1 files changed, 144 insertions, 0 deletions
diff --git a/include/jsoncons/text_source_adaptor.hpp b/include/jsoncons/text_source_adaptor.hpp
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+++ b/include/jsoncons/text_source_adaptor.hpp
@@ -0,0 +1,144 @@
+// Copyright 2021 Daniel Parker
+// Distributed under the Boost license, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+
+// See https://github.com/danielaparker/jsoncons for latest version
+
+#ifndef JSONCONS_TEXT_SOURCE_ADAPTOR_HPP
+#define JSONCONS_TEXT_SOURCE_ADAPTOR_HPP
+
+#include <cstddef>
+#include <string>
+#include <vector>
+#include <stdexcept>
+#include <system_error>
+#include <memory> // std::allocator_traits
+#include <vector> // std::vector
+#include <jsoncons/unicode_traits.hpp>
+#include <jsoncons/json_error.hpp> // json_errc
+#include <jsoncons/source.hpp>
+#include <jsoncons/json_exception.hpp>
+
+namespace jsoncons {
+
+    // unicode_source_adaptor
+
+    template<class Source,class Allocator>
+    class unicode_source_adaptor 
+    {
+    public:
+        using value_type = typename Source::value_type;
+        using source_type = Source;
+    private:
+        source_type source_;
+        bool bof_;
+
+
+    public:
+        template <class Sourceable>
+        unicode_source_adaptor(Sourceable&& source)
+            : source_(std::forward<Sourceable>(source)),
+              bof_(true)
+        {
+        }
+
+        bool is_error() const
+        {
+            return source_.is_error();  
+        }
+
+        bool eof() const
+        {
+            return source_.eof();  
+        }
+
+        span<const value_type> read_buffer(std::error_code& ec)
+        {
+            if (source_.eof())
+            {
+                return span<const value_type>();
+            }
+
+            auto s = source_.read_buffer();
+            const value_type* data = s.data();
+            std::size_t length = s.size();
+
+            if (bof_ && length > 0)
+            {
+                auto r = unicode_traits::detect_encoding_from_bom(data, length);
+                if (!(r.encoding == unicode_traits::encoding_kind::utf8 || r.encoding == unicode_traits::encoding_kind::undetected))
+                {
+                    ec = json_errc::illegal_unicode_character;
+                    return;
+                }
+                length -= (r.ptr - data);
+                data = r.ptr;
+                bof_ = false;
+            }
+            return span<const value_type>(data, length);            
+        }
+    };
+
+    // json_source_adaptor
+
+    template<class Source,class Allocator>
+    class json_source_adaptor 
+    {
+    public:
+        using value_type = typename Source::value_type;
+        using value_type = typename Source::value_type;
+        using source_type = Source;
+    private:
+        source_type source_;
+        bool bof_;
+
+    public:
+
+        template <class Sourceable>
+        json_source_adaptor(Sourceable&& source)
+            : source_(std::forward<Sourceable>(source)),
+              bof_(true)
+        {
+        }
+
+        bool is_error() const
+        {
+            return source_.is_error();  
+        }
+
+        bool eof() const
+        {
+            return source_.eof();  
+        }
+
+        span<const value_type> read_buffer(std::error_code& ec)
+        {
+            if (source_.eof())
+            {
+                return span<const value_type>();
+            }
+
+            auto s = source_.read_buffer();
+            const value_type* data = s.data(); 
+            std::size_t length = s.size();
+
+            if (bof_ && length > 0)
+            {
+                auto r = unicode_traits::detect_json_encoding(data, length);
+                if (!(r.encoding == unicode_traits::encoding_kind::utf8 || r.encoding == unicode_traits::encoding_kind::undetected))
+                {
+                    ec = json_errc::illegal_unicode_character;
+                    return span<const value_type>();
+                }
+                length -= (r.ptr - data);
+                data = r.ptr;
+                bof_ = false;
+            }
+            return span<const value_type>(data, length);            
+        }
+    };
+
+} // namespace jsoncons
+
+#endif
+