Moved hypot to native function to guarantee correct implementation

Author: rben01

core/desugarer.cpp

@@ -36,7 +36,7 @@ struct BuiltinDecl {
     std::vector<UString> params;
 };
 
-static unsigned long max_builtin = 39;
+static unsigned long max_builtin = 40;
 BuiltinDecl jsonnet_builtin_decl(unsigned long builtin)
 {
     switch (builtin) {
@@ -80,6 +80,7 @@ BuiltinDecl jsonnet_builtin_decl(unsigned long builtin)
         case 37: return {U"encodeUTF8", {U"str"}};
         case 38: return {U"decodeUTF8", {U"arr"}};
         case 39: return {U"atan2", {U"y", U"x"}};
+        case 40: return {U"hypot", {U"a", U"b"}};
         default:
             std::cerr << "INTERNAL ERROR: Unrecognized builtin function: " << builtin << std::endl;
             std::abort();

core/vm.cpp

@@ -938,6 +938,7 @@ class Interpreter {
         builtins["encodeUTF8"] = &Interpreter::builtinEncodeUTF8;
         builtins["decodeUTF8"] = &Interpreter::builtinDecodeUTF8;
         builtins["atan2"] = &Interpreter::builtinAtan2;
+        builtins["hypot"] = &Interpreter::builtinHypot;
 
         DesugaredObject *stdlib = makeStdlibAST(alloc, "__internal__");
         jsonnet_static_analysis(stdlib);
@@ -1107,6 +1108,13 @@ class Interpreter {
         return nullptr;
     }
 
+    const AST *builtinHypot(const LocationRange &loc, const std::vector<Value> &args)
+    {
+        validateBuiltinArgs(loc, "atan2", args, {Value::NUMBER, Value::NUMBER});
+        scratch = makeNumberCheck(loc, std::hypot(args[0].v.d, args[1].v.d));
+        return nullptr;
+    }
+
     const AST *builtinType(const LocationRange &, const std::vector<Value> &args)
     {
         switch (args[0].t) {

stdlib/std.jsonnet

@@ -267,16 +267,6 @@ limitations under the License.
   deg2rad(x):: x * std.pi / 180,
   rad2deg(x):: x * 180 / std.pi,
 
-  hypot(a, b)::
-    // copied from
-    // https://www.johndcook.com/blog/2010/06/02/whats-so-hard-about-finding-a-hypotenuse/
-    local a_abs = std.abs(a);
-    local b_abs = std.abs(b);
-    local max = std.max(a_abs, b_abs);
-    local min = std.min(a_abs, b_abs);
-    local r = min / max;
-    max * std.sqrt(1 + r * r),
-
   log2(x):: std.log(x) / std.log(2),
   log10(x):: std.log(x) / std.log(10),