Add a few missing methods to the API of Int8

Library/Hylo/Core/Numbers/Integers/Int.hylo

@@ -30,10 +30,10 @@ public type Int {
     if r == 0 {
       return self.copy()
     } else if r < 0 {
-      return -(abs() - r);
+      return -(abs() - r)
     }
 
-    return self + stride - r;
+    return self + stride - r
   }
 
   /// Returns `self`.

Library/Hylo/Core/Numbers/Integers/Int8.hylo

@@ -5,9 +5,9 @@ public type Int8 {
 
   memberwise init
 
-  /// Creates an instance with value `0`.
-  public init() {
-    &self.value = Builtin.zeroinitializer_i8()
+  /// Creates an instance with the same memory representation as `other`.
+  public init(bit_pattern other: UInt8) {
+    &self.value = other.value
   }
 
   /// Creates a copy of `other`.
@@ -30,3 +30,102 @@ public conformance Int8: Copyable {
   }
 
 }
+
+public conformance Int8: Equatable {
+
+  public fun infix== (_ other: Self) -> Bool {
+    Bool(value: Builtin.icmp_eq_i8(value, other.value))
+  }
+
+  public fun infix!= (_ other: Self) -> Bool {
+    Bool(value: Builtin.icmp_ne_i8(value, other.value))
+  }
+
+}
+
+public conformance Int8: Comparable {
+
+  public fun infix< (_ other: Self) -> Bool {
+    Bool(value: Builtin.icmp_slt_i8(value, other.value))
+  }
+
+  public fun infix<= (_ other: Self) -> Bool {
+    Bool(value: Builtin.icmp_sle_i8(value, other.value))
+  }
+
+  public fun infix> (_ other: Self) -> Bool {
+    Bool(value: Builtin.icmp_sgt_i8(value, other.value))
+  }
+
+  public fun infix>= (_ other: Self) -> Bool {
+    Bool(value: Builtin.icmp_sge_i8(value, other.value))
+  }
+
+}
+
+public conformance Int8: AdditiveArithmetic {
+
+  public fun infix+ (_ other: Self) -> Self {
+    Int8(value: Builtin.add_i8(value, other.value))
+  }
+
+  public fun infix+= (_ other: Self) inout {
+    &self.value = Builtin.add_i8(value, other.value)
+  }
+
+  public fun infix- (_ other: Self) -> Self {
+    Int8(value: Builtin.sub_i8(value, other.value))
+  }
+
+  public fun infix-= (_ other: Self) inout {
+    &self.value = Builtin.sub_i8(value, other.value)
+  }
+
+  public static fun zero() -> Self {
+    Int8()
+  }
+
+}
+
+public conformance Int8: Numeric {
+
+  public typealias Magnitude = UInt8
+
+  public fun magnitude() -> UInt8 {
+    UInt8(bit_pattern: self)
+  }
+
+  public fun infix* (_ other: Self) -> Self {
+    Int8(value: Builtin.mul_i8(value, other.value))
+  }
+
+  public fun infix*= (_ other: Self) inout {
+    &self.value = Builtin.mul_i8(value, other.value)
+  }
+
+}
+
+public conformance Int8: SignedNumeric {
+
+  public fun prefix- () -> Self {
+    Int8() - self
+  }
+
+  public fun negate() inout {
+    &self = -self
+  }
+
+}
+
+public extension Int8 {
+
+  public init() {
+    &self.value = Builtin.zeroinitializer_i8()
+  }
+
+  public init<T: BinaryInteger>(truncating_or_extending source: T) {
+    let w = source.words()
+    &self.value = Builtin.trunc_word_i8(w[w.start_index()].value)
+  }
+
+}

Library/Hylo/Core/Numbers/Integers/UInt8.hylo

@@ -0,0 +1,30 @@
+/// A 8-bit unsigned integer value.
+public type UInt8 {
+
+  var value: Builtin.i8
+
+  memberwise init
+
+  /// Creates an instance with value `0`.
+  public init() {
+    &self.value = Builtin.zeroinitializer_i8()
+  }
+
+  /// Creates an instance with the same memory representation as `other`.
+  public init(bit_pattern other: Int8) {
+    &self.value = other.value
+  }
+
+}
+
+public conformance UInt8: ExpressibleByIntegerLiteral {}
+
+public conformance UInt8: Deinitializable {}
+
+public conformance UInt8: Copyable {
+
+  public fun copy() -> Self {
+    UInt8(value: value)
+  }
+
+}