[sbuild::util] Add split_string_strict

split_string splits a string into chunks separated by the
specified separator.  split_string_strict doesn't eliminate
empty strings when the separator appears at the string start
or end, or if multiple separators are joined together.

2 files changed, 88 insertions, 2 deletions

diff --git a/sbuild/sbuild-util.cc b/sbuild/sbuild-util.cc
index b9403aa0..dc9e7a23 100644
--- a/sbuild/sbuild-util.cc
+++ b/sbuild/sbuild-util.cc
@@ -235,7 +235,13 @@ sbuild::split_string (std::string const& value,
   while (pos !=std::string::npos || last_pos != std::string::npos)
     {
       // Add to list
-      ret.push_back(value.substr(last_pos, pos - last_pos));
+      if (pos == std::string::npos)
+	// Entire string from last_pos
+	ret.push_back(value.substr(last_pos, pos));
+      else
+	// Between pos and last_pos
+	ret.push_back(value.substr(last_pos, pos - last_pos));
+
       // Find next
       last_pos = value.find_first_not_of(separator, pos);
       pos = value.find_first_of(separator, last_pos);
@@ -244,6 +250,34 @@ sbuild::split_string (std::string const& value,
   return ret;
 }
 
+string_list
+sbuild::split_string_strict (std::string const& value,
+			     std::string const& separator)
+{
+  string_list ret;
+
+  std::string::size_type last_pos = 0;
+  // Find first separator.
+  std::string::size_type pos = value.find_first_of(separator, last_pos);
+
+  while (pos !=std::string::npos)
+    {
+      // Add to list
+      if (pos == std::string::npos)
+	// Entire string from last_pos
+	ret.push_back(value.substr(last_pos, pos));
+      else
+	// Between pos and last_pos
+	ret.push_back(value.substr(last_pos, pos - last_pos));
+
+      // Find next
+      last_pos = pos + separator.length();
+      pos = value.find_first_of(separator, last_pos);
+    }
+
+  return ret;
+}
+
 std::wstring
 sbuild::widen_string (std::string const& str,
 		      std::locale        locale)
diff --git a/sbuild/sbuild-util.h b/sbuild/sbuild-util.h
index 9597b9e3..0b612ed8 100644
--- a/sbuild/sbuild-util.h
+++ b/sbuild/sbuild-util.h
@@ -115,7 +115,10 @@ namespace sbuild
 
   /**
    * Split a string into a string_list.  The string is split using
-   * separator as a delimiter.
+   * separator as a delimiter.  Note that only non-zero-length strings
+   * are preserved, so multiple concatenated delimiters or delimiters
+   * at the beginning and end of the string will not result in empty
+   * strings in the list.
    *
    * @param value the string to split.
    * @param separator the delimiting character or characters.
@@ -155,6 +158,55 @@ namespace sbuild
 		std::string const& separator);
 
   /**
+   * Split a string into a string_list.  The string is split using
+   * separator as a delimiter.  All delimiters are used as string
+   * separators, so delimiters at the beginning or end of a string, or
+   * which are concatenated together, will result in empty strings in
+   * the string list.
+   *
+   * @param value the string to split.
+   * @param separator the delimiting character or characters.
+   * @returns a string_list.
+   *
+   * @todo Provide an alternative that splits the string in place
+   * using an iterator interface.
+   */
+  template <typename S>
+  std::vector<S>
+  split_string_strict (S const& value,
+		       S const& separator)
+  {
+    std::vector<S> ret;
+
+    // Skip any separators at the start
+    typename S::size_type last_pos = 0;
+    // Find first separator.
+    typename S::size_type pos = value.find_first_of(separator, last_pos);
+
+    while (pos !=S::npos || last_pos != S::npos)
+      {
+	// Add to list
+	if (pos == std::string::npos)
+	  // Entire string from last_pos
+	  ret.push_back(value.substr(last_pos, pos));
+	else
+	  // Between pos and last_pos
+	  ret.push_back(value.substr(last_pos, pos - last_pos));
+
+	// Find next
+	last_pos = pos + separator.length();
+	pos = value.find_first_of(separator, last_pos);
+      }
+
+    return ret;
+  }
+
+  // template
+  std::vector<std::string>
+  split_string_strict (std::string const& value,
+		       std::string const& separator);
+
+  /**
    * Widen a string.  The narrow string is converted into a wide
    * string.  Note that any conversion error will cause the string to
    * be clipped at the point of error.