Fix fuzzy_term_query() documentation. (#236)

src/query.rs

@@ -61,8 +61,8 @@ impl Query {
  /// * `field_name` - Field name to be searched.
  /// * `text` - String representation of the query term.
  /// * `distance` - (Optional) Edit distance you are going to alow. When not specified, the default is 1.
- /// * `transposition_cost_one` - (Optional) If true, a transposition cost will be 1; otherwise it will be 2. When not specified, the default is true.
- /// * `prefix` - (Optional) If true, only prefix matched results are returned. When not specified, the default is false.
+ /// * `transposition_cost_one` - (Optional) If true, a transposition (swapping) cost will be 1; otherwise it will be 2. When not specified, the default is true.
+ /// * `prefix` - (Optional) If true, prefix levenshtein distance is applied. When not specified, the default is false.
  #[staticmethod]
  #[pyo3(signature = (schema, field_name, text, distance = 1, transposition_cost_one = true, prefix = false))]
  pub(crate) fn fuzzy_term_query(

tests/tantivy_test.py

@@ -775,24 +775,48 @@ def test_all_query(self, ram_index):
  def test_fuzzy_term_query(self, ram_index):
  index = ram_index
  query = Query.fuzzy_term_query(index.schema, "title", "ice")
-
  # the query "ice" should match "mice"
  result = index.searcher().search(query, 10)
  assert len(result.hits) == 1
  _, doc_address = result.hits[0]
  searched_doc = index.searcher().doc(doc_address)
  assert searched_doc["title"] == ["Of Mice and Men"]
-
- def test_fuzzy_term_query_prefix(self, ram_index):
- index = ram_index
- query = Query.fuzzy_term_query(index.schema, "title", "man", prefix=True)
 
- # the query "man" should match both "man" and "men"
+ query = Query.fuzzy_term_query(index.schema, "title", "mna")
+ # the query "mna" should match "man" since the default transposition cost is 1.
+ result = index.searcher().search(query, 10)
+ assert len(result.hits) == 1
+ titles = set()
+ for _, doc_address in result.hits:
+ titles.update(index.searcher().doc(doc_address)["title"])
+ assert titles == {"The Old Man and the Sea"}
+
+ query = Query.fuzzy_term_query(index.schema, "title", "mna", transposition_cost_one=False)
+ # the query "mna" should not match any doc since the default distance is 1 and transposition cost is set to 2.
+ result = index.searcher().search(query, 10)
+ assert len(result.hits) == 0
+
+ query = Query.fuzzy_term_query(index.schema, "title", "mna", distance=2, transposition_cost_one=False)
+ # the query "mna" should match both "man" and "men" since distance is set to 2.
  result = index.searcher().search(query, 10)
  assert len(result.hits) == 2
  titles = set()
  for _, doc_address in result.hits:
  titles.update(index.searcher().doc(doc_address)["title"])
  assert titles == {"The Old Man and the Sea", "Of Mice and Men"}
 
+ query = Query.fuzzy_term_query(index.schema, "title", "fraken")
+ # the query "fraken" should not match any doc.
+ result = index.searcher().search(query, 10)
+ assert len(result.hits) == 0
+
+ query = Query.fuzzy_term_query(index.schema, "title", "fraken", prefix=True)
+ # the query "fraken" should match "franken", the prefix of "frankenstein", with edit distance 1.
+ result = index.searcher().search(query, 10)
+ assert len(result.hits) == 1
+ titles = set()
+ for _, doc_address in result.hits:
+ titles.update(index.searcher().doc(doc_address)["title"])
+ assert titles == {"Frankenstein", "The Modern Prometheus"}
+