Function remember 

pub fn remember<F: Fs>(
    db: &mut GraphDb<F>,
    input: &RememberInput<'_>,
) -> Result<RememberReport>

Write input as a Note, describing whatever it names along the way.

Validated before anything is written: text must be [MIN_TEXT_CHARS]..=[MAX_TEXT_CHARS] characters after trimming, and kind must be one of NOTE_KINDS. Unlike the code-graph remember 0.7 deleted, an unknown about key is never an error — see the module docs. A key that is empty or only whitespace is one: in about, as an entities[].key or as a fact’s subject or object it refuses the whole call, naming the argument and its position, and nothing is written. So is an entities[].label or a fact’s predicate with nothing in it.

The note’s key is "note:" followed by 16 hex characters of a stable 64-bit hash of ts and text (see [note_key]), so remembering the same text at the same ts again returns the same key without writing a second node.

Also ensures full-text search is enabled on Note.text, so a store whose very first write is a remember call can still be recalled from.