMap();
}
Isolate.prototype = oldIsolate.prototype;
Isolate.prototype.constructor = Isolate;
Isolate.$isolateProperties = isolateProperties;
Isolate.$finishClasses = oldIsolate.$finishClasses;
return Isolate;
};
}
})()
//# sourceMappingURL=out.js.map
//@ sourceMappingURL=out.js.map
Und das ist es, ich habe weggeworfen Dart, weil ich nicht wusste, was ich mit generierten JS-Datei zu tun habe, auch hatte ich Angst vor möglicherweise viel Zeit für das Halten der resultierenden Bibliothek Schnittstelle sauber und ähnlich einer, den ich mit JavaScript bin.
Die Frage (n)
- Wie belichten wir Klassendefinitionen in Dart erstellt und später in JavaScript verwenden?
- Glaubst du, es lohnt sich, in Dart zu gehen, wenn fast alle potenziellen Bibliotheksbenutzer stattdessen die JS-Version verwenden? (Die Verwendung von Dart ist aufgrund von Unterschieden in den Community-Größen bereits nicht gut für mich, das bedeutet, dass weniger Leute es einfacher finden, zu meiner Bibliothek beizutragen)
- Was kann ich Ihrer Meinung nach tun?
https: // GitHub. com/dart-lang/dev_compiler wird für diesen Zweck gebaut. Es kann bereits verwendet werden, ist aber noch nicht freigegeben. Einige haben berichtet, dass es bereits für ihre Anforderungen gearbeitet hat. –