From 777a79d37c675540052e0d4212800e877905e49e Mon Sep 17 00:00:00 2001
From: Maxime Coste <frrrwww@gmail.com>
Date: Wed, 12 Dec 2012 13:51:15 +0100
Subject: [PATCH] File completion: when no files match entered text as prefix,
 try as regex

---
 src/completion.cc | 46 ++++++++++++++++++++++++++++++++++------------
 1 file changed, 34 insertions(+), 12 deletions(-)

diff --git a/src/completion.cc b/src/completion.cc
index 7f9325fe..8ee18aa2 100644
--- a/src/completion.cc
+++ b/src/completion.cc
@@ -13,6 +13,20 @@
 namespace Kakoune
 {
 
+static boost::regex make_regex_ifp(const String& ex)
+{
+    boost::regex result;
+    if (not ex.empty())
+    {
+         try
+         {
+             result = boost::regex(ex.c_str());
+         }
+         catch(boost::regex_error&) {}
+    }
+    return result;
+}
+
 CandidateList complete_filename(const Context& context,
                                 const String& prefix,
                                 ByteCount cursor_pos)
@@ -22,10 +36,7 @@ CandidateList complete_filename(const Context& context,
     String dirprefix;
     String fileprefix = real_prefix;
 
-    String ignored_files = context.options()["ignored_files"].as_string();
-    boost::regex ignored_files_regex;
-    if (not ignored_files.empty())
-         ignored_files_regex = boost::regex(ignored_files.c_str());
+    boost::regex ignored_files = make_regex_ifp(context.options()["ignored_files"].as_string());
 
     ByteCount dir_end = -1;
     for (ByteCount i = 0; i < real_prefix.length(); ++i)
@@ -41,36 +52,47 @@ CandidateList complete_filename(const Context& context,
     }
 
     DIR* dir = opendir(dirname.c_str());
-    auto closeDir = on_scope_end([=](){ closedir(dir); });
+    auto closeDir = on_scope_end([=]{ closedir(dir); });
 
     CandidateList result;
     if (not dir)
         return result;
 
     const bool check_ignored_files = not ignored_files.empty() and
-        not boost::regex_match(fileprefix.c_str(), ignored_files_regex);
+        not boost::regex_match(fileprefix.c_str(), ignored_files);
 
+    boost::regex file_regex = make_regex_ifp(fileprefix);
+    CandidateList regex_result;
     while (dirent* entry = readdir(dir))
     {
         String filename = entry->d_name;
         if (filename.empty())
             continue;
 
-        if (check_ignored_files and
-            boost::regex_match(filename.c_str(), ignored_files_regex))
+        if (check_ignored_files and boost::regex_match(filename.c_str(), ignored_files))
             continue;
 
-        if (filename.substr(0, fileprefix.length()) == fileprefix)
+        const bool match_prefix = (filename.substr(0, fileprefix.length()) == fileprefix);
+        const bool match_regex  = not file_regex.empty() and
+            boost::regex_match(filename.c_str(), file_regex);
+
+        if (match_prefix or match_regex)
         {
             String name = dirprefix + filename;
             if (entry->d_type == DT_DIR)
                 name += '/';
             if (fileprefix.length() != 0 or filename[0] != '.')
-                result.push_back(escape(name));
+            {
+                if (match_prefix)
+                    result.push_back(escape(name));
+                if (match_regex)
+                    regex_result.push_back(escape(name));
+            }
         }
     }
-    std::sort(result.begin(), result.end());
-    return result;
+    CandidateList& real_result = result.empty() ? regex_result : result;
+    std::sort(real_result.begin(), real_result.end());
+    return real_result;
 }
 
 }