Add substr_scorer (#159)

* Add substr_scorer

Close #158

* Refactor a bit

* Rename to scorer.py

pythonx/clap/fzy.py

@@ -2,17 +2,28 @@
 # -*- coding: utf-8 -*-
 
 import vim
-from clap.fzy_impl import fzy_scorer
 
+from clap.scorer import fzy_scorer, substr_scorer
 
-def fuzzy_match_py(query, candidates):
+
+def apply_score(scorer, query, candidates):
     scored = []
 
     for c in candidates:
-        score, indices = fzy_scorer(query, c)
+        score, indices = scorer(query, c)
         if score != float("-inf"):
             scored.append({'score': score, 'indices': indices, 'text': c})
 
+    return scored
+
+
+def fuzzy_match_py(query, candidates):
+    if ' ' in query:
+        scorer = substr_scorer
+    else:
+        scorer = fzy_scorer
+
+    scored = apply_score(scorer, query, candidates)
     ranked = sorted(scored, key=lambda x: x['score'], reverse=True)
 
     indices = []

pythonx/clap/fzy_impl.py → pythonx/clap/scorer.py

@@ -197,3 +197,22 @@ def fzy_scorer(niddle, haystack):
         return score(niddle, haystack)
     else:
         return SCORE_MIN, None
+
+
+def substr_scorer(niddle, haystack):
+    positions, offset = [], 0
+    niddle, haystack = niddle.lower(), haystack.lower()
+    for niddle in niddle.split(" "):
+        if not niddle:
+            continue
+        offset = haystack.find(niddle, offset)
+        if offset < 0:
+            return float("-inf"), None
+        niddle_len = len(niddle)
+        positions.extend(range(offset, offset + niddle_len))
+        offset += niddle_len
+    if not positions:
+        return 0, positions
+    match_len = positions[-1] + 1 - positions[0]
+    return -match_len + 2 / (positions[0] + 1) + 1 / (
+        positions[-1] + 1), positions