GH-1047 parse world files and integrate MCEdit with world page

depends/libnbtplusplus/src/text/json_formatter.cpp

@@ -0,0 +1,195 @@
+/*
+ * libnbt++ - A library for the Minecraft Named Binary Tag format.
+ * Copyright (C) 2013, 2015  ljfa-ag
+ *
+ * This file is part of libnbt++.
+ *
+ * libnbt++ is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * libnbt++ is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with libnbt++.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include "text/json_formatter.h"
+#include "nbt_tags.h"
+#include "nbt_visitor.h"
+#include <cmath>
+#include <iomanip>
+#include <limits>
+
+namespace nbt
+{
+namespace text
+{
+
+namespace //anonymous
+{
+    ///Helper class which uses the Visitor pattern to pretty-print tags
+    class json_fmt_visitor : public const_nbt_visitor
+    {
+    public:
+        json_fmt_visitor(std::ostream& os, const json_formatter& fmt):
+            os(os)
+        {}
+
+        void visit(const tag_byte& b) override
+        { os << static_cast<int>(b.get()) << "b"; } //We don't want to print a character
+
+        void visit(const tag_short& s) override
+        { os << s.get() << "s"; }
+
+        void visit(const tag_int& i) override
+        { os << i.get(); }
+
+        void visit(const tag_long& l) override
+        { os << l.get() << "l"; }
+
+        void visit(const tag_float& f) override
+        {
+            write_float(f.get());
+            os << "f";
+        }
+
+        void visit(const tag_double& d) override
+        {
+            write_float(d.get());
+            os << "d";
+        }
+
+        void visit(const tag_byte_array& ba) override
+        { os << "[" << ba.size() << " bytes]"; }
+
+        void visit(const tag_string& s) override
+        { os << '"' << s.get() << '"'; } //TODO: escape special characters
+
+        void visit(const tag_list& l) override
+        {
+            //Wrap lines for lists of lists or compounds.
+            //Lists of other types can usually be on one line without problem.
+            const bool break_lines = l.size() > 0 &&
+                (l.el_type() == tag_type::List || l.el_type() == tag_type::Compound);
+
+            os << "[";
+            if(break_lines)
+            {
+                os << "\n";
+                ++indent_lvl;
+                for(unsigned int i = 0; i < l.size(); ++i)
+                {
+                    indent();
+                    if(l[i])
+                        l[i].get().accept(*this);
+                    else
+                        write_null();
+                    if(i != l.size()-1)
+                        os << ",";
+                    os << "\n";
+                }
+                --indent_lvl;
+                indent();
+            }
+            else
+            {
+                for(unsigned int i = 0; i < l.size(); ++i)
+                {
+                    if(l[i])
+                        l[i].get().accept(*this);
+                    else
+                        write_null();
+                    if(i != l.size()-1)
+                        os << ", ";
+                }
+            }
+            os << "]";
+        }
+
+        void visit(const tag_compound& c) override
+        {
+            if(c.size() == 0) //No line breaks inside empty compounds please
+            {
+                os << "{}";
+                return;
+            }
+
+            os << "{\n";
+            ++indent_lvl;
+            unsigned int i = 0;
+            for(const auto& kv: c)
+            {
+                indent();
+                os << kv.first << ": ";
+                if(kv.second)
+                    kv.second.get().accept(*this);
+                else
+                    write_null();
+                if(i != c.size()-1)
+                    os << ",";
+                os << "\n";
+                ++i;
+            }
+            --indent_lvl;
+            indent();
+            os << "}";
+        }
+
+        void visit(const tag_int_array& ia) override
+        {
+            os << "[";
+            for(unsigned int i = 0; i < ia.size(); ++i)
+            {
+                os << ia[i];
+                if(i != ia.size()-1)
+                    os << ", ";
+            }
+            os << "]";
+        }
+
+    private:
+        const std::string indent_str = "  ";
+
+        std::ostream& os;
+        int indent_lvl = 0;
+
+        void indent()
+        {
+            for(int i = 0; i < indent_lvl; ++i)
+                os << indent_str;
+        }
+
+        template<class T>
+        void write_float(T val, int precision = std::numeric_limits<T>::max_digits10)
+        {
+            if(std::isfinite(val))
+                os << std::setprecision(precision) << val;
+            else if(std::isinf(val))
+            {
+                if(std::signbit(val))
+                    os << "-";
+                os << "Infinity";
+            }
+            else
+                os << "NaN";
+        }
+
+        void write_null()
+        {
+            os << "null";
+        }
+    };
+}
+
+void json_formatter::print(std::ostream& os, const tag& t) const
+{
+    json_fmt_visitor v(os, *this);
+    t.accept(v);
+}
+
+}
+}