Add comparison operators + tests + fix shr forward declaration

src/mpint.nim

@@ -4,9 +4,11 @@
 import  ./uint_type,
         ./uint_init,
         ./uint_bitwise_ops,
-        ./uint_binary_ops
+        ./uint_binary_ops,
+        ./uint_comparison
 
 export  uint_type,
         uint_init,
         uint_bitwise_ops,
-        uint_binary_ops
+        uint_binary_ops,
+        uint_comparison

src/uint_binary_ops.nim

@@ -2,7 +2,8 @@
 # Distributed under the MIT License (license terms are at http://opensource.org/licenses/MIT).
 
 import  ./private/utils,
-        uint_type
+        uint_type,
+        uint_comparison
 
 proc `+=`*[T: MpUint](x: var T, y: T) {.noSideEffect.}=
   ## In-place addition for multi-precision unsigned int

src/uint_bitwise_ops.nim

@@ -25,7 +25,7 @@ proc `xor`*(x, y: MpUint): MpUint {.noInit, noSideEffect, inline.}=
   result.lo = x.lo xor y.lo
   result.hi = x.hi xor y.hi
 
-proc `shl`*[T: MpUint](x: T, y: SomeInteger): T {.noInit, noSideEffect.}
+proc `shr`*[T: MpUint](x: T, y: SomeInteger): T {.noInit, noSideEffect.}
   # Forward declaration
 
 proc `shl`*[T: MpUint](x: T, y: SomeInteger): T {.noInit, noSideEffect.}=

src/uint_comparison.nim

@@ -0,0 +1,13 @@
+# Copyright (c) 2018 Status Research & Development GmbH
+# Distributed under the MIT License (license terms are at http://opensource.org/licenses/MIT).
+
+import  ./uint_type
+
+proc `<`*[T: MpUint](x, y: T): bool {.noSideEffect, noInit, inline.}=
+  (x.hi < y.hi) or ((x.hi == y.hi) and x.lo < y.lo)
+
+proc `<=`*[T: MpUint](x, y: T): bool {.noSideEffect, noInit, inline.}=
+  # Lower or equal comparison for multi-precision integers
+  if x == y:
+    return true
+  x < y

tests/all_tests.nim

@@ -3,4 +3,5 @@
 
 import  test_endianness,
         test_addsub,
-        test_mul
+        test_mul,
+        test_comparison

tests/test_comparison.nim

@@ -0,0 +1,34 @@
+# Copyright (c) 2018 Status Research & Development GmbH
+# Distributed under the MIT License (license terms are at http://opensource.org/licenses/MIT).
+
+import ../src/mpint, unittest
+
+suite "Testing comparison operators":
+  let
+    a = initMpUint(10, uint8)
+    b = initMpUint(15, uint8)
+    c = 150'u16
+
+  test "< operator":
+    check: a < b
+    check: not (a + b < b)
+    check: not (a + a + a < b + b)
+    check: not (a * b < cast[Mpuint[uint8]](c))
+
+  test "<= operator":
+    check: a <= b
+    check: not (a + b <= b)
+    check: a + a + a <= b + b
+    check: a * b <= cast[Mpuint[uint8]](c)
+
+  test "> operator":
+    check: b > a
+    check: not (b > a + b)
+    check: not (b + b > a + a + a)
+    check: not (cast[Mpuint[uint8]](c) > a * b)
+
+  test ">= operator":
+    check: b >= a
+    check: not (b >= a + b)
+    check: b + b >= a + a + a
+    check: cast[Mpuint[uint8]](c) >= a * b