1 files changed, 33 insertions, 0 deletions
diff --git a/starlark/int_generic.go b/starlark/int_generic.go
new file mode 100644
index 0000000..9e84d7f
--- /dev/null
+++ b/starlark/int_generic.go
@@ -0,0 +1,33 @@
+//+build !linux,!darwin,!dragonfly,!freebsd,!netbsd,!openbsd,!solaris darwin,arm64 !amd64,!arm64,!mips64x,!ppc64x
+
+package starlark
+
+// generic Int implementation as a union
+
+import "math/big"
+
+type intImpl struct {
+	// We use only the signed 32-bit range of small to ensure
+	// that small+small and small*small do not overflow.
+	small_ int64    // minint32 <= small <= maxint32
+	big_   *big.Int // big != nil <=> value is not representable as int32
+}
+
+// --- low-level accessors ---
+
+// get returns the small and big components of the Int.
+// small is defined only if big is nil.
+// small is sign-extended to 64 bits for ease of subsequent arithmetic.
+func (i Int) get() (small int64, big *big.Int) {
+	return i.impl.small_, i.impl.big_
+}
+
+// Precondition: math.MinInt32 <= x && x <= math.MaxInt32
+func makeSmallInt(x int64) Int {
+	return Int{intImpl{small_: x}}
+}
+
+// Precondition: x cannot be represented as int32.
+func makeBigInt(x *big.Int) Int {
+	return Int{intImpl{big_: x}}
+}