Merge branch 'main' into feat/to_hex_string_helper

crates/starknet-types-core/Cargo.toml

@@ -21,12 +21,15 @@ arbitrary = { version = "1.3.0", optional = true, default-features = false }
 num-traits = { version = "0.2.16", default-features = false }
 num-bigint = {version = "0.4.4",  default-features = false}
 num-integer = {version = "0.1.45",  default-features = false}
+lazy_static = { version = "1.4.0", default-features = false, features = [
+    "spin_no_std",
+] }
 
 [features]
 default = ["std", "serde", "curve"]
 curve = []
 hash = ["dep:lambdaworks-crypto"]
-std = []
+std = ["alloc"]
 alloc = ["serde?/alloc"]
 arbitrary = ["std", "dep:arbitrary"]
 

crates/starknet-types-core/src/felt.rs

@@ -1,10 +1,20 @@
 use core::ops::{Add, Mul, Neg};
 
 use bitvec::array::BitArray;
-use num_bigint::BigInt;
+use lazy_static::lazy_static;
+use num_bigint::{BigInt, BigUint, Sign};
 use num_integer::Integer;
+use num_traits::Num;
 use num_traits::{FromPrimitive, One, ToPrimitive, Zero};
 
+lazy_static! {
+    pub static ref CAIRO_PRIME_BIGINT: BigInt = BigInt::from_str_radix(
+        "800000000000011000000000000000000000000000000000000000000000001",
+        16
+    )
+    .unwrap();
+}
+
 #[cfg(target_pointer_width = "64")]
 pub type BitArrayStore = [u64; 4];
 
@@ -353,6 +363,19 @@ impl Felt {
     pub fn bits(&self) -> usize {
         self.0.representative().bits_le()
     }
+
+    pub fn to_biguint(&self) -> BigUint {
+        let big_digits = self
+            .to_le_digits()
+            .into_iter()
+            .flat_map(|limb| [limb as u32, (limb >> 32) as u32])
+            .collect();
+        BigUint::new(big_digits)
+    }
+
+    pub fn to_bigint(&self) -> BigInt {
+        self.to_biguint().into()
+    }
 }
 
 #[cfg(feature = "arbitrary")]
@@ -441,6 +464,24 @@ impl From<i128> for Felt {
     }
 }
 
+impl From<&BigInt> for Felt {
+    fn from(bigint: &BigInt) -> Felt {
+        let (sign, bytes) = bigint.mod_floor(&CAIRO_PRIME_BIGINT).to_bytes_le();
+        let felt = Felt::from_bytes_le_slice(&bytes);
+        if sign == Sign::Minus {
+            felt.neg()
+        } else {
+            felt
+        }
+    }
+}
+
+impl From<&BigUint> for Felt {
+    fn from(biguint: &BigUint) -> Felt {
+        Felt::from_bytes_le_slice(&biguint.to_bytes_le())
+    }
+}
+
 macro_rules! impl_from {
     ($from:ty, $with:ty) => {
         impl From<$from> for Felt {
@@ -1613,4 +1654,65 @@ mod test {
 
         assert_eq!(x.mul_mod(&y, &p), expected_result);
     }
+
+    #[test]
+    fn bigints_to_felt() {
+        let one = &*CAIRO_PRIME_BIGINT + BigInt::from(1_u32);
+        assert_eq!(Felt::from(&one.to_biguint().unwrap()), Felt::from(1));
+        assert_eq!(Felt::from(&one), Felt::from(1));
+
+        let zero = &*CAIRO_PRIME_BIGINT * 99_u32;
+        assert_eq!(Felt::from(&zero.to_biguint().unwrap()), Felt::from(0));
+        assert_eq!(Felt::from(&zero), Felt::from(0));
+
+        assert_eq!(
+            Felt::from(&BigInt::from(-1)),
+            Felt::from_hex("0x800000000000011000000000000000000000000000000000000000000000000")
+                .unwrap()
+        );
+
+        let numbers_str = [
+            "0x0",
+            "0x1",
+            "0x10",
+            "0x8000000000000110000000000",
+            "0xffffffffffffff",
+            "0xffffffffefff12380777abcd",
+        ];
+
+        for number_str in numbers_str {
+            assert_eq!(
+                Felt::from(&BigInt::from_str_radix(&number_str[2..], 16).unwrap()),
+                Felt::from_hex(number_str).unwrap()
+            );
+            assert_eq!(
+                Felt::from(&BigUint::from_str_radix(&number_str[2..], 16).unwrap()),
+                Felt::from_hex(number_str).unwrap()
+            )
+        }
+    }
+
+    #[test]
+    fn felt_to_bigints() {
+        let numbers_str = [
+            "0x0",
+            "0x1",
+            "0x10",
+            "0x8000000000000110000000000",
+            "0xffffffffffffff",
+            "0xffffffffefff12380777abcd",
+        ];
+
+        for number_str in numbers_str {
+            assert_eq!(
+                Felt::from_hex(number_str).unwrap().to_bigint(),
+                BigInt::from_str_radix(&number_str[2..], 16).unwrap()
+            );
+
+            assert_eq!(
+                Felt::from_hex(number_str).unwrap().to_biguint(),
+                BigUint::from_str_radix(&number_str[2..], 16).unwrap()
+            );
+        }
+    }
 }