Add ^ as exponent operator

Author: antonmedv

checker/checker.go

@@ -282,7 +282,7 @@ func (v *visitor) BinaryNode(node *ast.BinaryNode) (reflect.Type, info) {
 			return anyType, info{}
 		}
 
-	case "**":
+	case "**", "^":
 		if isNumber(l) && isNumber(r) {
 			return floatType, info{}
 		}

checker/checker_test.go

@@ -43,6 +43,7 @@ var successTests = []string{
 	"-1 + +1 == 0",
 	"1 / 2 == 0",
 	"2**3 + 1 != 0",
+	"2^3 + 1 != 0",
 	"Float == 1",
 	"Float < 1.0",
 	"Float <= 1.0",

compiler/compiler.go

@@ -385,7 +385,7 @@ func (c *compiler) BinaryNode(node *ast.BinaryNode) {
 		c.compile(node.Right)
 		c.emit(OpModulo)
 
-	case "**":
+	case "**", "^":
 		c.compile(node.Left)
 		c.compile(node.Right)
 		c.emit(OpExponent)

docs/Language-Definition.md

@@ -49,12 +49,12 @@ foo.Method()
 * `*` (multiplication)
 * `/` (division)
 * `%` (modulus)
-* `**` (pow)
+* `^` or `**` (exponent)
 
 Example:
 
 ```
-x**2 + y
+x^2 + y^2
 ``` 
 
 ### Comparison Operators

expr_test.go

@@ -619,6 +619,10 @@ func TestExpr(t *testing.T) {
 			`2 ** 8`,
 			float64(256),
 		},
+		{
+			`2 ^ 8`,
+			float64(256),
+		},
 		{
 			`-(2-5)**3-2/(+4-3)+-2`,
 			float64(23),

optimizer/fold.go

@@ -89,7 +89,7 @@ func (fold *fold) Visit(node *Node) {
 					patch(&IntegerNode{Value: a.Value % b.Value})
 				}
 			}
-		case "**":
+		case "**", "^":
 			if a, ok := n.Left.(*IntegerNode); ok {
 				if b, ok := n.Right.(*IntegerNode); ok {
 					patch(&FloatNode{Value: math.Pow(float64(a.Value), float64(b.Value))})

parser/lexer/state.go

@@ -30,7 +30,7 @@ func root(l *lexer) stateFn {
 		l.emit(Bracket)
 	case strings.ContainsRune(")]}", r):
 		l.emit(Bracket)
-	case strings.ContainsRune("#,?:%+-/", r): // single rune operator
+	case strings.ContainsRune("#,?:%+-/^", r): // single rune operator
 		l.emit(Operator)
 	case strings.ContainsRune("&|!=*<>", r): // possible double rune operator
 		l.accept("&|=*")

parser/parser.go

@@ -59,6 +59,7 @@ var binaryOperators = map[string]operator{
 	"/":          {60, left},
 	"%":          {60, left},
 	"**":         {100, right},
+	"^":          {100, right},
 }
 
 var builtins = map[string]builtin{

parser/parser_test.go

@@ -60,11 +60,11 @@ func TestParse(t *testing.T) {
 			&ast.UnaryNode{Operator: "-", Node: &ast.IntegerNode{Value: 3}},
 		},
 		{
-			"-2**2",
+			"-2^2",
 			&ast.UnaryNode{
 				Operator: "-",
 				Node: &ast.BinaryNode{
-					Operator: "**",
+					Operator: "^",
 					Left:     &ast.IntegerNode{Value: 2},
 					Right:    &ast.IntegerNode{Value: 2},
 				},