Completion: dedicated completion header and basic filename completion

src/command_manager.cc

@@ -96,6 +96,13 @@ Completions CommandManager::complete(const std::string& command_line, size_t cur
 
         return result;
     }
+    if (token_to_complete == 1) // filename completion
+    {
+        Completions result(tokens[1].first, cursor_pos);
+        std::string prefix = command_line.substr(tokens[1].first, cursor_pos);
+        result.candidates = complete_filename(prefix);
+        return result;
+    }
     return Completions(cursor_pos, cursor_pos);
 }
 

src/command_manager.hh

@@ -7,7 +7,7 @@
 #include <functional>
 
 #include "exception.hh"
-
+#include "completion.hh"
 
 namespace Kakoune
 {
@@ -20,16 +20,6 @@ struct wrong_argument_count : runtime_error
 typedef std::vector<std::string> CommandParameters;
 typedef std::function<void (const CommandParameters&)> Command;
 
-struct Completions
-{
-    CommandParameters candidates;
-    size_t start;
-    size_t end;
-
-    Completions(size_t start, size_t end)
-        : start(start), end(end) {}
-};
-
 class CommandManager
 {
 public:

src/completion.cc

@@ -0,0 +1,34 @@
+#include "completion.hh"
+
+#include "utils.hh"
+
+#include <dirent.h>
+
+namespace Kakoune
+{
+
+CandidateList complete_filename(const std::string& prefix)
+{
+    size_t dir_end = prefix.find_last_of('/');
+    std::string dirname = "./";
+    std::string fileprefix = prefix;
+
+    if (dir_end != std::string::npos)
+    {
+        dirname = prefix.substr(0, dir_end + 1);
+        fileprefix = prefix.substr(dir_end + 1, std::string::npos);
+    }
+
+    auto dir = auto_raii(opendir(dirname.c_str()), closedir);
+
+    CandidateList result;
+    while (dirent* entry = readdir(dir))
+    {
+        std::string filename = entry->d_name;
+        if (filename.substr(0, fileprefix.length()) == fileprefix)
+            result.push_back(filename);
+    }
+    return result;
+}
+
+}

src/completion.hh

@@ -0,0 +1,25 @@
+#ifndef completion_hh_INCLUDED
+#define completion_hh_INCLUDED
+
+#include <string>
+#include <vector>
+
+namespace Kakoune
+{
+
+typedef std::vector<std::string> CandidateList;
+
+struct Completions
+{
+    CandidateList candidates;
+    size_t start;
+    size_t end;
+
+    Completions(size_t start, size_t end)
+        : start(start), end(end) {}
+};
+
+CandidateList complete_filename(const std::string& prefix);
+
+}
+#endif // completion_hh_INCLUDED