Struct brainfuck::tape::ArrayTape
[−]
[src]
pub struct ArrayTape {
// some fields omitted
}A tape with statically allocated cells.
This tape is implemented with a [u8] so it uses the memory for all
30,000 cells all the time, but allocation is done up front. The cells
are of type u8, and the tape's length is forced to be no greater
than TAPE_LENGTH so this tape is nice.
Methods from Deref<Target=u8>
fn count_ones(self) -> u32
Returns the number of ones in the binary representation of self.
Examples
Basic usage:
let n = 0b01001100u8; assert_eq!(n.count_ones(), 3);
fn count_zeros(self) -> u32
Returns the number of zeros in the binary representation of self.
Examples
Basic usage:
let n = 0b01001100u8; assert_eq!(n.count_zeros(), 5);
fn leading_zeros(self) -> u32
Returns the number of leading zeros in the binary representation
of self.
Examples
Basic usage:
let n = 0b0101000u16; assert_eq!(n.leading_zeros(), 10);
fn trailing_zeros(self) -> u32
Returns the number of trailing zeros in the binary representation
of self.
Examples
Basic usage:
let n = 0b0101000u16; assert_eq!(n.trailing_zeros(), 3);
fn rotate_left(self, n: u32) -> u8
Shifts the bits to the left by a specified amount, n,
wrapping the truncated bits to the end of the resulting integer.
Examples
Basic usage:
let n = 0x0123456789ABCDEFu64; let m = 0x3456789ABCDEF012u64; assert_eq!(n.rotate_left(12), m);
fn rotate_right(self, n: u32) -> u8
Shifts the bits to the right by a specified amount, n,
wrapping the truncated bits to the beginning of the resulting
integer.
Examples
Basic usage:
let n = 0x0123456789ABCDEFu64; let m = 0xDEF0123456789ABCu64; assert_eq!(n.rotate_right(12), m);
fn swap_bytes(self) -> u8
Reverses the byte order of the integer.
Examples
Basic usage:
let n = 0x0123456789ABCDEFu64; let m = 0xEFCDAB8967452301u64; assert_eq!(n.swap_bytes(), m);
fn to_be(self) -> u8
Converts self to big endian from the target's endianness.
On big endian this is a no-op. On little endian the bytes are swapped.
Examples
Basic usage:
let n = 0x0123456789ABCDEFu64; if cfg!(target_endian = "big") { assert_eq!(n.to_be(), n) } else { assert_eq!(n.to_be(), n.swap_bytes()) }
fn to_le(self) -> u8
Converts self to little endian from the target's endianness.
On little endian this is a no-op. On big endian the bytes are swapped.
Examples
Basic usage:
let n = 0x0123456789ABCDEFu64; if cfg!(target_endian = "little") { assert_eq!(n.to_le(), n) } else { assert_eq!(n.to_le(), n.swap_bytes()) }
fn checked_add(self, other: u8) -> Option<u8>
Checked integer addition. Computes self + other, returning None
if overflow occurred.
Examples
Basic usage:
assert_eq!(5u16.checked_add(65530), Some(65535)); assert_eq!(6u16.checked_add(65530), None);
fn checked_sub(self, other: u8) -> Option<u8>
Checked integer subtraction. Computes self - other, returning
None if underflow occurred.
Examples
Basic usage:
assert_eq!((-127i8).checked_sub(1), Some(-128)); assert_eq!((-128i8).checked_sub(1), None);
fn checked_mul(self, other: u8) -> Option<u8>
Checked integer multiplication. Computes self * other, returning
None if underflow or overflow occurred.
Examples
Basic usage:
assert_eq!(5u8.checked_mul(51), Some(255)); assert_eq!(5u8.checked_mul(52), None);
fn checked_div(self, other: u8) -> Option<u8>
Checked integer division. Computes self / other, returning None
if other == 0 or the operation results in underflow or overflow.
Examples
Basic usage:
assert_eq!((-127i8).checked_div(-1), Some(127)); assert_eq!((-128i8).checked_div(-1), None); assert_eq!((1i8).checked_div(0), None);
fn saturating_add(self, other: u8) -> u8
Saturating integer addition. Computes self + other, saturating at
the numeric bounds instead of overflowing.
Examples
Basic usage:
assert_eq!(100i8.saturating_add(1), 101); assert_eq!(100i8.saturating_add(127), 127);
fn saturating_sub(self, other: u8) -> u8
Saturating integer subtraction. Computes self - other, saturating
at the numeric bounds instead of overflowing.
Examples
Basic usage:
assert_eq!(100i8.saturating_sub(127), -27); assert_eq!((-100i8).saturating_sub(127), -128);
fn wrapping_add(self, rhs: u8) -> u8
Wrapping (modular) addition. Computes self + other,
wrapping around at the boundary of the type.
Examples
Basic usage:
assert_eq!(100i8.wrapping_add(27), 127); assert_eq!(100i8.wrapping_add(127), -29);
fn wrapping_sub(self, rhs: u8) -> u8
Wrapping (modular) subtraction. Computes self - other,
wrapping around at the boundary of the type.
Examples
Basic usage:
assert_eq!(0i8.wrapping_sub(127), -127); assert_eq!((-2i8).wrapping_sub(127), 127);
fn wrapping_mul(self, rhs: u8) -> u8
Wrapping (modular) multiplication. Computes self * other, wrapping around at the boundary of the type.
Examples
Basic usage:
assert_eq!(10i8.wrapping_mul(12), 120); assert_eq!(11i8.wrapping_mul(12), -124);
fn wrapping_div(self, rhs: u8) -> u8
Wrapping (modular) division. Computes self / other,
wrapping around at the boundary of the type.
The only case where such wrapping can occur is when one
divides MIN / -1 on a signed type (where MIN is the
negative minimal value for the type); this is equivalent
to -MIN, a positive value that is too large to represent
in the type. In such a case, this function returns MIN
itself.
Examples
Basic usage:
assert_eq!(100u8.wrapping_div(10), 10); assert_eq!((-128i8).wrapping_div(-1), -128);
fn wrapping_rem(self, rhs: u8) -> u8
Wrapping (modular) remainder. Computes self % other,
wrapping around at the boundary of the type.
Such wrap-around never actually occurs mathematically;
implementation artifacts make x % y invalid for MIN / -1 on a signed type (where MIN is the negative
minimal value). In such a case, this function returns 0.
Examples
Basic usage:
assert_eq!(100i8.wrapping_rem(10), 0); assert_eq!((-128i8).wrapping_rem(-1), 0);
fn wrapping_neg(self) -> u8
Wrapping (modular) negation. Computes -self,
wrapping around at the boundary of the type.
The only case where such wrapping can occur is when one
negates MIN on a signed type (where MIN is the
negative minimal value for the type); this is a positive
value that is too large to represent in the type. In such
a case, this function returns MIN itself.
Examples
Basic usage:
assert_eq!(100i8.wrapping_neg(), -100); assert_eq!((-128i8).wrapping_neg(), -128);
fn wrapping_shl(self, rhs: u32) -> u8
Panic-free bitwise shift-left; yields self << mask(rhs),
where mask removes any high-order bits of rhs that
would cause the shift to exceed the bitwidth of the type.
Examples
Basic usage:
assert_eq!(1u8.wrapping_shl(7), 128); assert_eq!(1u8.wrapping_shl(8), 1);
fn wrapping_shr(self, rhs: u32) -> u8
Panic-free bitwise shift-right; yields self >> mask(rhs),
where mask removes any high-order bits of rhs that
would cause the shift to exceed the bitwidth of the type.
Examples
Basic usage:
assert_eq!(128u8.wrapping_shr(7), 1); assert_eq!(128u8.wrapping_shr(8), 128);
fn pow(self, exp: u32) -> u8
Raises self to the power of exp, using exponentiation by squaring.
Examples
Basic usage:
assert_eq!(2i32.pow(4), 16);
fn is_power_of_two(self) -> bool
Returns true if and only if self == 2^k for some k.
Examples
Basic usage:
assert!(16u8.is_power_of_two()); assert!(!10u8.is_power_of_two());
fn next_power_of_two(self) -> u8
Returns the smallest power of two greater than or equal to self.
Unspecified behavior on overflow.
Examples
Basic usage:
assert_eq!(2u8.next_power_of_two(), 2); assert_eq!(3u8.next_power_of_two(), 4);
fn checked_next_power_of_two(self) -> Option<u8>
Returns the smallest power of two greater than or equal to n. If
the next power of two is greater than the type's maximum value,
None is returned, otherwise the power of two is wrapped in Some.
Examples
Basic usage:
assert_eq!(2u8.checked_next_power_of_two(), Some(2)); assert_eq!(3u8.checked_next_power_of_two(), Some(4)); assert_eq!(200u8.checked_next_power_of_two(), None);