Change the structure of the .erg directory

compiler/erg_compiler/lib/std/_prelude.er

@@ -0,0 +1,82 @@
+@Attach NeImpl
+Eq(R := Self) = Trait {
+    .`==` = (self: Self, R) -> Bool
+}
+
+NeImpl R = Patch Eq R
+NeImpl(R).
+    `!=`(self, other: R): Bool = not(self == other)
+
+@Attach EqImpl, LeImpl, LtImpl, GeImpl, GtImpl
+PartialOrd(R := Self) = Trait {
+    .cmp = (self: Self, R) -> Option Ordering
+}
+Ord = Subsume PartialOrd()
+
+EqForOrd R = Patch Ord, Impl := Eq()
+EqForOrd(R).
+    `==`(self, other: R): Bool = self.cmp(other) == Ordering.Equal
+
+LeForOrd = Patch Ord
+LeForOrd.
+    `<=`(self, other: Self): Bool = self.cmp(other) == Ordering.Less or self == other
+LtForOrd = Patch Ord
+LtForOrd.
+    `<`(self, other: Self): Bool = self.cmp(other) == Ordering.Less
+GeForOrd = Patch Ord
+GeForOrd.
+    `>=`(self, other: Self): Bool = self.cmp(other) == Ordering.Greater or self == other
+GtForOrd = Patch Ord
+GtForOrd.
+    `>`(self, other: Self): Bool = self.cmp(other) == Ordering.Greater
+
+Add(R := Self) = Trait {
+    .Output = Type
+    .`_+_` = (self: Self, R) -> Self.Output
+}
+Sub(R := Self) = Trait {
+    .Output = Type
+    .`_-_` = (self: Self, R) -> Self.Output
+}
+Mul(R := Self()) = Trait {
+    .Output = Type
+    .`*` = (self: Self, R) -> Self.Output
+}
+Div(R := Self) = Trait {
+    .Output = Type
+    .`/` = (self: Self, R) -> Self.Output or Panic
+}
+Num: (R := Type) -> Type
+Num = Add and Sub and Mul
+
+Seq T = Trait {
+    .__len__ = (self: Ref(Self)) -> Nat
+    .get = (self: Ref(Self), Nat) -> T
+}
+
+`_+_`: |R: Type, A <: Add(R)| (A, R) -> A.AddO
+`_-_`: |R: Type, S <: Add(R)| (S, R) -> S.SubO
+`*`: |R, O: Type, M <: Add(R)| (M, R) -> M.MulO
+`/`: |R, O: Type, D <: Add(R)| (D, R) -> D.DivO
+
+AddForInt = Patch Int, Impl := Add()
+AddForInt.AddO = Int
+AddForInt.
+    `_+_`: (self: Self, other: Int) -> Int = magic("Add.`_+_`")
+
+# TODO: Mul and Div
+NumForInterval M, N, O, P: Int =
+    Patch M..N, Impl := Add(R := O..P) and Sub(R := O..P)
+NumForInterval(M, N, O, P).
+    `_+_`: (self: Self, other: O..P) -> M+O..N+P = magic("NumForInterval.`_+_`")
+    `_-_`: (self: Self, other: O..P) -> M-P..N-O = magic("NumForInterval.`_-_`")
+
+Read = Trait {
+    .read = (self: Ref(Self)) -> Str
+}
+Read! = Trait {
+    .read! = (self: Ref!(Self)) => Str
+}
+Write! = Trait {
+    .write! = (self: Ref!(Self), Str) => ()
+}