Add tasks for all the new languages

Task/Arithmetic-evaluation/Sidef/arithmetic-evaluation-1.sidef

@@ -0,0 +1,56 @@
+func evalArithmeticExp(s) {
+
+    func evalExp(s) {
+
+        func operate(s, op) {
+           s.split(op).map{|c| c.to_num }.reduce(op);
+        }
+
+        func add(s) {
+            operate(s.sub(/^\+/,'').sub(/\++/,'+'), '+');
+        }
+
+        func subtract(s) {
+            s.gsub!(/(\+-|-\+)/,'-');
+
+            if (s ~~ /--/) {
+                return(add(s.sub(/--/,'+')));
+            }
+
+            var b = s.split('-');
+            b.len == 3 ? (-1*b[1].to_num - b[2].to_num)
+                       : operate(s, '-');
+        }
+
+        s.gsub!(/[()]/,'').gsub!(/-\+/, '-');
+
+        var reM  = /\*/;
+        var reMD = %r"(\d+\.?\d*\s*[*/]\s*[+-]?\d+\.?\d*)";
+
+        var reA  = /\d\+/;
+        var reAS = /(-?\d+\.?\d*\s*[+-]\s*[+-]?\d+\.?\d*)/;
+
+        while (var match = reMD.match(s)) {
+            match[0] ~~ reM
+                ? s.sub!(reMD, operate(match[0], '*').to_s)
+                : s.sub!(reMD, operate(match[0], '/').to_s);
+        }
+
+        while (var match = reAS.match(s)) {
+            match[0] ~~ reA
+                ? s.sub!(reAS,      add(match[0]).to_s)
+                : s.sub!(reAS, subtract(match[0]).to_s);
+        }
+
+        return s;
+    }
+
+    var rePara = /(\([^\(\)]*\))/;
+    s.split!.join!('').sub!(/^\+/,'');
+
+    while (var match = s.match(rePara)) {
+        s.sub!(rePara, evalExp(match[0]));
+    }
+
+    return evalExp(s).to_num;
+}

Task/Arithmetic-evaluation/Sidef/arithmetic-evaluation-2.sidef

@@ -0,0 +1,13 @@
+for expr,res in [
+     ['2+3'                                      =>        5],
+     ['-4-3'                                     =>       -7],
+     ['-+2+3/4'                                  =>    -1.25],
+     ['2*3-4'                                    =>        2],
+     ['2*(3+4)+2/4'                              => 2/4 + 14],
+     ['2*-3--4+-0.25'                            =>    -2.25],
+     ['2 * (3 + (4 * 5 + (6 * 7) * 8) - 9) * 10' =>     7000],
+] { 
+    var num = evalArithmeticExp(expr);
+    assert_eq(num, res);
+    "%-45s == %10g\n".printf(expr, num);
+}