From 18e4be616c8edefd975af524a72923c7183a0197 Mon Sep 17 00:00:00 2001
From: Fangrui Song <i@maskray.me>
Date: Thu, 20 Dec 2018 00:00:42 -0800
Subject: [PATCH] Add `strict` to FuzzyMatcher::Match

In completion, underscore prefixed builtin macros may be annoying when the first type character is not an underscore.

When `strict` is true, `Match` enforces the first characters should be loosely of the same category.
---
 src/fuzzy_match.cc                      | 6 +++++-
 src/fuzzy_match.hh                      | 2 +-
 src/messages/textDocument_completion.cc | 2 +-
 src/messages/workspace.cc               | 4 ++--
 4 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/src/fuzzy_match.cc b/src/fuzzy_match.cc
index 680aa4ac..7f70b168 100644
--- a/src/fuzzy_match.cc
+++ b/src/fuzzy_match.cc
@@ -107,7 +107,9 @@ FuzzyMatcher::FuzzyMatcher(std::string_view pattern, int sensitivity) {
     }
 }
 
-int FuzzyMatcher::Match(std::string_view text) {
+int FuzzyMatcher::Match(std::string_view text, bool strict) {
+  if (pat.empty() != text.empty())
+    return kMinScore;
   int n = int(text.size());
   if (n > kMaxText)
     return kMinScore + 1;
@@ -115,6 +117,8 @@ int FuzzyMatcher::Match(std::string_view text) {
   for (int i = 0; i < n; i++)
     low_text[i] = ::tolower(text[i]);
   CalculateRoles(text, text_role, &text_set);
+  if (strict && n && !!pat_role[0] != !!text_role[0])
+    return kMinScore;
   dp[0][0][0] = dp[0][0][1] = 0;
   for (int j = 0; j < n; j++) {
     dp[0][j + 1][0] = dp[0][j][0] + MissScore(j, false);
diff --git a/src/fuzzy_match.hh b/src/fuzzy_match.hh
index 9153c6c0..a7a98a9e 100644
--- a/src/fuzzy_match.hh
+++ b/src/fuzzy_match.hh
@@ -29,7 +29,7 @@ public:
   constexpr static int kMinScore = INT_MIN / 4;
 
   FuzzyMatcher(std::string_view pattern, int case_sensitivity);
-  int Match(std::string_view text);
+  int Match(std::string_view text, bool strict);
 
 private:
   int case_sensitivity;
diff --git a/src/messages/textDocument_completion.cc b/src/messages/textDocument_completion.cc
index 3eb76b3a..be84bad7 100644
--- a/src/messages/textDocument_completion.cc
+++ b/src/messages/textDocument_completion.cc
@@ -175,7 +175,7 @@ void FilterCandidates(CompletionList &result, const std::string &complete_text,
       const std::string &filter =
           item.filterText.size() ? item.filterText : item.label;
       item.score_ = ReverseSubseqMatch(complete_text, filter, sensitive) >= 0
-                        ? fuzzy.Match(filter)
+                        ? fuzzy.Match(filter, true)
                         : FuzzyMatcher::kMinScore;
     }
     items.erase(std::remove_if(items.begin(), items.end(),
diff --git a/src/messages/workspace.cc b/src/messages/workspace.cc
index 5661a5d6..5b049958 100644
--- a/src/messages/workspace.cc
+++ b/src/messages/workspace.cc
@@ -180,8 +180,8 @@ done_add:
           longest, int(db->GetSymbolName(std::get<2>(cand), true).size()));
     FuzzyMatcher fuzzy(query, g_config->workspaceSymbol.caseSensitivity);
     for (auto &cand : cands)
-      std::get<1>(cand) =
-          fuzzy.Match(db->GetSymbolName(std::get<2>(cand), std::get<1>(cand)));
+      std::get<1>(cand) = fuzzy.Match(
+          db->GetSymbolName(std::get<2>(cand), std::get<1>(cand)), false);
     std::sort(cands.begin(), cands.end(), [](const auto &l, const auto &r) {
       return std::get<1>(l) > std::get<1>(r);
     });