Something useful
In javascript I found that sometimes it's nice to be able to describe an
object structure in a disconnected way, as a list of paths and values, among
other information, of. Basically this happens when one want in one place to
treat data in a flat manner, but would like a structured representation of that
data in another place.
What I came up with is probably not a unique solution, but I think it has some
elegance to it.
Let's say we have a flat list describing our structure in js:
// We have this
const theData = [
{ path: 'a.b.c', val: 1 },
{ path: 't', val: 2 },
{ path: 'a.b.d.e', val: 3 },
{ path: 'b.c.d', val: 4 },
];
console.log(JSON.stringify(theData,null,2));
// We want this:
const niceObject = {
a: {
b: {
c: 1,
d: {
e: 3
}
}
},
t: 2,
b: {
c: {
d: 4
}
}
};
console.log(JSON.stringify(niceObject,null,2));
// We can do it with this:
function unpack(keys, value, obj) {
const key = keys.shift();
if(keys.length===0) {
obj[key]=value;
return obj;
} else {
if(obj[key]===undefined) {
obj[key]={};
}
return unpack(keys, value, obj[key]);
}
}
// And then just:
const generatedNiceObject = theData.reduce( (obj, item)=>{
unpack( item.path.split('.'), item.val, obj );
return obj;
}, {});
console.log(JSON.stringify(generatedNiceObject,null,2));
