Boost C++ Libraries: Ticket #3265: parse vectors

cc set

Thu, 23 Jul 2009 06:19:04 GMT

cc dcnieho@… added

Full proposed patch, now including support for vectors of strings with proper double quote support.

Index: value_semantic.hpp
===================================================================
--- value_semantic.hpp  (revision 54915)
+++ value_semantic.hpp  (working copy)
@@ -8,6 +8,8 @@
 #include <boost/throw_exception.hpp>
+#include <boost/algorithm/string.hpp>
+
 namespace boost { namespace program_options {
     extern BOOST_PROGRAM_OPTIONS_DECL std::string arg;
@@ -124,7 +126,8 @@
 #endif
     /** Validates sequences. Allows multiple values per option occurrence
-       and multiple occurrences. */
+       and multiple occurrences. This function is only called when user
+       supplied vector<T> as datatype in option_description */
     template<class T, class charT>
     void validate(boost::any& v,
                   const std::vector<std::basic_string<charT> >& s,
@@ -142,11 +145,41 @@
                 /* We call validate so that if user provided
                    a validator for class T, we use it even
                    when parsing vector<T>.  */
-                boost::any a;
-                std::vector<std::basic_string<charT> > v;
-                v.push_back(s[i]);
-                validate(a, v, (T*)0, 0);
-                tv->push_back(boost::any_cast<T>(a));
+
+                vector<std::basic_string<charT>> value;
+
+                // test if vector notation is used in input
+                if (*s[i].begin() == '(' && *s[i].rbegin() == ')')
+                {
+                    // test if a vector of strings is requested
+                    if (is_same<T, string>::value||is_same<T, wstring>::value)
+                    {
+                        /** Strings needs special treatment, cant simply split
+                            on space character as that might be part of the
+                            string. Using split_winmain we can allow for the
+                            same grammar within the brackets () as for strings
+                            on the command line, that is, e.g., use "" to
+                            encapsulate strings with spaces. For complete
+                            grammar, see links in the split_winmain source. */
+                        value = split_winmain(s[i].substr(1, s[i].size()-2));
+                    }
+                    else
+                    {
+                        split( value, s[i].substr(1, s[i].size()-2), is_any_of(
" ") );
+                    }
+                }
+                else
+                    value.push_back(s[i]);
+
+                // validate option values
+                for (unsigned j = 0; j < value.size(); j++)
+                {
+                    boost::any a;
+                    std::vector<std::basic_string<charT> > v;
+                    v.push_back(value[j]);
+                    validate(a, v, (T*)0, 0);
+                    tv->push_back(boost::any_cast<T>(a));
+                }
             }
             catch(const bad_lexical_cast& /*e*/) {
                 boost::throw_exception(invalid_option_value(s[i]));}}}

Sascha Ochsenknecht — Tue, 08 Dec 2009 09:52:38 GMT

Here is the archived discussion on boost users list: boost user

Fri, 17 Jun 2011 05:26:24 GMT

Dear Volodya and/or Sascha,

I still have interest in this addition and am using code made possible by it daily, so far I haven't run into any problems. Could you consider looking at this and including it?

Thank you very much for your time, let me know if I can help in any way!

Best, Dee

Thu, 27 Dec 2012 10:21:09 GMT

Hmm, here is a slightly updated version of the patch. Some usage of std wasn't prefixed with std:: and the call to split should split on any whitespace (tabs are fine too after all) and have token compressing on in case e.g. multiple spaces delimit two entries.

Index: value_semantic.hpp
===================================================================
--- value_semantic.hpp  (revision 54915)
+++ value_semantic.hpp  (working copy)
@@ -8,6 +8,8 @@
 #include <boost/throw_exception.hpp>
+#include <boost/algorithm/string.hpp>
+
 namespace boost { namespace program_options {
     extern BOOST_PROGRAM_OPTIONS_DECL std::string arg;
@@ -124,7 +126,8 @@
 #endif
     /** Validates sequences. Allows multiple values per option occurrence
-       and multiple occurrences. */
+       and multiple occurrences. This function is only called when user
+       supplied vector<T> as datatype in option_description */
     template<class T, class charT>
     void validate(boost::any& v,
                   const std::vector<std::basic_string<charT> >& s,
@@ -142,11 +145,41 @@
                 /* We call validate so that if user provided
                    a validator for class T, we use it even
                    when parsing vector<T>.  */
-                boost::any a;
-                std::vector<std::basic_string<charT> > v;
-                v.push_back(s[i]);
-                validate(a, v, (T*)0, 0);
-                tv->push_back(boost::any_cast<T>(a));
+
+                std::vector<std::basic_string<charT>> value;
+
+                // test if vector notation is used in input
+                if (*s[i].begin() == '(' && *s[i].rbegin() == ')')
+                {
+                    // test if a vector of strings is requested
+                    if (is_same<T, std::string>::value||is_same<T, std::wstring>::value)
+                    {
+                        /** Strings needs special treatment, cant simply split
+                            on space character as that might be part of the
+                            string. Using split_winmain we can allow for the
+                            same grammar within the brackets () as for strings
+                            on the command line, that is, e.g., use "" to
+                            encapsulate strings with spaces. For complete
+                            grammar, see links in the split_winmain source. */
+                        value = split_winmain(s[i].substr(1, s[i].size()-2));
+                    }
+                    else
+                    {
+                        split( value, s[i].substr(1, s[i].size()-2), is_space(), token_compress_on );
+                    }
+                }
+                else
+                    value.push_back(s[i]);
+
+                // validate option values
+                for (unsigned j = 0; j < value.size(); j++)
+                {
+                    boost::any a;
+                    std::vector<std::basic_string<charT> > v;
+                    v.push_back(value[j]);
+                    validate(a, v, (T*)0, 0);
+                    tv->push_back(boost::any_cast<T>(a));
+                }
             }
             catch(const bad_lexical_cast& /*e*/) {
                 boost::throw_exception(invalid_option_value(s[i]));}}}

Best and thanks, Dee