24 function walk(ast, func, depthFirst) {  argument
25   if (!(ast instanceof nodes.Node)) {
26     return ast;
29     var astT = func(ast);
30     if (astT && astT !== ast) {
34   if (ast instanceof nodes.NodeList) {
35     var children = mapCOW(ast.children, function (node) {
38     if (children !== ast.children) {
39       ast = new nodes[ast.typename](ast.lineno, ast.colno, children);
41   } else if (ast instanceof nodes.CallExtension) {
42     var args = walk(ast.args, func, depthFirst);
43     var contentArgs = mapCOW(ast.contentArgs, function (node) {
46     if (args !== ast.args || contentArgs !== ast.contentArgs) {
47       ast = new nodes[ast.typename](ast.extName, ast.prop, args, contentArgs);
50     var props = ast.fields.map(function (field) {
51       return ast[field];
57       ast = new nodes[ast.typename](ast.lineno, ast.colno);
59         ast[ast.fields[i]] = prop;
63   return depthFirst ? func(ast) || ast : ast;
65 function depthWalk(ast, func) {  argument
66   return walk(ast, func, true);
92 function liftFilters(ast, asyncFilters) {  argument
93   return depthWalk(ast, function (node) {
109 function liftSuper(ast) {  argument
110   return walk(ast, function (blockNode) {
128 function convertStatements(ast) {  argument
129   return depthWalk(ast, function (node) {
152 function cps(ast, asyncFilters) {  argument
153   return convertStatements(liftSuper(liftFilters(ast, asyncFilters)));
155 function transform(ast, asyncFilters) {  argument
156   return cps(ast, asyncFilters || []);