feat(buffer): new api from_{bytes, array, iter} #1254
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| pub fn T::from_iter(iter : Iter[Byte]) -> T { | ||
| let arr = iter.collect() | ||
| T::from_array(arr) | ||
| } |
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How about
for byte in iter {
buf.write_byte(byte)
}And let the T::from_array just use T::from_iter?
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Should let @buffer.new use iter.count() as size_hint? This causes iter to be iterated twice: once for counting and once for writing, not sure if this counting op is cheaper than possible buffer expansion.
I guess arr.length() is cheaper than iter.count(), so I thought from_array should keep it as is.
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iter.count means run the iter once and count each element, which is not what we want. But I'm not quite sure about collecting first and then use T::from_array though. Because when we are collecting, we also have the underlying expansion logic upon the array. Also we would have an extra copy iteration.
So I think it would be reasonable to have two separate implementations instead of one relying on another.
| /// Create a buffer from a bytes. | ||
| pub fn T::from_bytes(bytes : Bytes) -> T { | ||
| let buf = T::new(size_hint=bytes.length()) | ||
| buf.write_bytes(bytes) |
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We should inline write_bytes's logic here, otherwise we would have an uncessary grow_if_necessary check inside the write_bytes.
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