Merge pull request #92 from huggingface/fix-bpe-tokenizer

Fix BPETokenizer

bindings/node/lib/bindings/pre-tokenizers.d.ts

@@ -29,6 +29,13 @@ export function byteLevelAlphabet(): string[];
  */
 export function whitespacePreTokenizer(): PreTokenizer;
 
+/**
+ * Returns a WhitespaceSplit PreTokenizer
+ * This pre-tokenizer simply splits on whitespaces only. Works almost like the `.split(' ')`
+ * function, except that it accounts for multiple consecutive spaces
+ */
+export function whitespaceSplitPreTokenizer(): PreTokenizer;
+
 /**
  * Returns a new Bert PreTokenizer.
  * This pre-tokenizer splits tokens on spaces, and also on punctuation.

bindings/node/lib/bindings/pre-tokenizers.js

@@ -1,9 +1,10 @@
 var native = require('./native');
 
 module.exports = {
-  byteLevelPreTokenizer:  native.pre_tokenizers_ByteLevel,
-  byteLevelAlphabet:      native.pre_tokenizers_ByteLevel_Alphabet,
-  whitespacePreTokenizer: native.pre_tokenizers_Whitespace,
-  bertPreTokenizer:       native.pre_tokenizers_BertPreTokenizer,
-  metaspacePreTokenizer:  native.pre_tokenizers_Metaspace
+  byteLevelPreTokenizer:       native.pre_tokenizers_ByteLevel,
+  byteLevelAlphabet:           native.pre_tokenizers_ByteLevel_Alphabet,
+  whitespacePreTokenizer:      native.pre_tokenizers_Whitespace,
+  whitespaceSplitPreTokenizer: native.pre_tokenizers_WhitespaceSplit,
+  bertPreTokenizer:            native.pre_tokenizers_BertPreTokenizer,
+  metaspacePreTokenizer:       native.pre_tokenizers_Metaspace
 };

bindings/node/lib/tokenizers/bpe.tokenizer.ts

@@ -3,7 +3,7 @@ import { BaseTokenizer } from "./base.tokenizer";
 import { Model, bpe } from "../bindings/models";
 import { Tokenizer } from "../bindings/tokenizer";
 import { sequenceNormalizer, nfkcNormalizer, lowercaseNormalizer } from "../bindings/normalizers";
-import { whitespacePreTokenizer } from "../bindings/pre-tokenizers";
+import { whitespaceSplitPreTokenizer } from "../bindings/pre-tokenizers";
 import { bpeDecoder } from "../bindings/decoders";
 import { bpeTrainer } from "../bindings/trainers";
 
@@ -103,7 +103,7 @@ export class BPETokenizer extends BaseTokenizer {
 
     const normalizer = sequenceNormalizer([nfkcNormalizer(), lowercaseNormalizer()]);
     tokenizer.setNormalizer(normalizer);
-    tokenizer.setPreTokenizer(whitespacePreTokenizer());
+    tokenizer.setPreTokenizer(whitespaceSplitPreTokenizer());
 
     const decoder = bpeDecoder(mergedOptions.suffix);
     tokenizer.setDecoder(decoder);

bindings/node/native/src/pre_tokenizers.rs

@@ -62,6 +62,17 @@ fn whitespace(mut cx: FunctionContext) -> JsResult<JsPreTokenizer> {
     Ok(pretok)
 }
 
+/// whitespace_split()
+fn whitespace_split(mut cx: FunctionContext) -> JsResult<JsPreTokenizer> {
+    let mut pretok = JsPreTokenizer::new::<_, JsPreTokenizer, _>(&mut cx, vec![])?;
+    let guard = cx.lock();
+    pretok
+        .borrow_mut(&guard)
+        .pretok
+        .to_owned(Box::new(tk::pre_tokenizers::whitespace::WhitespaceSplit));
+    Ok(pretok)
+}
+
 /// bert_pre_tokenizer()
 fn bert_pre_tokenizer(mut cx: FunctionContext) -> JsResult<JsPreTokenizer> {
     let mut pretok = JsPreTokenizer::new::<_, JsPreTokenizer, _>(&mut cx, vec![])?;
@@ -105,6 +116,7 @@ pub fn register(m: &mut ModuleContext, prefix: &str) -> NeonResult<()> {
         byte_level_alphabet,
     )?;
     m.export_function(&format!("{}_Whitespace", prefix), whitespace)?;
+    m.export_function(&format!("{}_WhitespaceSplit", prefix), whitespace_split)?;
     m.export_function(&format!("{}_BertPreTokenizer", prefix), bert_pre_tokenizer)?;
     m.export_function(&format!("{}_Metaspace", prefix), metaspace)?;
     Ok(())

bindings/python/src/lib.rs

@@ -37,6 +37,7 @@ fn pre_tokenizers(_py: Python, m: &PyModule) -> PyResult<()> {
     m.add_class::<pre_tokenizers::PreTokenizer>()?;
     m.add_class::<pre_tokenizers::ByteLevel>()?;
     m.add_class::<pre_tokenizers::Whitespace>()?;
+    m.add_class::<pre_tokenizers::WhitespaceSplit>()?;
     m.add_class::<pre_tokenizers::BertPreTokenizer>()?;
     m.add_class::<pre_tokenizers::Metaspace>()?;
     Ok(())

bindings/python/src/pre_tokenizers.rs

@@ -73,6 +73,18 @@ impl Whitespace {
     }
 }
 
+#[pyclass]
+pub struct WhitespaceSplit {}
+#[pymethods]
+impl WhitespaceSplit {
+    #[staticmethod]
+    fn new() -> PyResult<PreTokenizer> {
+        Ok(PreTokenizer {
+            pretok: Container::Owned(Box::new(tk::pre_tokenizers::whitespace::WhitespaceSplit)),
+        })
+    }
+}
+
 #[pyclass]
 pub struct BertPreTokenizer {}
 #[pymethods]

bindings/python/tokenizers/implementations/bpe.py

@@ -30,7 +30,7 @@ class BPETokenizer(BaseTokenizer):
             NFKC.new(),
             Lowercase.new()
         ])
-        tokenizer.pre_tokenizer = pre_tokenizers.Whitespace.new()
+        tokenizer.pre_tokenizer = pre_tokenizers.WhitespaceSplit.new()
         tokenizer.decoder = decoders.BPEDecoder.new(suffix=suffix)
 
         parameters = {

bindings/python/tokenizers/pre_tokenizers/__init__.py

@@ -3,5 +3,6 @@ from .. import pre_tokenizers
 PreTokenizer = pre_tokenizers.PreTokenizer
 ByteLevel = pre_tokenizers.ByteLevel
 Whitespace = pre_tokenizers.Whitespace
+WhitespaceSplit = pre_tokenizers.WhitespaceSplit
 BertPreTokenizer = pre_tokenizers.BertPreTokenizer
 Metaspace = pre_tokenizers.Metaspace

bindings/python/tokenizers/pre_tokenizers/__init__.pyi

@@ -55,6 +55,17 @@ class Whitespace:
         """ Instantiate a new Whitespace PreTokenizer """
         pass
 
+class WhitespaceSplit:
+    """ Whitespace PreTokenizer
+
+    This pre-tokenizer simply splits on the whitespace. Works like `.split()`
+    """
+
+    @staticmethod
+    def new() -> PreTokenizer:
+        """ Instantiate a new WhitespaceSplit PreTokenizer """
+        pass
+
 class BertPreTokenizer:
     """ BertPreTokenizer
 

tokenizers/src/pre_tokenizers/whitespace.rs

@@ -26,9 +26,36 @@ impl PreTokenizer for Whitespace {
     }
 }
 
+pub struct WhitespaceSplit;
+impl PreTokenizer for WhitespaceSplit {
+    fn pre_tokenize(&self, s: &str) -> Result<Vec<(String, Offsets)>> {
+        let mut words = vec![];
+        let mut word = Vec::with_capacity(1000);
+        let mut offset = 0;
+
+        s.chars().for_each(|c| {
+            if c.is_whitespace() {
+                if !word.is_empty() {
+                    let offsets = (offset - word.len(), offset);
+                    words.push((word.drain(0..).collect::<String>(), offsets));
+                }
+            } else {
+                word.push(c);
+            }
+            offset += 1;
+        });
+        if !word.is_empty() {
+            let offsets = (offset - word.len(), offset);
+            words.push((word.drain(0..).collect::<String>(), offsets));
+        }
+
+        Ok(words)
+    }
+}
+
 #[cfg(test)]
 mod tests {
-    use super::Whitespace;
+    use super::*;
     use crate::tokenizer::PreTokenizer;
 
     #[test]
@@ -58,4 +85,26 @@ mod tests {
             assert_eq!(pretok.pre_tokenize(s).unwrap(), res);
         }
     }
+
+    #[test]
+    fn whitespace_split() {
+        let tests = vec![
+            (
+                "Hey man!",
+                vec![("Hey".into(), (0, 3)), ("man!".into(), (4, 8))],
+            ),
+            (
+                "Hey, man, Good?",
+                vec![
+                    ("Hey,".into(), (0, 4)),
+                    ("man,".into(), (5, 9)),
+                    ("Good?".into(), (10, 15)),
+                ],
+            ),
+        ];
+        let pretok = WhitespaceSplit;
+        for (s, res) in tests {
+            assert_eq!(pretok.pre_tokenize(s).unwrap(), res);
+        }
+    }
 }