From 43fabf618f644c1888cda51dc8dc905f6209f833 Mon Sep 17 00:00:00 2001
From: Peter Conrad <cyrano@quisquis.de>
Date: Mon, 5 Mar 2018 22:36:01 +0100
Subject: [PATCH] Code deduplication

---
 include/fc/io/json_relaxed.hpp | 76 ++--------------------------------
 src/io/json.cpp                | 27 +++++++++---
 2 files changed, 24 insertions(+), 79 deletions(-)

diff --git a/include/fc/io/json_relaxed.hpp b/include/fc/io/json_relaxed.hpp
index e4876f2..26a89a5 100644
--- a/include/fc/io/json_relaxed.hpp
+++ b/include/fc/io/json_relaxed.hpp
@@ -564,84 +564,14 @@ namespace fc { namespace json_relaxed
    template<typename T, bool strict>
    variant_object objectFromStream( T& in )
    {
-      mutable_variant_object obj;
-      try
-      {
-         char c = in.peek();
-         if( c != '{' )
-            FC_THROW_EXCEPTION( parse_error_exception,
-                                     "Expected '{', but read '${char}'",
-                                     ("char",string(&c, &c + 1)) );
-         in.get();
-         skip_white_space(in);
-         while( in.peek() != '}' )
-         {
-            if( in.peek() == ',' )
-            {
-               in.get();
-               continue;
-            }
-            if( skip_white_space(in) ) continue;
-            string key = json_relaxed::stringFromStream<T, strict>( in );
-            skip_white_space(in);
-            if( in.peek() != ':' )
-            {
-               FC_THROW_EXCEPTION( parse_error_exception, "Expected ':' after key \"${key}\"",
-                                        ("key", key) );
-            }
-            in.get();
-            auto val = json_relaxed::variant_from_stream<T, strict>( in );
-
-            obj(std::move(key),std::move(val));
-            skip_white_space(in);
-         }
-         if( in.peek() == '}' )
-         {
-            in.get();
-            return obj;
-         }
-         FC_THROW_EXCEPTION( parse_error_exception, "Expected '}' after ${variant}", ("variant", obj ) );
-      }
-      catch( const fc::eof_exception& e )
-      {
-         FC_THROW_EXCEPTION( parse_error_exception, "Unexpected EOF: ${e}", ("e", e.to_detail_string() ) );
-      }
-      catch( const std::ios_base::failure& e )
-      {
-         FC_THROW_EXCEPTION( parse_error_exception, "Unexpected EOF: ${e}", ("e", e.what() ) );
-      } FC_RETHROW_EXCEPTIONS( warn, "Error parsing object" );
+      return objectFromStreamBase<T>( in, []( T& in ){ return json_relaxed::stringFromStream<T, strict>( in ); },
+                                      []( T& in ){ return json_relaxed::variant_from_stream<T, strict>( in ); } );
    }
 
    template<typename T, bool strict>
    variants arrayFromStream( T& in )
    {
-      variants ar;
-      try
-      {
-        if( in.peek() != '[' )
-           FC_THROW_EXCEPTION( parse_error_exception, "Expected '['" );
-        in.get();
-        skip_white_space(in);
-
-        while( in.peek() != ']' )
-        {
-           if( in.peek() == ',' )
-           {
-              in.get();
-              continue;
-           }
-           if( skip_white_space(in) ) continue;
-           ar.push_back( json_relaxed::variant_from_stream<T, strict>(in) );
-           skip_white_space(in);
-        }
-        if( in.peek() != ']' )
-           FC_THROW_EXCEPTION( parse_error_exception, "Expected ']' after parsing ${variant}",
-                                    ("variant", ar) );
-
-        in.get();
-      } FC_RETHROW_EXCEPTIONS( warn, "Attempting to parse array ${array}",
-                                         ("array", ar ) );
-      return ar;
+       return arrayFromStreamBase<T>( in, []( T& in ){ return json_relaxed::variant_from_stream<T, strict>( in ); } );
    }
 
    template<typename T, bool strict>
diff --git a/src/io/json.cpp b/src/io/json.cpp
index 99feab9..8f4f2c1 100644
--- a/src/io/json.cpp
+++ b/src/io/json.cpp
@@ -19,7 +19,9 @@ namespace fc
     template<typename T> fc::string stringFromStream( T& in );
     template<typename T> bool skip_white_space( T& in );
     template<typename T> fc::string stringFromToken( T& in );
+    template<typename T> variant_object objectFromStreamBase( T& in, std::function<std::string(T&)>& get_key, std::function<variant(T&)>& get_value );
     template<typename T, json::parse_type parser_type> variant_object objectFromStream( T& in );
+    template<typename T> variants arrayFromStreamBase( T& in, std::function<variant(T&)>& get_value );
     template<typename T, json::parse_type parser_type> variants arrayFromStream( T& in );
     template<typename T, json::parse_type parser_type> variant number_from_stream( T& in );
     template<typename T> variant token_from_stream( T& in );
@@ -166,8 +168,8 @@ namespace fc
                                           ("token", token.str() ) );
    }
 
-   template<typename T, json::parse_type parser_type>
-   variant_object objectFromStream( T& in )
+   template<typename T>
+   variant_object objectFromStreamBase( T& in, std::string (*get_key)(T&), variant (*get_value)(T&) )
    {
       mutable_variant_object obj;
       try
@@ -186,7 +188,7 @@ namespace fc
                continue;
             }
             if( skip_white_space(in) ) continue;
-            string key = stringFromStream( in );
+            string key = get_key( in );
             skip_white_space(in);
             if( in.peek() != ':' )
             {
@@ -194,7 +196,7 @@ namespace fc
                                         ("key", key) );
             }
             in.get();
-            auto val = variant_from_stream<T, parser_type>( in );
+            auto val = get_value( in );
 
             obj(std::move(key),std::move(val));
          }
@@ -216,7 +218,14 @@ namespace fc
    }
 
    template<typename T, json::parse_type parser_type>
-   variants arrayFromStream( T& in )
+   variant_object objectFromStream( T& in )
+   {
+      return objectFromStreamBase<T>( in, []( T& in ){ return stringFromStream( in ); },
+                                      []( T& in ){ return variant_from_stream<T, parser_type>( in ); } );
+   }
+
+   template<typename T>
+   variants arrayFromStreamBase( T& in, variant (*get_value)(T&)  )
    {
       variants ar;
       try
@@ -233,7 +242,7 @@ namespace fc
               continue;
            }
            if( skip_white_space(in) ) continue;
-           ar.push_back( variant_from_stream<T, parser_type>(in) );
+           ar.push_back( get_value(in) );
         }
         if( in.peek() != ']' )
            FC_THROW_EXCEPTION( parse_error_exception, "Expected ']' after parsing ${variant}",
@@ -245,6 +254,12 @@ namespace fc
       return ar;
    }
 
+   template<typename T, json::parse_type parser_type>
+   variants arrayFromStream( T& in )
+   {
+       return arrayFromStreamBase<T>( in, []( T& in ){ return variant_from_stream<T, parser_type>( in ); } );
+   }
+
    template<typename T, json::parse_type parser_type>
    variant number_from_stream( T& in )
    {