add bigint

Author: devsnek

napi-inl.h

@@ -287,6 +287,10 @@ inline bool Value::IsNumber() const {
   return Type() == napi_number;
 }
 
+inline bool Value::IsBigInt() const {
+  return Type() == napi_bigint;
+}
+
 inline bool Value::IsString() const {
   return Type() == napi_string;
 }
@@ -505,6 +509,67 @@ inline double Number::DoubleValue() const {
   return result;
 }
 
+////////////////////////////////////////////////////////////////////////////////
+// BigInt Class
+////////////////////////////////////////////////////////////////////////////////
+
+inline BigInt BigInt::New(napi_env env, int64_t val) {
+  napi_value value;
+  napi_status status = napi_create_double(env, val, &value);
+  NAPI_THROW_IF_FAILED(env, status, BigInt());
+  return BigInt(env, value);
+}
+
+inline BigInt BigInt::New(napi_env env, uint64_t val) {
+  napi_value value;
+  napi_status status = napi_create_bigint_uint64(env, val, &value);
+  NAPI_THROW_IF_FAILED(env, status, BigInt());
+  return BigInt(env, value);
+}
+
+inline BigInt BigInt::New(napi_env env, int sign_bit, size_t word_count, uint64_t* words) {
+  napi_value value;
+  napi_status status = napi_create_bigint_words(env, sign_bit, word_count, words, &value);
+  NAPI_THROW_IF_FAILED(env, status, BigInt());
+  return BigInt(env, value);
+}
+
+inline BigInt::BigInt() : Value() {
+}
+
+inline BigInt::BigInt(napi_env env, napi_value value) : Value(env, value) {
+}
+
+inline int64_t BigInt::Int64Value(bool* lossless) const {
+  int64_t result;
+  napi_status status = napi_get_value_bigint_int64(
+      _env, _value, &result, lossless);
+  NAPI_THROW_IF_FAILED(_env, status, 0);
+  return result;
+}
+
+inline uint64_t BigInt::Uint64Value(bool* lossless) const {
+  uint64_t result;
+  napi_status status = napi_get_value_bigint_uint64(
+      _env, _value, &result, lossless);
+  NAPI_THROW_IF_FAILED(_env, status, 0);
+  return result;
+}
+
+inline size_t BigInt::WordCount() const {
+  size_t word_count;
+  napi_status status = napi_get_bigint_word_count(_env, _value, &word_count);
+  NAPI_THROW_IF_FAILED(_env, status, 0);
+  return word_count;
+}
+
+inline void BigInt::ToWords(int* sign_bit, size_t* word_count, uint64_t* words) {
+  napi_status status = napi_get_value_bigint_words(_env, _value, sign_bit, wourd_count, words);
+  NAPI_THROW_IF_FAILED(_env, status);
+}
+
+inline void ToWords(int* sign_bit, size_t* word_count, uint64_t* words) {}
+
 ////////////////////////////////////////////////////////////////////////////////
 // Name class
 ////////////////////////////////////////////////////////////////////////////////

napi.h

@@ -52,6 +52,7 @@ namespace Napi {
   class Value;
   class Boolean;
   class Number;
+  class BigInt;
   class String;
   class Object;
   class Array;
@@ -169,6 +170,7 @@ namespace Napi {
     bool IsNull() const;        ///< Tests if a value is a null JavaScript value.
     bool IsBoolean() const;     ///< Tests if a value is a JavaScript boolean.
     bool IsNumber() const;      ///< Tests if a value is a JavaScript number.
+    bool IsBigInt() const;      ///< Tests if a value is a JavaScript bigint.
     bool IsString() const;      ///< Tests if a value is a JavaScript string.
     bool IsSymbol() const;      ///< Tests if a value is a JavaScript symbol.
     bool IsArray() const;       ///< Tests if a value is a JavaScript array.
@@ -240,6 +242,48 @@ namespace Napi {
     double DoubleValue() const;   ///< Converts a Number value to a 64-bit floating-point value.
   };
 
+  /// A JavaScript bigint value.
+  class BigInt : public Value {
+  public:
+    static BigInt New(
+      napi_env env,  ///< N-API environment
+      int64_t value, ///< Number value
+    );
+    static BigInt New(
+      napi_env env,   ///< N-API environment
+      uint64_t value, ///< Number value
+    );
+
+    /// Creates a new BigInt object using a specified sign bit and a
+    /// specified list of digits/words.
+    /// The resulting number is calculated as:
+    /// (-1)^sign_bit * (words[0] * (2^64)^0 + words[1] * (2^64)^1 + ...)
+    static BigInt New(
+      napi_env env,          ///< N-API environment
+      int sign_bit,          ///< Sign bit. 1 if negative.
+      size_t word_count,     ///< Number of words in array
+      const uint64_t* words, ///< Array of words
+    );
+
+    BigInt();                               ///< Creates a new _empty_ BigInt instance.
+    BigInt(napi_env env, napi_value value); ///< Wraps a N-API value primitive.
+
+    operator int64_t();  ///< Converts a BigInt value to a 64-bit signed integer value.
+    operator uint64_t(); ///< Converts a BigInt value to a 64-bit unsigned integer value.
+
+    int64_t Int64Value(bool* lossless);   ///< Converts a BigInt value to a 64-bit signed integer value.
+    uint64_t Uint64Value(bool* lossless); ///< Converts a BigInt value to a 64-bit unsigned integer value.
+
+    size_t WordCount(); ///< The number of 64-bit words needed to store the result of WriteWords();
+
+    /// Writes the contents of this BigInt to a specified memory location.
+    /// `sign_bit` must be provided and will be set to 1 if this BigInt is negative.
+    /// `*word_count` has to be initialized to the length of the `words` array.
+    /// Upon return, it will be set to the actual number of words that would
+    /// be needed to store this BigInt (i.e. the return value of `WordCount()`).
+    void ToWords(int* sign_bit, size_t* word_count, uint64_t* words);
+  };
+
   /// A JavaScript string or symbol value (that can be used as a property name).
   class Name : public Value {
   public: