Data commit

Task/Extend-your-language/Wren/extend-your-language.wren

@@ -0,0 +1,52 @@
+class IfBoth {
+    construct new(cond1, cond2) {
+        _cond1 = cond1
+        _cond2 = cond2
+    }
+
+    elseFirst(func) {
+        if (_cond1 && !_cond2) func.call()
+        return this
+    }
+
+    elseSecond(func) {
+        if (_cond2 && !_cond1) func.call()
+        return this
+    }
+
+    elseNeither(func) {
+        if (!_cond1 && !_cond2) func.call()
+        return this // in case it's called out of order
+    }
+}
+
+var ifBoth = Fn.new { |cond1, cond2, func|
+    if (cond1 && cond2) func.call()
+    return IfBoth.new(cond1, cond2)
+}
+
+var a = 0
+var b = 1
+
+ifBoth.call(a == 1, b == 3) {
+    System.print("a == 1 and b == 3")
+}.elseFirst {
+    System.print("a == 1 and b <> 3")
+}.elseSecond {
+    System.print("a <> 1 and b = 3")
+}.elseNeither {
+    System.print("a <> 1 and b <> 3")
+}
+
+// It's also possible to omit any (or all) of the 'else' clauses
+// or to call them out of order.
+a = 1
+b = 0
+
+ifBoth.call (a == 1, b == 3) {
+    System.print("a == 1 and b == 3")
+}.elseNeither {
+    System.print("a <> 1 and b <> 3")
+}.elseFirst {
+    System.print("a == 1 and b <> 3")
+}