add type casting helpers

Author: AvicennaJr

evaluator/type.go

@@ -0,0 +1,72 @@
+package evaluator
+
+import (
+	"strconv"
+
+	"github.com/NuruProgramming/Nuru/object"
+)
+
+func convertToInteger(obj object.Object) object.Object {
+	switch obj := obj.(type) {
+	case *object.Integer:
+		return obj
+	case *object.Float:
+		return &object.Integer{Value: int64(obj.Value)}
+	case *object.String:
+		i, err := strconv.ParseInt(obj.Value, 10, 64)
+		if err != nil {
+			return newError("Haiwezi kubadilisha '%s' kuwa NAMBA", obj.Value)
+		}
+		return &object.Integer{Value: i}
+	case *object.Boolean:
+		if obj.Value {
+			return &object.Integer{Value: 1}
+		}
+		return &object.Integer{Value: 0}
+	default:
+		return newError("Haiwezi kubadilisha %s kuwa NAMBA", obj.Type())
+	}
+}
+
+func convertToFloat(obj object.Object) object.Object {
+	switch obj := obj.(type) {
+	case *object.Float:
+		return obj
+	case *object.Integer:
+		return &object.Float{Value: float64(obj.Value)}
+	case *object.String:
+		f, err := strconv.ParseFloat(obj.Value, 64)
+		if err != nil {
+			return newError("Haiwezi kubadilisha '%s' kuwa DESIMALI", obj.Value)
+		}
+		return &object.Float{Value: f}
+	case *object.Boolean:
+		if obj.Value {
+			return &object.Float{Value: 1.0}
+		}
+		return &object.Float{Value: 0.0}
+	default:
+		return newError("Haiwezi kubadilisha %s kuwa DESIMALI", obj.Type())
+	}
+}
+
+func convertToString(obj object.Object) object.Object {
+	return &object.String{Value: obj.Inspect()}
+}
+
+func convertToBoolean(obj object.Object) object.Object {
+	switch obj := obj.(type) {
+	case *object.Boolean:
+		return obj
+	case *object.Integer:
+		return &object.Boolean{Value: obj.Value != 0}
+	case *object.Float:
+		return &object.Boolean{Value: obj.Value != 0}
+	case *object.String:
+		return &object.Boolean{Value: len(obj.Value) > 0}
+	case *object.Null:
+		return &object.Boolean{Value: false}
+	default:
+		return &object.Boolean{Value: true}
+	}
+}