Category talk:Wren-math: Difference between revisions

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     static mod(x, y) { ((x % y) + y) % y }
-    // Returns whether or not 'n' is a perfect square.
+    // Returns the integer square root of 'x' or null if 'x' is negative.
-    static isSquare(n) {
+    static sqrt(x) { (x >= 0) ? x.sqrt.floor : null }
-        var s = n.sqrt.floor
-        return s * s == n
-    }
-    // Returns whether or not 'n' is a perfect cube.
+    // Returns the integer cube root of 'x'.
-    static isCube(n) {
+    static cbrt(x) { x.cbrt.truncate }
-        var c = n.cbrt.truncate
+    // Returns the integer 'n'th root of 'x' or null if 'x' is negative and 'n' is even.
-        return c * c * c == n
+    static root(n, x) {
+        if (!(n is Num) || !n.isInteger || n < 1) {
+            Fiber.abort("n must be a positive integer.")
+        }
+        return (n == 1) ? x :
+               (n == 2) ? sqrt(x) :
+               (n == 3) ? cbrt(x) :
+               (n % 2 == 1) ? x.sign * x.abs.pow(1/n).floor :
+               (n >= 0) ? x.pow(1/n).floor : null
+    }
+    // Returns whether or not 'x' is a perfect square.
+    static isSquare(x) {
+        var s = sqrt(x)
+        return s * s == x
+    }
+    // Returns whether or not 'x' is a perfect cube.
+    static isCube(x) {
+        var c = cbrt(x)
+        return c * c * c == x
+    }
+    // Returns whether or not 'x' is a perfect 'n'th power.
+    static isRoot(n, x) {
+        var r = root(n, x)
+        return r.pow(n) == x
     }