Num; add min, max and clamp

wren-lang · Dec 3, 2020 · 8361217 · 8361217
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diff --git a/doc/site/modules/core/num.markdown b/doc/site/modules/core/num.markdown
@@ -116,6 +116,20 @@ The binary (base-2) logarithm of the number. Returns `nan` if the base is negati
 
 The exponential `e` (Euler’s number) raised to the number. This: `eⁿ`. 
 
+### **min**(other)
+
+Returns the minimum value when comparing this number and `other`.
+
+### **max**(other)
+
+Returns the maximum value when comparing this number and `other`.
+
+### **clamp**(min, max)
+
+Clamps a number into the range of `min` and `max`. If this number is less than min, 
+`min` is returned. If bigger than `max`, `max` is returned. Otherwise, the number 
+itself is returned.
+
 ### **pow**(power)
 
 Raises this number (the base) to `power`. Returns `nan` if the base is negative.

diff --git a/src/vm/wren_core.c b/src/vm/wren_core.c
@@ -735,6 +735,29 @@ DEF_PRIMITIVE(num_atan2)
   RETURN_NUM(atan2(AS_NUM(args[0]), AS_NUM(args[1])));
 }
 
+DEF_PRIMITIVE(num_min)
+{
+  double value = AS_NUM(args[0]);
+  double other = AS_NUM(args[1]);
+  RETURN_NUM(value <= other ? value : other);
+}
+
+DEF_PRIMITIVE(num_max)
+{
+  double value = AS_NUM(args[0]);
+  double other = AS_NUM(args[1]);
+  RETURN_NUM(value > other ? value : other);
+}
+
+DEF_PRIMITIVE(num_clamp)
+{
+  double value = AS_NUM(args[0]);
+  double min = AS_NUM(args[1]);
+  double max = AS_NUM(args[2]);
+  double result = (value < min) ? min : ((value > max) ? max : value);
+  RETURN_NUM(result);
+}
+
 DEF_PRIMITIVE(num_pow)
 {
   RETURN_NUM(pow(AS_NUM(args[0]), AS_NUM(args[1])));
@@ -1325,6 +1348,9 @@ void wrenInitializeCore(WrenVM* vm)
   PRIMITIVE(vm->numClass, "floor", num_floor);
   PRIMITIVE(vm->numClass, "-", num_negate);
   PRIMITIVE(vm->numClass, "round", num_round);
+  PRIMITIVE(vm->numClass, "min(_)", num_min);
+  PRIMITIVE(vm->numClass, "max(_)", num_max);
+  PRIMITIVE(vm->numClass, "clamp(_,_)", num_clamp);
   PRIMITIVE(vm->numClass, "sin", num_sin);
   PRIMITIVE(vm->numClass, "sqrt", num_sqrt);
   PRIMITIVE(vm->numClass, "tan", num_tan);

diff --git a/test/core/number/clamp.wren b/test/core/number/clamp.wren
@@ -0,0 +1,7 @@
+var num = 4
+
+System.print(num.clamp(0, 10)) // expect: 4
+System.print(num.clamp(0, 1)) // expect: 1
+System.print(2.clamp(0, 1)) // expect: 1
+System.print((-1).clamp(0, 1)) // expect: 0
+System.print((-1).clamp(-20, 0)) // expect: -1
diff --git a/test/core/number/min_max.wren b/test/core/number/min_max.wren
@@ -0,0 +1,5 @@
+var num = 4
+var num2 = 6
+
+System.print(num.max(num2)) // expect: 6
+System.print(num.min(num2)) // expect: 4