Add a split function that does not take an escape and returns StringViews

When an escape character is not present, split can just return sub
strings of the parameter, so we can avoid duplicating the original
string data.

src/commands.cc

@@ -691,7 +691,7 @@ void define_command(const ParametersParser& parser, Context& context)
                 { "pos_in_token",      to_string(pos_in_token) }
             };
             String output = ShellManager::instance().eval(shell_cmd, context, params, vars);
-            return Completions{ 0_byte, params[token_to_complete].length(), split(output, '\n') };
+            return Completions{ 0_byte, params[token_to_complete].length(), split(output, '\n', 0) };
         };
     }
 

src/file.cc

@@ -350,7 +350,7 @@ std::vector<String> complete_command(StringView prefix, ByteCount cursor_pos)
     };
     static std::unordered_map<String, CommandCache> command_cache;
 
-    std::vector<String> path;
+    std::vector<StringView> path;
     if (dir_end != -1)
     {
         path.emplace_back(real_prefix.substr(0, dir_end + 1));
@@ -360,8 +360,9 @@ std::vector<String> complete_command(StringView prefix, ByteCount cursor_pos)
         path = split(getenv("PATH"), ':');
 
     std::vector<String> res;
-    for (auto dirname : path)
+    for (auto dir : path)
     {
+        String dirname = dir;
         if (not dirname.empty() and dirname.back() != '/')
             dirname += '/';
 

src/string.cc

@@ -46,6 +46,22 @@ std::vector<String> split(StringView str, char separator, char escape)
     return res;
 }
 
+std::vector<StringView> split(StringView str, char separator)
+{
+    std::vector<StringView> res;
+    auto beg = str.begin();
+    for (auto it = beg; it != str.end(); ++it)
+    {
+        if (*it == separator)
+        {
+            res.emplace_back(beg, it);
+            beg = it + 1;
+        }
+    }
+    res.emplace_back(beg, str.end());
+    return res;
+}
+
 String escape(StringView str, char character, char escape)
 {
     String res;

src/string.hh

@@ -271,7 +271,9 @@ inline String operator+(StringView lhs, StringView rhs)
     return res;
 }
 
-std::vector<String> split(StringView str, char separator, char escape = 0);
+std::vector<String> split(StringView str, char separator, char escape);
+std::vector<StringView> split(StringView str, char separator);
+
 String escape(StringView str, char character, char escape);
 String escape(StringView str, StringView characters, char escape);
 

src/unit_tests.cc

@@ -113,6 +113,15 @@ void test_string()
     kak_assert(splited[3] == "tchou:kanaky");
     kak_assert(splited[4] == "hihi:");
 
+    std::vector<StringView> splitedview = split("youpi:matin::tchou\\:kanaky:hihi\\:", ':');
+    kak_assert(splitedview[0] == "youpi");
+    kak_assert(splitedview[1] == "matin");
+    kak_assert(splitedview[2] == "");
+    kak_assert(splitedview[3] == "tchou\\");
+    kak_assert(splitedview[4] == "kanaky");
+    kak_assert(splitedview[5] == "hihi\\");
+    kak_assert(splitedview[6] == "");
+
     String escaped = escape("youpi:matin:tchou:", ':', '\\');
     kak_assert(escaped == "youpi\\:matin\\:tchou\\:");