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#![feature(core)] |
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use std::fmt; |
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use std::iter; |
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use std::marker::MarkerTrait; |
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use std::num::{Int}; |
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trait AsByte { |
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fn as_u8(&self) -> u8; |
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fn as_i8(&self) -> i8; |
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fn not_less_than_zero(&self) -> bool; |
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fn less_than_256(&self) -> bool; |
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fn less_than_128(&self) -> bool; |
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fn not_less_than_neg128(&self) -> bool; |
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fn value_falls_in_i8_range(&self) -> bool { |
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self.not_less_than_neg128() && self.less_than_128() |
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} |
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fn value_falls_in_u8_range(&self) -> bool { |
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self.not_less_than_zero() && self.less_than_256() |
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} |
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fn value_falls_in_i8_or_u8_range(&self) -> bool { |
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self.not_less_than_neg128() && self.less_than_256() |
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} |
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} |
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trait IntTypeInfo { |
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fn signed_bit_width() -> (bool, u32); |
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fn type_is_signed() -> bool { Self::signed_bit_width().0 } |
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fn bit_width() -> u32 { Self::signed_bit_width().1 } |
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fn zero_after_rshift(&self, rhs: u32) -> bool; |
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fn ones_after_rshift(&self, rhs: u32) -> bool; |
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fn same_after_rshift(&self, rhs: u32) -> bool { |
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self.zero_after_rshift(rhs) || self.ones_after_rshift(rhs) |
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} |
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fn signbits(&self) -> Self; |
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} |
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impl IntTypeInfo for i8 { |
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fn signed_bit_width() -> (bool, u32) { (true, 8) } |
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fn signbits(&self) -> Self { |
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if *self < 0 { -1 } else { 0 } |
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} |
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fn zero_after_rshift(&self, rhs: u32) -> bool { (*self >> rhs) == 0 } |
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fn ones_after_rshift(&self, rhs: u32) -> bool { (*self >> rhs) == -1 } |
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} |
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impl IntTypeInfo for i16 { |
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fn signed_bit_width() -> (bool, u32) { (true, 16) } |
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fn signbits(&self) -> Self { |
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if *self < 0 { -1 } else { 0 } |
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} |
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fn zero_after_rshift(&self, rhs: u32) -> bool { (*self >> rhs) == 0 } |
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fn ones_after_rshift(&self, rhs: u32) -> bool { (*self >> rhs) == -1 } |
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} |
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impl IntTypeInfo for u8 { |
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fn signed_bit_width() -> (bool, u32) { (false, 8) } |
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fn signbits(&self) -> Self { 0 } |
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fn zero_after_rshift(&self, rhs: u32) -> bool { (*self >> rhs) == 0 } |
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fn ones_after_rshift(&self, rhs: u32) -> bool { (*self >> rhs) == -1 } |
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} |
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impl IntTypeInfo for u16 { |
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fn signed_bit_width() -> (bool, u32) { (false, 16) } |
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fn signbits(&self) -> Self { 0 } |
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fn zero_after_rshift(&self, rhs: u32) -> bool { (*self >> rhs) == 0 } |
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fn ones_after_rshift(&self, rhs: u32) -> bool { (*self >> rhs) == -1 } |
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} |
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impl AsByte for i8 { |
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fn as_u8(&self) -> u8 { *self as u8 } |
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fn as_i8(&self) -> i8 { *self } |
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fn less_than_128(&self) -> bool { true } |
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fn less_than_256(&self) -> bool { true } |
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fn not_less_than_zero(&self) -> bool { *self >= 0 } |
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fn not_less_than_neg128(&self) -> bool { true } |
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} |
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impl AsByte for u8 { |
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fn as_u8(&self) -> u8 { *self } |
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fn as_i8(&self) -> i8 { *self as i8 } |
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fn less_than_128(&self) -> bool { *self < 0x80 } |
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fn less_than_256(&self) -> bool { true } |
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fn not_less_than_zero(&self) -> bool { true } |
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fn not_less_than_neg128(&self) -> bool { true } |
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} |
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impl AsByte for i16 { |
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fn as_u8(&self) -> u8 { *self as u8 } |
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fn as_i8(&self) -> i8 { *self as i8 } |
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fn less_than_128(&self) -> bool { *self < 0x80 } |
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fn less_than_256(&self) -> bool { *self < 0x100 } |
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fn not_less_than_zero(&self) -> bool { *self >= 0 } |
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fn not_less_than_neg128(&self) -> bool { *self >= -128 } |
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} |
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impl AsByte for u16 { |
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fn as_u8(&self) -> u8 { *self as u8 } |
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fn as_i8(&self) -> i8 { *self as i8 } |
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fn less_than_128(&self) -> bool { *self < 0x80 } |
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fn less_than_256(&self) -> bool { *self < 0x100 } |
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fn not_less_than_zero(&self) -> bool { true } |
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fn not_less_than_neg128(&self) -> bool { true } |
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} |
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struct WidthOriented<T>(T); |
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struct StrictRange<T>(T); |
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struct LooseRange<T>(T); |
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trait NumType: MarkerTrait { fn name() -> &'static str; } |
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impl NumType for i8 { fn name() -> &'static str { "i8" } } |
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impl NumType for u8 { fn name() -> &'static str { "u8" } } |
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impl NumType for i16 { fn name() -> &'static str { "i16" } } |
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impl NumType for u16 { fn name() -> &'static str { "u16" } } |
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impl<T:NumType+fmt::LowerHex> fmt::Debug for WidthOriented<T> { |
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fn fmt(&self, w: &mut fmt::Formatter) -> fmt::Result { |
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write!(w, "WidthOriented(0x{:x}_{})", self.0, T::name()) |
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} |
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} |
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impl<T:NumType+fmt::LowerHex> fmt::Debug for StrictRange<T> { |
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fn fmt(&self, w: &mut fmt::Formatter) -> fmt::Result { |
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write!(w, "StrictRange(0x{:x}_{})", self.0, T::name()) |
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} |
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} |
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impl<T:NumType+fmt::LowerHex> fmt::Debug for LooseRange<T> { |
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fn fmt(&self, w: &mut fmt::Formatter) -> fmt::Result { |
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write!(w, "LooseRange(0x{:x}_{})", self.0, T::name()) |
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} |
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} |
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trait CheckedAsByte : AsByte { |
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fn checked_as_u8(&self) -> Option<u8>; |
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fn checked_as_i8(&self) -> Option<i8>; |
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} |
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impl<T:AsByte> AsByte for WidthOriented<T> { |
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fn as_u8(&self) -> u8 { self.0.as_u8() } |
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fn as_i8(&self) -> i8 { self.0.as_i8() } |
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fn less_than_128(&self) -> bool{ self.0.less_than_128() } |
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fn less_than_256(&self) -> bool{ self.0.less_than_256() } |
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fn not_less_than_zero(&self) -> bool{ self.0.not_less_than_zero() } |
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fn not_less_than_neg128(&self) -> bool { self.0.not_less_than_neg128() } |
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} |
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impl<T:AsByte> AsByte for StrictRange<T> { |
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fn as_u8(&self) -> u8 { self.0.as_u8() } |
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fn as_i8(&self) -> i8 { self.0.as_i8() } |
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fn less_than_128(&self) -> bool{ self.0.less_than_128() } |
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fn less_than_256(&self) -> bool{ self.0.less_than_256() } |
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fn not_less_than_zero(&self) -> bool{ self.0.not_less_than_zero() } |
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fn not_less_than_neg128(&self) -> bool{ self.0.not_less_than_neg128() } |
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} |
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impl<T:AsByte> AsByte for LooseRange<T> { |
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fn as_u8(&self) -> u8 { self.0.as_u8() } |
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fn as_i8(&self) -> i8 { self.0.as_i8() } |
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fn less_than_128(&self) -> bool{ self.0.less_than_128() } |
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fn less_than_256(&self) -> bool{ self.0.less_than_256() } |
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fn not_less_than_zero(&self) -> bool{ self.0.not_less_than_zero() } |
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fn not_less_than_neg128(&self) -> bool{ self.0.not_less_than_neg128() } |
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} |
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impl<T:Int+IntTypeInfo+AsByte+fmt::Debug> CheckedAsByte for WidthOriented<T> { |
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fn checked_as_u8(&self) -> Option<u8> { |
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if T::bit_width() == 8 || self.value_falls_in_u8_range() { |
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Some(self.as_u8()) |
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} else { |
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None |
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} |
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} |
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fn checked_as_i8(&self) -> Option<i8> { |
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if T::bit_width() == 8 || self.value_falls_in_i8_range() { |
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Some(self.as_i8()) |
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} else { |
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None |
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} |
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} |
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} |
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impl<T:Int+AsByte> CheckedAsByte for StrictRange<T> { |
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fn checked_as_u8(&self) -> Option<u8> { |
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if self.value_falls_in_u8_range() { Some(self.as_u8()) } else { None } |
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} |
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fn checked_as_i8(&self) -> Option<i8> { |
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if self.value_falls_in_i8_range() { Some(self.as_i8()) } else { None } |
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} |
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} |
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impl<T:Int+AsByte> CheckedAsByte for LooseRange<T> { |
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fn checked_as_u8(&self) -> Option<u8> { |
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if self.value_falls_in_i8_or_u8_range() { Some(self.as_u8()) } else { None } |
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} |
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fn checked_as_i8(&self) -> Option<i8> { |
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if self.value_falls_in_i8_or_u8_range() { Some(self.as_i8()) } else { None } |
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} |
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} |
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fn fill_left<T:fmt::Debug>(x: T, fill: usize) -> String { |
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let s = format!("{:?}", x); |
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if s.len() >= fill { |
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s |
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} else { |
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let indent = fill - s.len(); |
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let indent: String = iter::repeat(' ').take(indent).collect(); |
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indent + &s |
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} |
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} |
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trait Results<T>: CheckedAsByte + fmt::Debug { |
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fn inner(&self) -> T; |
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fn results(&self) -> (T, String, i8, String, u8, String) { |
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let i = self; |
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(i.inner(), fill_left(self, 25), |
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i.as_i8(), fill_left(i.checked_as_i8(), 10), |
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i.as_u8(), fill_left(i.checked_as_u8(), 10)) |
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} |
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} |
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impl<T> Results<T> for WidthOriented<T> |
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where T:Copy+NumType+fmt::LowerHex, WidthOriented<T> : CheckedAsByte { |
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fn inner(&self) -> T { self.0 } |
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} |
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impl<T> Results<T> for StrictRange<T> |
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where T:Copy+NumType+fmt::LowerHex, StrictRange<T> : CheckedAsByte { |
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fn inner(&self) -> T { self.0 } |
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} |
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impl<T> Results<T> for LooseRange<T> |
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where T:Copy+NumType+fmt::LowerHex, LooseRange<T> : CheckedAsByte { |
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fn inner(&self) -> T { self.0 } |
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} |
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fn main() { |
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let inputs = [0, 1, 0x7F]; |
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println!("TRIVIAL CASES"); |
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for &j in &inputs { |
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test_input(j); |
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} |
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println!("NONOBVIOUS CASES"); |
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let inputs = [0xFF, 0x80, 129, 0x100, 0x7FFF, 0x8000, 0xFFFF]; |
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for &j in &inputs { |
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test_input(j); |
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} |
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macro_rules! row { |
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() => { "{:>25} {:>6} {:>5} {:>10} {:>5} {:>10} " } |
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} |
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fn test_input(j: i32) { |
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println!("{:>25} {:>6} ({:>5},{:>10}) ({:>5},{:>10})", |
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"OFLO_HANDLER", "INPUT", "as i8", "checked", "as u8","checked"); |
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println!(row!(), |
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"------------", "------", "-----", "--------", "-----","--------"); |
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let i = StrictRange(j as i8); let r = i.results(); |
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println!(row!(), r.1, r.0, r.2, r.3, r.4, r.5); |
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let i = WidthOriented( j as i8); let r = i.results(); |
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println!(row!(), r.1, r.0, r.2, r.3, r.4, r.5); |
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let i = LooseRange(j as i8); let r = i.results(); |
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println!(row!(), r.1, r.0, r.2, r.3, r.4, r.5); |
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println!(""); |
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let i = StrictRange(j as u8); let r = i.results(); |
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println!(row!(), r.1, r.0, r.2, r.3, r.4, r.5); |
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let i = WidthOriented( j as u8); let r = i.results(); |
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println!(row!(), r.1, r.0, r.2, r.3, r.4, r.5); |
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let i = LooseRange(j as u8); let r = i.results(); |
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println!(row!(), r.1, r.0, r.2, r.3, r.4, r.5); |
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println!(""); |
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let i = StrictRange(j as i16); let r = i.results(); |
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println!(row!(), r.1, r.0, r.2, r.3, r.4, r.5); |
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let i = WidthOriented( j as i16); let r = i.results(); |
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println!(row!(), r.1, r.0, r.2, r.3, r.4, r.5); |
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let i = LooseRange(j as i16); let r = i.results(); |
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println!(row!(), r.1, r.0, r.2, r.3, r.4, r.5); |
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println!(""); |
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let i = StrictRange(j as u16); let r = i.results(); |
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println!(row!(), r.1, r.0, r.2, r.3, r.4, r.5); |
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let i = WidthOriented( j as u16); let r = i.results(); |
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println!(row!(), r.1, r.0, r.2, r.3, r.4, r.5); |
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let i = LooseRange(j as u16); let r = i.results(); |
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println!(row!(), r.1, r.0, r.2, r.3, r.4, r.5); |
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println!(""); |
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} |
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} |
/checked transcript non-obvious cases
Last active
This comment has been minimized.
pnkfelix commentedMar 12, 2015
linked from:
https://gist.github.com/pnkfelix/d3d97ed0f6a945e24a7a