Admin
1
lets say we have library that reads file line by line like this:
var lines = lib.open('file.txt');
lines.on('line', function(line) {
console.log(line);
});
Is there any way to wrap the code and create generator that could be used with "for of" loop:
for (let line of lines) {
console.log(line);
}
lines.on('line', function(line) {
yield line; // doesnt work inside the function
console.log(line);
});
If i yield inside the function it doesn't work.
Thanks
You can use for await of loop on stream
async function read(lines) {
for await (const line of lines) {
console.log('>>> ',line);
}
}
var lines = lib.open('file.txt');
read(lines)
From chunks to lines
The following function takes an async iterable over strings and returns an async iterable over lines:
async function* chunksToLines(chunksAsync) {
let previous = '';
for await (const chunk of chunksAsync) {
previous += chunk;
let eolIndex;
while ((eolIndex = previous.indexOf('\n')) >= 0) {
// line includes the EOL
const line = previous.slice(0, eolIndex+1);
yield line;
previous = previous.slice(eolIndex+1);
}
}
if (previous.length > 0) {
yield previous;
}
}
Read this out for more details:
