Adds downTo(_) method on numbers

Refactors bounds checking
gracelang · May 15, 2019 · afc5692 · afc5692
1 parent 4b7249c
commit afc5692
Showing 1 changed file with 20 additions and 8 deletions.
diff --git a/js/gracelib.js b/js/gracelib.js
@@ -921,20 +921,32 @@ GraceNum.prototype = {
         },
         "..(1)": function(argcv, other) {
             if (! Number.isInteger(this._value)) {
-                throw new GraceExceptionPacket(RequestErrorObject,
-                    new GraceString("lower bound of range (" + this._value +
-                                    ") not an integer."));
+                raiseException(RequestErrorObject,
+                    "lower bound of range (" + this._value +
+                               ") not an integer.");
             } else if (other.className !== "number") {
-                throw new GraceExceptionPacket(TypeErrorObject,
-                    new GraceString("upper bound of range not a Number."));
+                raiseException(TypeErrorObject, "upper bound of range not a Number");
             } else if (! Number.isInteger(other._value)) {
-                throw new GraceExceptionPacket(RequestErrorObject,
-                    new GraceString("upper bound of range (" + other._value +
-                                    ") not an integer."));
+                raiseException(RequestErrorObject, "upper bound of range (" +
+                    other._value + ") not an integer");
             }
             return callmethod(GraceRangeClass(),
                     "uncheckedFrom(1)to(1)", [1, 1], this, other);
         },
+        "downTo(1)": function(argcv, other) {
+            if (! Number.isInteger(this._value)) {
+                raiseException(RequestErrorObject,
+                    "first bound of downward range (" + this._value +
+                               ") not an integer.");
+            } else if (other.className !== "number") {
+                raiseException(TypeErrorObject, "second bound of downward range not a Number");
+            } else if (! Number.isInteger(other._value)) {
+                raiseException(RequestErrorObject, "second bound of downward range (" +
+                    other._value + ") not an integer");
+            }
+            return callmethod(GraceRangeClass(),
+                    "from(1)downTo(1)", [1, 1], this, other);
+        },
         "compare(1)": function(argcv, that) {
             var self = this._value;
             var other = that._value;