Add power operator (#240)

Author: dominik-muc

lib/Base/Int.fram

@@ -29,6 +29,12 @@ pub method mod {~__line__, ~__file__} (self : Int) (n : Int) =
   assert {msg="Division by zero"} (n != 0);
   (extern dbl_modInt : Int -> Int -> Int) self n
 
+pub method rec pow {~__line__, ~__file__} (self : Int) (n : Int) =
+  assert {msg="Negative exponential"} (n >= 0);
+  if n == 0 then 1
+  else if n % 2 == 0 then (self * self).pow (n / 2)
+  else self * (self * self).pow (n / 2)
+
 pub method neg (self : Int) = 0 - self
 
 pub method land = (extern dbl_andInt : Int -> Int -> Int)

lib/Base/Int64.fram

@@ -18,13 +18,20 @@ pub method neg = (extern dbl_negInt64 : Int64 -> Int64)
 pub method add = (extern dbl_addInt64 : Int64 -> Int64 -> Int64)
 pub method sub = (extern dbl_subInt64 : Int64 -> Int64 -> Int64)
 pub method mul = (extern dbl_mulInt64 : Int64 -> Int64 -> Int64)
+
 pub method div {~__line__, ~__file__} (self : Int64) (n : Int64) =
-  assert {msg="Division by zero"} (n.neq 0L);
+  assert {msg="Division by zero"} (n != 0L);
   (extern dbl_divInt64 : Int64 -> Int64 -> Int64) self n
 pub method mod {~__line__, ~__file__} (self : Int64) (n : Int64) =
-  assert {msg="Division by zero"} (n.neq 0L);
+  assert {msg="Division by zero"} (n != 0L);
   (extern dbl_modInt64 : Int64 -> Int64 -> Int64) self n
 
+pub method rec pow {~__line__, ~__file__} (self : Int64) (n : Int64) =
+  assert {msg="Negative exponential"} (n >= 0L);
+  if n == 0L then 1L
+  else if n % 2L == 0L then (self * self).pow (n / 2L)
+  else self * (self * self).pow (n / 2L)
+
 pub method land = (extern dbl_andInt64 : Int64 -> Int64 -> Int64)
 pub method lor  = (extern dbl_orInt64  : Int64 -> Int64 -> Int64)
 pub method lxor = (extern dbl_xorInt64 : Int64 -> Int64 -> Int64)

lib/Base/Operators.fram

@@ -19,6 +19,10 @@ pub let (/)
   , method div : {~__line__, ~__file__} -> T -> U} (x : T) =
     x.div
 pub let (*) {method mul : T -> U} (x : T) = x.mul
+pub let (**)
+  { ~__line__, ~__file__
+  , method pow : {~__line__, ~__file__} -> T -> U} (x : T) =
+    x.pow
 
 pub let (==) {method equal : T -> U} (x : T) = x.equal
 pub let (!=) {method neq   : T -> U} (x : T) = x.neq