Extracted StringReader and StringWriter from JsonParser

Split `Internals/` folder into `Data/`, `Deserialization/`, `Serialization/`

include/ArduinoJson/Serialization/JsonWriter.hpp

@@ -0,0 +1,184 @@
+// Copyright Benoit Blanchon 2014-2016
+// MIT License
+//
+// Arduino JSON library
+// https://github.com/bblanchon/ArduinoJson
+// If you like this project, please add a star!
+
+#pragma once
+
+#include "../Data/Encoding.hpp"
+#include "../Data/JsonFloat.hpp"
+#include "../Data/JsonInteger.hpp"
+#include "../Polyfills/attributes.hpp"
+#include "../Polyfills/math.hpp"
+#include "../Polyfills/normalize.hpp"
+#include "../Print.hpp"
+
+namespace ArduinoJson {
+namespace Internals {
+
+// Writes the JSON tokens to a Print implementation
+// This class is used by:
+// - JsonArray::writeTo()
+// - JsonObject::writeTo()
+// - JsonVariant::writeTo()
+// Its derived by PrettyJsonWriter that overrides some members to add
+// indentation.
+class JsonWriter {
+ public:
+  explicit JsonWriter(Print &sink) : _sink(sink), _length(0) {}
+
+  // Returns the number of bytes sent to the Print implementation.
+  // This is very handy for implementations of printTo() that must return the
+  // number of bytes written.
+  size_t bytesWritten() const {
+    return _length;
+  }
+
+  void beginArray() {
+    writeRaw('[');
+  }
+  void endArray() {
+    writeRaw(']');
+  }
+
+  void beginObject() {
+    writeRaw('{');
+  }
+  void endObject() {
+    writeRaw('}');
+  }
+
+  void writeColon() {
+    writeRaw(':');
+  }
+  void writeComma() {
+    writeRaw(',');
+  }
+
+  void writeBoolean(bool value) {
+    writeRaw(value ? "true" : "false");
+  }
+
+  void writeString(const char *value) {
+    if (!value) {
+      writeRaw("null");
+    } else {
+      writeRaw('\"');
+      while (*value) writeChar(*value++);
+      writeRaw('\"');
+    }
+  }
+
+  void writeChar(char c) {
+    char specialChar = Encoding::escapeChar(c);
+    if (specialChar) {
+      writeRaw('\\');
+      writeRaw(specialChar);
+    } else {
+      writeRaw(c);
+    }
+  }
+
+  void writeFloat(JsonFloat value, uint8_t digits = 2) {
+    if (Polyfills::isNaN(value)) return writeRaw("NaN");
+
+    if (value < 0.0) {
+      writeRaw('-');
+      value = -value;
+    }
+
+    if (Polyfills::isInfinity(value)) return writeRaw("Infinity");
+
+    short powersOf10;
+    if (value > 1000 || value < 0.001) {
+      powersOf10 = Polyfills::normalize(value);
+    } else {
+      powersOf10 = 0;
+    }
+
+    // Round up last digit (so that print(1.999, 2) prints as "2.00")
+    value += getRoundingBias(digits);
+
+    // Extract the integer part of the value and print it
+    JsonUInt int_part = static_cast<JsonUInt>(value);
+    JsonFloat remainder = value - static_cast<JsonFloat>(int_part);
+    writeInteger(int_part);
+
+    // Print the decimal point, but only if there are digits beyond
+    if (digits > 0) {
+      writeRaw('.');
+    }
+
+    // Extract digits from the remainder one at a time
+    while (digits-- > 0) {
+      // Extract digit
+      remainder *= 10.0;
+      char currentDigit = char(remainder);
+      remainder -= static_cast<JsonFloat>(currentDigit);
+
+      // Print
+      writeRaw(char('0' + currentDigit));
+    }
+
+    if (powersOf10 < 0) {
+      writeRaw("e-");
+      writeInteger(-powersOf10);
+    }
+
+    if (powersOf10 > 0) {
+      writeRaw('e');
+      writeInteger(powersOf10);
+    }
+  }
+
+  void writeInteger(JsonUInt value) {
+    char buffer[22];
+    char *ptr = buffer + sizeof(buffer) - 1;
+
+    *ptr = 0;
+    do {
+      *--ptr = static_cast<char>(value % 10 + '0');
+      value /= 10;
+    } while (value);
+
+    writeRaw(ptr);
+  }
+
+  void writeRaw(const char *s) {
+    _length += _sink.print(s);
+  }
+  void writeRaw(char c) {
+    _length += _sink.write(c);
+  }
+
+ protected:
+  Print &_sink;
+  size_t _length;
+
+ private:
+  JsonWriter &operator=(const JsonWriter &);  // cannot be assigned
+
+  static JsonFloat getLastDigit(uint8_t digits) {
+    // Designed as a compromise between code size and speed
+    switch (digits) {
+      case 0:
+        return 1e-0;
+      case 1:
+        return 1e-1;
+      case 2:
+        return 1e-2;
+      case 3:
+        return 1e-3;
+      default:
+        return getLastDigit(uint8_t(digits - 4)) * 1e-4;
+    }
+  }
+
+  FORCE_INLINE static JsonFloat getRoundingBias(uint8_t digits) {
+    return 0.5 * getLastDigit(digits);
+  }
+};
+}
+}