From 89bc63fb386f0e4d6e2b21c0d806da1e8de0a34d Mon Sep 17 00:00:00 2001
From: Boris Kolpackov <boris@codesynthesis.com>
Date: Fri, 19 Jan 2018 09:05:51 +0200
Subject: Add path::make_{directory,leaf,base}()

---
 libbutl/path.ixx | 73 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 libbutl/path.mxx | 24 +++++++++++++++++--
 2 files changed, 95 insertions(+), 2 deletions(-)

diff --git a/libbutl/path.ixx b/libbutl/path.ixx
index f86a57e..b754bed 100644
--- a/libbutl/path.ixx
+++ b/libbutl/path.ixx
@@ -150,6 +150,10 @@ LIBBUTL_MODEXPORT namespace butl //@@ MOD Clang needs this for some reason.
   inline basic_path<C, K> basic_path<C, K>::
   leaf () const
   {
+    // While it would have been simpler to implement this one in term of
+    // make_leaf(), this implementation is potentially more efficient
+    // (think of the small string optimization).
+    //
     const string_type& s (this->path_);
     size_type n (_size ());
 
@@ -163,9 +167,37 @@ LIBBUTL_MODEXPORT namespace butl //@@ MOD Clang needs this for some reason.
   }
 
   template <typename C, typename K>
+  inline basic_path<C, K>& basic_path<C, K>::
+  make_leaf ()
+  {
+    string_type& s (this->path_);
+    size_type n (_size ());
+
+    size_type p (n != 0
+                 ? traits::rfind_separator (s, n - 1)
+                 : string_type::npos);
+
+    if (p != string_type::npos)
+    {
+      s.erase (0, p + 1);
+
+      // Keep the original tsep unless the path became empty.
+      //
+      if (s.empty ())
+        this->tsep_ = 0;
+    }
+
+    return *this;
+  }
+
+  template <typename C, typename K>
   inline typename basic_path<C, K>::dir_type basic_path<C, K>::
   directory () const
   {
+    // While it would have been simpler to implement this one in term of
+    // make_directory(), this implementation is potentially more efficient
+    // (think of the small string optimization).
+    //
     const string_type& s (this->path_);
     size_type n (_size ());
 
@@ -179,6 +211,23 @@ LIBBUTL_MODEXPORT namespace butl //@@ MOD Clang needs this for some reason.
   }
 
   template <typename C, typename K>
+  inline basic_path<C, K>& basic_path<C, K>::
+  make_directory ()
+  {
+    string_type& s (this->path_);
+    size_type n (_size ());
+
+    size_type p (n != 0
+                 ? traits::rfind_separator (s, n - 1)
+                 : string_type::npos);
+
+    s.resize (p != string_type::npos ? p + 1 : 0); // Include trailing slash.
+    _init ();
+
+    return *this;
+  }
+
+  template <typename C, typename K>
   inline auto basic_path<C, K>::
   begin () const -> iterator
   {
@@ -279,6 +328,10 @@ LIBBUTL_MODEXPORT namespace butl //@@ MOD Clang needs this for some reason.
   inline basic_path<C, K> basic_path<C, K>::
   base () const
   {
+    // While it would have been simpler to implement this one in term of
+    // make_base(), this implementation is potentially more efficient (think
+    // of the small string optimization).
+    //
     const string_type& s (this->path_);
     size_type p (traits::find_extension (s));
 
@@ -288,6 +341,26 @@ LIBBUTL_MODEXPORT namespace butl //@@ MOD Clang needs this for some reason.
   }
 
   template <typename C, typename K>
+  inline basic_path<C, K>& basic_path<C, K>::
+  make_base ()
+  {
+    string_type& s (this->path_);
+    size_type p (traits::find_extension (s));
+
+    if (p != string_type::npos)
+    {
+      s.resize (0, p);
+
+      // Keep the original tsep unless the path became empty.
+      //
+      if (s.empty ())
+        this->tsep_ = 0;
+    }
+
+    return *this;
+  }
+
+  template <typename C, typename K>
   inline typename basic_path<C, K>::string_type basic_path<C, K>::
   extension () const
   {
diff --git a/libbutl/path.mxx b/libbutl/path.mxx
index 520453a..01fa0fc 100644
--- a/libbutl/path.mxx
+++ b/libbutl/path.mxx
@@ -510,14 +510,18 @@ LIBBUTL_MODEXPORT namespace butl
 
     // Constructors.
     //
-    path_data (): tsep_ (0) {}
+    path_data ()
+        : tsep_ (0) {}
 
     path_data (string_type&& p, difference_type ts)
         : path_ (std::move (p)), tsep_ (path_.empty () ? 0 : ts) {}
 
     explicit
     path_data (string_type&& p)
-        : path_ (std::move (p)), tsep_ (0)
+        : path_ (std::move (p)) { _init (); }
+
+    void
+    _init ()
     {
       size_type n (path_.size ()), i;
 
@@ -531,6 +535,8 @@ LIBBUTL_MODEXPORT namespace butl
           path_.pop_back ();
         }
       }
+      else
+        tsep_ = 0;
     }
   };
 
@@ -764,6 +770,11 @@ LIBBUTL_MODEXPORT namespace butl
     basic_path
     leaf () const;
 
+    // As above but make the instance itself the leaf. Return *this.
+    //
+    basic_path&
+    make_leaf ();
+
     // Return the path without the specified directory part. Throws
     // invalid_path if the directory is not a prefix of *this. Expects both
     // paths to be normalized.
@@ -777,6 +788,11 @@ LIBBUTL_MODEXPORT namespace butl
     dir_type
     directory () const;
 
+    // As above but make the instance itself the directory. Return *this.
+    //
+    basic_path&
+    make_directory ();
+
     // Return the directory part of the path without the specified leaf part.
     // Throws invalid_path if the leaf is not a suffix of *this. Expects both
     // paths to be normalized.
@@ -795,6 +811,9 @@ LIBBUTL_MODEXPORT namespace butl
     basic_path
     base () const;
 
+    basic_path&
+    make_base ();
+
     // Return the extension or empty string if not present. If not empty, then
     // the result starts with the character past the dot.
     //
@@ -1081,6 +1100,7 @@ LIBBUTL_MODEXPORT namespace butl
     basic_path (data_type&& d): base_type (std::move (d)) {}
 
     using base_type::_size;
+    using base_type::_init;
 
     // Common implementation for operator/= and operator+=.
     //
-- 
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