Specification compliant ToBigInt (to_bigint)

boa/src/builtins/bigint/conversions.rs

@@ -0,0 +1,96 @@
+use super::BigInt;
+
+use crate::{
+    builtins::{Number, Value},
+    exec::Interpreter,
+};
+use num_traits::cast::{FromPrimitive, ToPrimitive};
+
+use std::convert::TryFrom;
+use std::str::FromStr;
+
+impl BigInt {
+    /// This function takes a string and conversts it to BigInt type.
+    ///
+    /// More information:
+    ///  - [ECMAScript reference][spec]
+    ///
+    /// [spec]: https://tc39.es/ecma262/#sec-stringtobigint
+    #[inline]
+    pub(crate) fn from_string(string: &str, _ctx: &mut Interpreter) -> Result<Self, Value> {
+        if string.is_empty() {
+            return Ok(BigInt::from(0));
+        }
+
+        match num_bigint::BigInt::from_str(string) {
+            Ok(bigint) => Ok(Self(bigint)),
+            _ => panic!("SyntaxError: cannot convert {} to a BigInt", string),
+        }
+    }
+
+    /// Converts a string to a BigInt with the specified radix.
+    #[inline]
+    pub fn from_string_radix(buf: &str, radix: u32) -> Option<Self> {
+        num_bigint::BigInt::parse_bytes(buf.as_bytes(), radix).map(Self)
+    }
+
+    /// Convert bigint to string with radix.
+    #[inline]
+    pub fn to_string_radix(&self, radix: u32) -> String {
+        self.0.to_str_radix(radix)
+    }
+
+    /// Converts the BigInt to a f64 type.
+    ///
+    /// Returns `std::f64::INFINITY` if the BigInt is too big.
+    #[inline]
+    pub fn to_f64(&self) -> f64 {
+        self.0.to_f64().unwrap_or(std::f64::INFINITY)
+    }
+
+    #[inline]
+    pub(crate) fn from_str(string: &str) -> Option<Self> {
+        match num_bigint::BigInt::from_str(string) {
+            Ok(bigint) => Some(BigInt(bigint)),
+            Err(_) => None,
+        }
+    }
+}
+
+impl From<i64> for BigInt {
+    fn from(n: i64) -> BigInt {
+        BigInt(num_bigint::BigInt::from(n))
+    }
+}
+
+impl From<i32> for BigInt {
+    fn from(n: i32) -> BigInt {
+        BigInt(num_bigint::BigInt::from(n))
+    }
+}
+
+#[derive(Debug, Clone, Copy, Hash, PartialEq, Eq, PartialOrd, Ord)]
+pub struct TryFromF64Error;
+
+impl std::fmt::Display for TryFromF64Error {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "Could not convert f64 value to a BigInt type")
+    }
+}
+
+impl TryFrom<f64> for BigInt {
+    type Error = TryFromF64Error;
+
+    fn try_from(n: f64) -> Result<Self, Self::Error> {
+        // If the truncated version of the number is not the
+        // same as the non-truncated version then the floating-point
+        // number conains a fractional part.
+        if !Number::equal(n.trunc(), n) {
+            return Err(TryFromF64Error);
+        }
+        match num_bigint::BigInt::from_f64(n) {
+            Some(bigint) => Ok(BigInt(bigint)),
+            None => Err(TryFromF64Error),
+        }
+    }
+}

boa/src/builtins/bigint/equality.rs

@@ -0,0 +1,74 @@
+use super::BigInt;
+
+impl BigInt {
+    /// Checks for `SameValueZero` equality.
+    ///
+    /// More information:
+    ///  - [ECMAScript reference][spec]
+    ///
+    /// [spec]: https://tc39.es/ecma262/#sec-numeric-types-bigint-equal
+    #[inline]
+    pub(crate) fn same_value_zero(x: &Self, y: &Self) -> bool {
+        // Return BigInt::equal(x, y)
+        Self::equal(x, y)
+    }
+
+    /// Checks for `SameValue` equality.
+    ///
+    ///
+    /// More information:
+    ///  - [ECMAScript reference][spec]
+    ///
+    /// [spec]: https://tc39.es/ecma262/#sec-numeric-types-bigint-sameValue
+    #[inline]
+    pub(crate) fn same_value(x: &Self, y: &Self) -> bool {
+        // Return BigInt::equal(x, y)
+        Self::equal(x, y)
+    }
+
+    /// Checks for mathematical equality.
+    ///
+    /// The abstract operation BigInt::equal takes arguments x (a `BigInt`) and y (a `BigInt`).
+    /// It returns `true` if x and y have the same mathematical integer value and false otherwise.
+    ///
+    /// More information:
+    ///  - [ECMAScript reference][spec]
+    ///
+    /// [spec]: https://tc39.es/ecma262/#sec-numeric-types-bigint-sameValueZero
+    #[inline]
+    pub(crate) fn equal(x: &Self, y: &Self) -> bool {
+        x == y
+    }
+}
+
+impl PartialEq<i32> for BigInt {
+    fn eq(&self, other: &i32) -> bool {
+        self.0 == num_bigint::BigInt::from(*other)
+    }
+}
+
+impl PartialEq<BigInt> for i32 {
+    fn eq(&self, other: &BigInt) -> bool {
+        num_bigint::BigInt::from(*self) == other.0
+    }
+}
+
+impl PartialEq<f64> for BigInt {
+    fn eq(&self, other: &f64) -> bool {
+        if other.fract() != 0.0 {
+            return false;
+        }
+
+        self.0 == num_bigint::BigInt::from(*other as i64)
+    }
+}
+
+impl PartialEq<BigInt> for f64 {
+    fn eq(&self, other: &BigInt) -> bool {
+        if self.fract() != 0.0 {
+            return false;
+        }
+
+        num_bigint::BigInt::from(*self as i64) == other.0
+    }
+}

boa/src/builtins/bigint/mod.rs

@@ -15,21 +15,67 @@
 use crate::{
     builtins::{
         function::{make_builtin_fn, make_constructor_fn},
-        value::{ResultValue, Value},
+        value::{ResultValue, Value, ValueData},
     },
     exec::Interpreter,
-    syntax::ast::bigint::BigInt as AstBigInt,
     BoaProfiler,
 };
 
+use gc::{unsafe_empty_trace, Finalize, Trace};
+
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+
+pub mod conversions;
+pub mod equality;
+pub mod operations;
+
+pub use conversions::*;
+pub use equality::*;
+pub use operations::*;
+
 #[cfg(test)]
 mod tests;
 
 /// `BigInt` implementation.
-#[derive(Debug, Clone, Copy)]
-pub(crate) struct BigInt;
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[derive(Clone, Hash, PartialEq, Eq, PartialOrd, Ord, Default)]
+pub struct BigInt(num_bigint::BigInt);
 
 impl BigInt {
+    /// The abstract operation thisBigIntValue takes argument value.
+    ///
+    /// The phrase “this BigInt value” within the specification of a method refers to the
+    /// result returned by calling the abstract operation thisBigIntValue with the `this` value
+    /// of the method invocation passed as the argument.
+    ///
+    /// More information:
+    ///  - [ECMAScript reference][spec]
+    ///
+    /// [spec]: https://tc39.es/ecma262/#sec-thisbigintvalue
+    #[inline]
+    fn this_bigint_value(value: &Value, ctx: &mut Interpreter) -> Result<Self, Value> {
+        match value.data() {
+            // 1. If Type(value) is BigInt, return value.
+            ValueData::BigInt(ref bigint) => return Ok(bigint.clone()),
+
+            // 2. If Type(value) is Object and value has a [[BigIntData]] internal slot, then
+            //    a. Assert: Type(value.[[BigIntData]]) is BigInt.
+            //    b. Return value.[[BigIntData]].
+            ValueData::Object(_) => {
+                let bigint = value.get_internal_slot("BigIntData");
+                if let ValueData::BigInt(bigint) = bigint.data() {
+                    return Ok(bigint.clone());
+                }
+            }
+            _ => {}
+        }
+
+        // 3. Throw a TypeError exception.
+        ctx.throw_type_error("'this' is not a BigInt")?;
+        unreachable!();
+    }
+
     /// `BigInt()`
     ///
     /// The `BigInt()` constructor is used to create BigInt objects.
@@ -46,34 +92,12 @@ impl BigInt {
         ctx: &mut Interpreter,
     ) -> ResultValue {
         let data = match args.get(0) {
-            Some(ref value) => {
-                if let Some(bigint) = value.to_bigint() {
-                    Value::from(bigint)
-                } else {
-                    let message = format!(
-                        "{} can't be converted to BigInt because it isn't an integer",
-                        ctx.to_string(value)?
-                    );
-                    return ctx.throw_range_error(message);
-                }
-            }
-            None => Value::from(AstBigInt::from(0)),
+            Some(ref value) => Value::from(ctx.to_bigint(value)?),
+            None => Value::from(Self::from(0)),
         };
         Ok(data)
     }
 
-    #[inline]
-    #[allow(clippy::wrong_self_convention)]
-    pub(crate) fn to_native_string_radix(bigint: &AstBigInt, radix: u32) -> String {
-        bigint.to_str_radix(radix)
-    }
-
-    #[inline]
-    #[allow(clippy::wrong_self_convention)]
-    pub(crate) fn to_native_string(bigint: &AstBigInt) -> String {
-        bigint.to_string()
-    }
-
     /// `BigInt.prototype.toString( [radix] )`
     ///
     /// The `toString()` method returns a string representing the specified BigInt object.
@@ -99,10 +123,9 @@ impl BigInt {
             return ctx
                 .throw_range_error("radix must be an integer at least 2 and no greater than 36");
         }
-        Ok(Value::from(Self::to_native_string_radix(
-            &this.to_bigint().unwrap(),
-            radix as u32,
-        )))
+        Ok(Value::from(
+            Self::this_bigint_value(this, ctx)?.to_string_radix(radix as u32),
+        ))
     }
 
     /// `BigInt.prototype.valueOf()`
@@ -118,17 +141,15 @@ impl BigInt {
     pub(crate) fn value_of(
         this: &mut Value,
         _args: &[Value],
-        _ctx: &mut Interpreter,
+        ctx: &mut Interpreter,
     ) -> ResultValue {
-        Ok(Value::from(
-            this.to_bigint().expect("BigInt.prototype.valueOf"),
-        ))
+        Ok(Value::from(Self::this_bigint_value(this, ctx)?))
     }
 
     /// Create a new `Number` object
     pub(crate) fn create(global: &Value) -> Value {
         let prototype = Value::new_object(Some(global));
-        prototype.set_internal_slot("BigIntData", Value::from(AstBigInt::from(0)));
+        prototype.set_internal_slot("BigIntData", Value::from(Self::from(0)));
 
         make_builtin_fn(Self::to_string, "toString", &prototype, 1);
         make_builtin_fn(Self::value_of, "valueOf", &prototype, 0);
@@ -143,3 +164,11 @@ impl BigInt {
         global.set_field("BigInt", Self::create(global));
     }
 }
+
+impl Finalize for BigInt {}
+unsafe impl Trace for BigInt {
+    // BigInt type implements an empty trace becasue the inner structure
+    // `num_bigint::BigInt` does not implement `Trace` trait.
+    // If it did this would be unsound.
+    unsafe_empty_trace!();
+}