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Io语言'应用参数'(Io language 'apply arguments')

 在Io编程语言中，是否有相当于lisp的apply函数。  
 所以例如我有一个方法来包装writeln：  
mymeth := method(
              //do some extra stuff

             writeln(call message arguments))
)
 
 目前这只是打印清单，并没有评估它的内容，就好像它是自己的参数一样。 

In the Io programming language, is there an equivalent to lisp's apply function. 
So for example I have a method to wrap writeln : 
mymeth := method(
              //do some extra stuff

             writeln(call message arguments))
)
 
At the moment this just prints the list, and doesn't evaluate it's contents as if they were it's own args.

原文：https://stackoverflow.com/questions/4419779

更新时间：2023-02-23 12:02

最满意答案

 Nimrand回答你的问题（缺少catch ），但这里是你的代码，没有承诺构造函数antipattern ：  
function getDataFromServer() {
  var result = [];

  function fetchData(nextPageToken) {
    return server.getData(nextPageToken).then(function(response) {
      result.push(response.data);
      if (response.nextPageToken) {
        return fetchData(response.nextPageToken);
      } else {
        return result;
      }
    });
  }
  return fetchData(null);
}

getDataFromServer().then(function(result) {
  console.log(result);
})
.catch(function(e) {
  console.error(e);
});
 
 正如你所看到的，递归在承诺方面很有效。  
 
 
  
  var console = { log: function(msg) { div.innerHTML += "<p>"+ msg +"</p>"; }};

var responses = [
  { data: 1001, nextPageToken: 1 },
  { data: 1002, nextPageToken: 2 },
  { data: 1003, nextPageToken: 3 },
  { data: 1004, nextPageToken: 4 },
  { data: 1005, nextPageToken: 0 },
];

var server = {
  getData: function(token) {
    return new Promise(function(resolve) { resolve(responses[token]); });
  }
};

function getDataFromServer() {
  var result = [];

  function fetchData(nextPageToken) {
    return server.getData(nextPageToken).then(function(response) {
      result.push(response.data);
      if (response.nextPageToken) {
        return fetchData(response.nextPageToken);
      } else {
        return result;
      }
    });
  }
  return fetchData(0);
}

getDataFromServer().then(function(result) {
  console.log(result);
})
.catch(function(e) { console.log(e); }); 
  <div id="div"></div> 
  
 

Nimrand answers your question (missing catch), but here is your code without the promise constructor antipattern: 
function getDataFromServer() {
  var result = [];

  function fetchData(nextPageToken) {
    return server.getData(nextPageToken).then(function(response) {
      result.push(response.data);
      if (response.nextPageToken) {
        return fetchData(response.nextPageToken);
      } else {
        return result;
      }
    });
  }
  return fetchData(null);
}

getDataFromServer().then(function(result) {
  console.log(result);
})
.catch(function(e) {
  console.error(e);
});
 
As you can see, recursion works great with promises. 
 
 
  
  var console = { log: function(msg) { div.innerHTML += "<p>"+ msg +"</p>"; }};

var responses = [
  { data: 1001, nextPageToken: 1 },
  { data: 1002, nextPageToken: 2 },
  { data: 1003, nextPageToken: 3 },
  { data: 1004, nextPageToken: 4 },
  { data: 1005, nextPageToken: 0 },
];

var server = {
  getData: function(token) {
    return new Promise(function(resolve) { resolve(responses[token]); });
  }
};

function getDataFromServer() {
  var result = [];

  function fetchData(nextPageToken) {
    return server.getData(nextPageToken).then(function(response) {
      result.push(response.data);
      if (response.nextPageToken) {
        return fetchData(response.nextPageToken);
      } else {
        return result;
      }
    });
  }
  return fetchData(0);
}

getDataFromServer().then(function(result) {
  console.log(result);
})
.catch(function(e) { console.log(e); }); 
  <div id="div"></div>

Io语言'应用参数'(Io language 'apply arguments')

最满意答案

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