fix(core): System_nanotime incorrectly returns double (#1470)

* fix(core): fix System_nanotime cast from long to double to long

* feat(core): add from/to uint64_t to Double.carp for Random.carp

Author: CorruptedVor

core/Double.carp

@@ -21,6 +21,8 @@
   (register from-float (Fn [Float] Double))
   (register to-long (Fn [Double] Long))
   (register from-long (Fn [Long] Double))
+  (register to-uint64 (Fn [Double] Uint64))
+  (register from-uint64 (Fn [Uint64] Double))
   (register to-bytes (Fn [Double] Long))
   (register copy (Fn [(Ref Double)] Double))
 

core/Random.carp

@@ -8,7 +8,7 @@
 
   (doc seed "seed resets the seed of the random number generator.")
   (defn seed []
-    (set! s (Double.from-long (System.nanotime))))
+    (set! s (Double.from-uint64 (System.nanotime))))
 
   (doc seed-from "seed-from resets the seed of the random number generator to `new-seed`.")
   (defn seed-from [new-seed]

core/System.carp

@@ -8,8 +8,8 @@
   (register carp-init-globals (Fn [Int (Ptr (Ptr CChar))] ()) "carp_init_globals")
   (doc time "Gets the current system time as an integer.")
   (register time (Fn [] Int))
-  (doc nanotime "Gets the current system time in nanoseconds as a long.")
-  (register nanotime (Fn [] Long))
+  (doc nanotime "Gets the current system time in nanoseconds as a uint64_t.")
+  (register nanotime (Fn [] Uint64))
   (doc sleep-seconds "Sleeps for a specified number of seconds.")
   (register sleep-seconds (Fn [Int] ()))
   (doc sleep-seconds "Sleeps for a specified number of microseconds.")

core/carp_double.h

@@ -60,6 +60,14 @@ double Double_from_MINUS_long(Long x) {
     return (double)x;
 }
 
+uint64_t Double_to_MINUS_uint64(double x) {
+    return (uint64_t)x;
+}
+
+double Double_from_MINUS_uint64(uint64_t x) {
+    return (double)x;
+}
+
 double Double_abs(double x) {
     return x > 0.0 ? x : -x;
 }

core/carp_system.h

@@ -15,7 +15,7 @@ void System_sleep_MINUS_micros(int t) {
     // TODO!
 }
 
-double System_nanotime() {
+uint64_t System_nanotime() {
     return 0;
 }
 #else
@@ -27,10 +27,10 @@ void System_sleep_MINUS_micros(int t) {
     usleep(t);
 }
 
-double System_nanotime() {
+uint64_t System_nanotime() {
     struct timespec tv;
     clock_gettime(CLOCK_REALTIME, &tv);
-    return 1000000000 * tv.tv_sec + tv.tv_nsec;
+    return (uint64_t)1000000000 * (uint64_t)tv.tv_sec + (uint64_t)tv.tv_nsec;
 }
 #endif