From e12bf4978c1c4bfe9e6b1d731cb835badf04255d Mon Sep 17 00:00:00 2001
From: Maxime Coste <frrrwww@gmail.com>
Date: Thu, 2 Jan 2014 19:20:16 +0000
Subject: [PATCH] Try prefix completion and then subsequence completion for
 option names

fixes #4
---
 src/option_manager.cc | 20 +++++++++++++++-----
 src/option_manager.hh |  3 +++
 2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/src/option_manager.cc b/src/option_manager.cc
index 4bb8d2da..58589624 100644
--- a/src/option_manager.cc
+++ b/src/option_manager.cc
@@ -63,25 +63,35 @@ const Option& OptionManager::operator[](const String& name) const
         throw option_not_found(name);
 }
 
-CandidateList OptionManager::complete_option_name(const String& prefix,
-                                                  ByteCount cursor_pos)
+template<typename MatchingFunc>
+CandidateList OptionManager::get_matching_names(MatchingFunc func)
 {
-    String real_prefix = prefix.substr(0, cursor_pos);
     CandidateList result;
     if (m_parent)
-        result = m_parent->complete_option_name(prefix, cursor_pos);
+        result = m_parent->get_matching_names(func);
     for (auto& option : m_options)
     {
         if (option->flags() & Option::Flags::Hidden)
             continue;
 
         const auto& name = option->name();
-        if (prefix_match(name, real_prefix) and not contains(result, name))
+        if (func(name) and not contains(result, name))
             result.push_back(name);
     }
     return result;
 }
 
+CandidateList OptionManager::complete_option_name(const String& prefix,
+                                                  ByteCount cursor_pos)
+{
+    using namespace std::placeholders;
+    String real_prefix = prefix.substr(0, cursor_pos);
+    auto result = get_matching_names(std::bind(prefix_match, _1, std::ref(real_prefix)));
+    if (result.empty())
+        result = get_matching_names(std::bind(subsequence_match, _1, std::ref(real_prefix)));
+    return result;
+}
+
 OptionManager::OptionList OptionManager::flatten_options() const
 {
     OptionList res = m_parent ? m_parent->flatten_options() : OptionList{};
diff --git a/src/option_manager.hh b/src/option_manager.hh
index a8688b27..ae73e4f8 100644
--- a/src/option_manager.hh
+++ b/src/option_manager.hh
@@ -91,6 +91,9 @@ private:
     // the only one allowed to construct a root option manager
     friend class GlobalOptions;
 
+    template<typename MatchingFunc>
+    CandidateList get_matching_names(MatchingFunc func);
+
     std::vector<std::unique_ptr<Option>> m_options;
     OptionManager* m_parent;