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Operators

Arithmetic operators​

There are arithmetic operators such as +, -, *, /, **, and % available for I256 and U256 types, and these operators will check for overflow at runtime.

For example, the following expressions will cause the VM to throw an error at runtime:

u256Max!() + 1  // overflow
0 - 1           // overflow
i256Max!() + 1i // overflow
i256Min!() - 1i // overflow

Modulo 2^256 operators​

For the U256 type, there are arithmetic operators modulo 2^256: |+|, |-|, |*|, |**|. Here are some examples:

assert!(u256Max!() |+| 1 == 0, 0) // addition modulo 2^256
assert!(0 |-| 1 == u256Max!(), 0) // subtraction modulo 2^256
assert!(u256Max!() |*| 2 == u256Max!() - 1, 0) // multiplication modulo 2^256
assert!((1 << 128) |**| 2 == 0, 0) // pow modulo 2^256

Modulo N operators​

The VM also provides two advanced modulo functions for the U256 type, addModN and mulModN:

assert!(mulModN!(2, 3, 4) == 2, 0) // (2 * 3) % 4
assert!(mulModN!(1 << 128, 1 << 128, u256Max!() - 1) == 2, 0)
assert!(mulModN!(u256Max!(), u256Max!(), u256Max!()) == 0, 0)

assert!(addModN!(2, 3, 4) == 1, 0) // (2 + 3) % 4
assert!(addModN!(1 << 128, 1 << 128, u256Max!()) == 1 << 129, 0)
assert!(addModN!(u256Max!(), u256Max!(), u256Max!()) == 0, 0)

Bitwise operators​

Ralph supports bit operators such as &, |, ^, <<, and >> only for the U256 type, here are some examples:

assert!(0xff & 0xf0 == 0xf0, 0)
assert!(0xff | 0xf0 == 0xff, 0)
assert!(0xff ^ 0xf0 == 0x0f, 0)
assert!(0xff << 8 == 0xff00, 0)
assert!(u256Max!() << 2 == u256Max!() - 3, 0)
assert!(0xff >> 4 == 0x0f, 0)

Comparison operators​

There are inequality operators such as <, >, <=, and >= available for I256 and U256 types, and equality operators ==, != for all primitive types.

Note that the comparison operators cannot be used with array types or struct types.

Logical Operators​

Similar to other programming languages, Ralph also supports logical operators such as &&, ||, and !.

ByteVec Operators​

Ralph has a special operator ++ for concatenating ByteVec:

assert!(#00 ++ #11 == #0011, 0)