diff.diff

diff --git a/src/core/Rat.pm b/src/core/Rat.pm
index ee4111f..7272747 100644
--- a/src/core/Rat.pm
+++ b/src/core/Rat.pm
@@ -1,5 +1,42 @@
 # XXX: should be Rational[Int, UInt64]
 my class Rat is Cool does Rational[Int, Int] {
+    method new(Int \nu = 0, Int \de = 1) {
+        nqp::stmts(
+            (my $new := nqp::create(self)),
+            nqp::if(
+                nqp::isfalse(de),
+                nqp::stmts( # 0 denominator take it verbatim to support
+                            # Inf/-Inf/NaN
+                    nqp::bindattr(
+                        $new, self.WHAT, '$!numerator',  nqp::decont(nu)
+                    ),
+                    nqp::bindattr(
+                        $new, self.WHAT, '$!denominator', nqp::decont(de)
+                    ),
+                ),
+                nqp::stmts( # normalize
+                    (my $gcd         := nqp::gcd_I(nu,   de, Int)),
+                    (my $numerator   := nqp::div_I(nu, $gcd, Int)),
+                    (my $denominator := nqp::div_I(de, $gcd, Int)),
+                    nqp::if(
+                        nqp::islt_I($denominator, 0),
+                        nqp::stmts(
+                            ($numerator   := nqp::neg_I($numerator,   Int)),
+                            ($denominator := nqp::neg_I($denominator, Int)),
+                        ),
+                    ),
+                    nqp::bindattr(
+                        $new, self.WHAT, '$!numerator',   nqp::decont($numerator)
+                    ),
+                    nqp::bindattr(
+                        $new, self.WHAT, '$!denominator', nqp::decont($denominator)
+                    ),
+                )
+            ),
+            $new,
+        );
+    }
+
     method Rat   (Rat:D: Real $?) { self }
     method FatRat(Rat:D: Real $?) { FatRat.new($!numerator, $!denominator); }
     method Range(Rat:U:) { Range.new(-Inf,Inf,:excludes-min,:excludes-max) }