I have a string that I want to transform into a dictionary, the string looks like this:

const str = '::student{name="this is the name" age="21" faculty="some faculty"}'

I want to transform that string into a dictionary that looks like this:

const dic = {
  "name": "this is the name",
  "age": "21",
  "faculty": "some faculty"
}

So the string is formated in this was ::name{parameters...} and can have any parameters, not only name, faculty, ... How can I format any string that looks like that and transform it into a dictionary?

Also Is there a way to check that the current string I'm parsing follow this structure ::name{parameters...}, that way I can throw an error when it does not.

Any help would be greatly appreciated!

CodePudding user response：

Assuming that you only have alphanumeric and spaces or an empty string within the parentheses of the values, and there is never a space between the key and value in key="value" you can match with the following regular expression and then iterate over it to construct your desired object.

const str = '::student{name="this is the name" age="21" faculty="some faculty"}'
const matches = str.match(/[\w] \=\"[\w\s]*(?=")/g)
const result = {}
matches.forEach(match => {
  const [key, value] = match.split('="')
  result[key] = value
})
console.log(result)

The regex is composed of the following parts:

You can use https://regexr.com to experiment with your regular expressions. Depending on the string to process, you'll need to refine your regex.

CodePudding user response：

This example uses exec to look for matches in the string using a regular expression.

const str = '::student{name="this is the name" age="21" faculty="some faculty"}';

const regex = /([a-z] )="([a-z0-9 ?] )"/g;

let match, output = {};

while (match = regex.exec(str)) {
  output[match[1]] = match[2];
}

console.log(output);

CodePudding user response：

If not exist a unique pattern, it is hard, but when pattern is the same, you can split the string:

  var str  = '::student{name="this is the name" age="21" faculty="some faculty"}'

  console.log(createObj(str));


  function createObj(myString){
    if(myString.search("::") !== 0 && myString.search("{}") === -1 && myString.search("}") === -1){
      console.log("format error")
      return null;
    }

    var a = myString.split("{")[1];
    var c = a.replace('{','').replace('}','');
    if(c.search('= ""') !== -1){
      console.log("format incorrect");
      return null;
    }

    var d = c.split('="')

    var keyValue = [];
    for(item of d){
      var e = item.split('" ')
      if(e.length === 1){
        keyValue.push(e[0].replace('"',''));
      }else{
        for(item2 of e){
          keyValue.push(item2.replace('"',''));
        }
      }
    }

    var myObj = {}
    if(keyValue.length % 2 === 0){
      for(var i = 0; i<keyValue.length; i=i 2){
        myObj[keyValue[i]] = keyValue[i 1]
      }
    }
    return myObj;
  }

CodePudding user response：

You could use 2 patterns. The first pattern to match the format of the string and capture the content between the curly braces in a single capture group. The second pattern to get the key value pairs using 2 capture groups.

For the full match you can use

::\w {([^{}]*)}

• ::\w match :: and 1 word characters
• { Match the opening curly
• ([^{}]*) Capture group 1, match from opening till closing curly
• } Match the closing curly

Regex demo

For the keys and values you can use

(\w )="([^"] )"

• (\w ) Capture group 1, match 1 word chars
• =" Match literally
• ([^"] ) Capture group 2, match from an opening till closing double quote
• " Match closing double quote

Regex demo

const str = '::student{name="this is the name" age="21" faculty="some faculty"}';
const regexFullMatch = /::\w {([^{}]*)}/;
const regexKeyValue = /(\w )="([^"] )"/g;
const m = str.match(regexFullMatch);

if (m) {
  dic = Object.fromEntries(
    Array.from(m[1].matchAll(regexKeyValue), v => [v[1], v[2]])
  );
  console.log(dic)
}