chore: upgrade coredns version (#550)

vendor/github.com/expr-lang/expr/optimizer/optimizer.go

@@ -0,0 +1,79 @@
+package optimizer
+
+import (
+	"fmt"
+	"reflect"
+
+	. "github.com/expr-lang/expr/ast"
+	"github.com/expr-lang/expr/conf"
+)
+
+func Optimize(node *Node, config *conf.Config) error {
+	Walk(node, &inArray{})
+	for limit := 1000; limit >= 0; limit-- {
+		fold := &fold{}
+		Walk(node, fold)
+		if fold.err != nil {
+			return fold.err
+		}
+		if !fold.applied {
+			break
+		}
+	}
+	if config != nil && len(config.ConstFns) > 0 {
+		for limit := 100; limit >= 0; limit-- {
+			constExpr := &constExpr{
+				fns: config.ConstFns,
+			}
+			Walk(node, constExpr)
+			if constExpr.err != nil {
+				return constExpr.err
+			}
+			if !constExpr.applied {
+				break
+			}
+		}
+	}
+	Walk(node, &inRange{})
+	Walk(node, &filterMap{})
+	Walk(node, &filterLen{})
+	Walk(node, &filterLast{})
+	Walk(node, &filterFirst{})
+	Walk(node, &predicateCombination{})
+	Walk(node, &sumArray{})
+	Walk(node, &sumMap{})
+	return nil
+}
+
+var (
+	boolType    = reflect.TypeOf(true)
+	integerType = reflect.TypeOf(0)
+	floatType   = reflect.TypeOf(float64(0))
+	stringType  = reflect.TypeOf("")
+)
+
+func patchWithType(node *Node, newNode Node) {
+	switch n := newNode.(type) {
+	case *BoolNode:
+		newNode.SetType(boolType)
+	case *IntegerNode:
+		newNode.SetType(integerType)
+	case *FloatNode:
+		newNode.SetType(floatType)
+	case *StringNode:
+		newNode.SetType(stringType)
+	case *ConstantNode:
+		newNode.SetType(reflect.TypeOf(n.Value))
+	case *BinaryNode:
+		newNode.SetType(n.Type())
+	default:
+		panic(fmt.Sprintf("unknown type %T", newNode))
+	}
+	Patch(node, newNode)
+}
+
+func patchCopyType(node *Node, newNode Node) {
+	t := (*node).Type()
+	newNode.SetType(t)
+	Patch(node, newNode)
+}