101 lines
2.5 KiB
JavaScript
101 lines
2.5 KiB
JavaScript
import callDelegate from "../../helpers/call-delegate";
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import * as util from "../../../util";
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import * as t from "../../../types";
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export function check(node) {
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return t.isFunction(node) && hasDefaults(node);
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}
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var hasDefaults = function (node) {
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for (var i = 0; i < node.params.length; i++) {
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if (!t.isIdentifier(node.params[i])) return true;
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}
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return false;
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};
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var iifeVisitor = {
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enter(node, parent, scope, state) {
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if (!this.isReferencedIdentifier()) return;
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if (!state.scope.hasOwnBinding(node.name)) return;
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if (state.scope.bindingIdentifierEquals(node.name, node)) return;
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state.iife = true;
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this.stop();
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}
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};
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exports.Function = function (node, parent, scope, file) {
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if (!hasDefaults(node)) return;
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t.ensureBlock(node);
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var body = [];
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var argsIdentifier = t.identifier("arguments");
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argsIdentifier._shadowedFunctionLiteral = true;
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var lastNonDefaultParam = 0;
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var state = { iife: false, scope: scope };
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var pushDefNode = function (left, right, i) {
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var defNode = util.template("default-parameter", {
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VARIABLE_NAME: left,
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DEFAULT_VALUE: right,
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ARGUMENT_KEY: t.literal(i),
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ARGUMENTS: argsIdentifier
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}, true);
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file.checkNode(defNode);
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defNode._blockHoist = node.params.length - i;
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body.push(defNode);
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};
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var params = this.get("params");
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for (var i = 0; i < params.length; i++) {
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var param = params[i];
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if (!param.isAssignmentPattern()) {
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if (!param.isRestElement()) {
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lastNonDefaultParam = i + 1;
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}
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if (!param.isIdentifier()) {
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param.traverse(iifeVisitor, state);
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}
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if (file.transformers["es6.spec.blockScoping"].canTransform() && param.isIdentifier()) {
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pushDefNode(param.node, t.identifier("undefined"), i);
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}
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continue;
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}
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var left = param.get("left");
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var right = param.get("right");
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var placeholder = scope.generateUidIdentifier("x");
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placeholder._isDefaultPlaceholder = true;
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node.params[i] = placeholder;
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if (!state.iife) {
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if (right.isIdentifier() && scope.hasOwnBinding(right.node.name)) {
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state.iife = true;
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} else {
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right.traverse(iifeVisitor, state);
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}
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}
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pushDefNode(left.node, right.node, i);
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}
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// we need to cut off all trailing default parameters
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node.params = node.params.slice(0, lastNonDefaultParam);
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if (state.iife) {
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body.push(callDelegate(node, scope));
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node.body = t.blockStatement(body);
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} else {
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node.body.body = body.concat(node.body.body);
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}
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};
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