| from __future__ import annotations |
| from typing import Sequence |
| class SimpleEncoder: |
| """Whitespace fallback encoder when BPE unavailable.""" |
| def __init__(self, vocab: dict[str, int] | None = None): |
| self.vocab = vocab or {"<pad>":0,"<unk>":1,"<bos>":2,"<eos>":3} |
| self.id_to_token = {i:t for t,i in self.vocab.items()} |
| self.unk_id = self.vocab.get("<unk>", 1) |
| self.pad_id = self.vocab.get("<pad>", 0) |
| self.bos_id = self.vocab.get("<bos>", 2) |
| self.eos_id = self.vocab.get("<eos>", 3) |
| def encode(self, text: str, add_special: bool = True) -> list[int]: |
| toks = text.split() |
| ids = [self.vocab.get(t, self.unk_id) for t in toks] |
| if add_special: |
| ids = [self.bos_id] + ids + [self.eos_id] |
| return ids |
| def decode(self, ids: Sequence[int], skip_special: bool = True) -> str: |
| special = {self.pad_id, self.bos_id, self.eos_id} |
| toks = [] |
| for i in ids: |
| if skip_special and i in special: continue |
| toks.append(self.id_to_token.get(i, "<unk>")) |
| return " ".join(toks) |
|
|
