Function flattenDestructuringBinding

test/fixtures/snapshot/typescript.js:91120–91184

* Flattens a VariableDeclaration or ParameterDeclaration to one or more variable declarations. * * @param node The node to flatten. * @param visitor An optional visitor used to visit initializers. * @param context The transformation context. * @param boundValue The value bou

(node, visitor, context, level, rval, hoistTempVariables, skipInitializer)

     * @param level Indicates the extent to which flattening should occur.
     */
    function flattenDestructuringBinding(node, visitor, context, level, rval, hoistTempVariables, skipInitializer) {
        if (hoistTempVariables === void 0) { hoistTempVariables = false; }
        var pendingExpressions;
        var pendingDeclarations = [];
        var declarations = [];
        var flattenContext = {
            context: context,
            level: level,
            downlevelIteration: !!context.getCompilerOptions().downlevelIteration,
            hoistTempVariables: hoistTempVariables,
            emitExpression: emitExpression,
            emitBindingOrAssignment: emitBindingOrAssignment,
            createArrayBindingOrAssignmentPattern: function (elements) { return makeArrayBindingPattern(context.factory, elements); },
            createObjectBindingOrAssignmentPattern: function (elements) { return makeObjectBindingPattern(context.factory, elements); },
            createArrayBindingOrAssignmentElement: function (name) { return makeBindingElement(context.factory, name); },
            visitor: visitor
        };
        if (ts.isVariableDeclaration(node)) {
            var initializer = ts.getInitializerOfBindingOrAssignmentElement(node);
            if (initializer && (ts.isIdentifier(initializer) && bindingOrAssignmentElementAssignsToName(node, initializer.escapedText) ||
                bindingOrAssignmentElementContainsNonLiteralComputedName(node))) {
                // If the right-hand value of the assignment is also an assignment target then
                // we need to cache the right-hand value.
                initializer = ensureIdentifier(flattenContext, ts.visitNode(initializer, flattenContext.visitor), /*reuseIdentifierExpressions*/ false, initializer);
                node = context.factory.updateVariableDeclaration(node, node.name, /*exclamationToken*/ undefined, /*type*/ undefined, initializer);
            }
        }
        flattenBindingOrAssignmentElement(flattenContext, node, rval, node, skipInitializer);
        if (pendingExpressions) {
            var temp = context.factory.createTempVariable(/*recordTempVariable*/ undefined);
            if (hoistTempVariables) {
                var value = context.factory.inlineExpressions(pendingExpressions);
                pendingExpressions = undefined;
                emitBindingOrAssignment(temp, value, /*location*/ undefined, /*original*/ undefined);
            }
            else {
                context.hoistVariableDeclaration(temp);
                var pendingDeclaration = ts.last(pendingDeclarations);
                pendingDeclaration.pendingExpressions = ts.append(pendingDeclaration.pendingExpressions, context.factory.createAssignment(temp, pendingDeclaration.value));
                ts.addRange(pendingDeclaration.pendingExpressions, pendingExpressions);
                pendingDeclaration.value = temp;
            }
        }
        for (var _i = 0, pendingDeclarations_1 = pendingDeclarations; _i < pendingDeclarations_1.length; _i++) {
            var _a = pendingDeclarations_1[_i], pendingExpressions_1 = _a.pendingExpressions, name = _a.name, value = _a.value, location = _a.location, original = _a.original;
            var variable = context.factory.createVariableDeclaration(name, 
            /*exclamationToken*/ undefined, 
            /*type*/ undefined, pendingExpressions_1 ? context.factory.inlineExpressions(ts.append(pendingExpressions_1, value)) : value);
            variable.original = original;
            ts.setTextRange(variable, location);
            declarations.push(variable);
        }
        return declarations;
        function emitExpression(value) {
            pendingExpressions = ts.append(pendingExpressions, value);
        }
        function emitBindingOrAssignment(target, value, location, original) {
            ts.Debug.assertNode(target, ts.isBindingName);