Make type checking non-strict by default

checker/checker.go

@@ -28,27 +28,25 @@ func Check(tree *parser.Tree, config *conf.Config) (t reflect.Type, err error) {
 		v.types = config.Types
 		v.operators = config.Operators
 		v.expect = config.Expect
-		v.strict = !config.AllowUndefinedVariables
-		v.defaultType = config.UndefinedVariableType
+		v.strict = config.Strict
+		v.defaultType = config.DefaultType
 	}
 
 	t = v.visit(tree.Node)
 
 	if v.expect != reflect.Invalid {
 		switch v.expect {
 		case reflect.Int64, reflect.Float64:
-			if isNumber(t) {
-				goto okay
+			if !isNumber(t) {
+				return nil, fmt.Errorf("expected %v, but got %v", v.expect, t)
 			}
 		default:
-			if t.Kind() == v.expect {
-				goto okay
+			if t.Kind() != v.expect {
+				return nil, fmt.Errorf("expected %v, but got %v", v.expect, t)
 			}
 		}
-		return nil, fmt.Errorf("expected %v, but got %v", v.expect, t)
 	}
 
-okay:
 	return
 }
 

cmd/exe/main.go

@@ -11,7 +11,6 @@ import (
 	"github.com/antonmedv/expr/ast"
 	"github.com/antonmedv/expr/checker"
 	"github.com/antonmedv/expr/compiler"
-	"github.com/antonmedv/expr/internal/conf"
 	"github.com/antonmedv/expr/optimizer"
 	"github.com/antonmedv/expr/parser"
 	"github.com/antonmedv/expr/vm"
@@ -88,9 +87,7 @@ func printAst() {
 	check(err)
 
 	if typeCheck {
-		_, err = checker.Check(tree, &conf.Config{
-			AllowUndefinedVariables: true,
-		})
+		_, err = checker.Check(tree, nil)
 		check(err)
 
 		if opt {

expr.go

@@ -50,10 +50,10 @@ func Env(i interface{}) Option {
 			c.MapEnv = true
 		} else {
 			if reflect.ValueOf(i).Kind() == reflect.Map {
-				c.UndefinedVariableType = reflect.TypeOf(i).Elem()
+				c.DefaultType = reflect.TypeOf(i).Elem()
 			}
 		}
-		c.CheckTypes = true
+		c.Strict = true
 		c.Types = conf.CreateTypesTable(i)
 	}
 }
@@ -64,8 +64,7 @@ func Env(i interface{}) Option {
 // runtime.fetch will panic as there is no way to get missing field zero value.
 func AllowUndefinedVariables() Option {
 	return func(c *conf.Config) {
-		c.CheckTypes = true
-		c.AllowUndefinedVariables = true
+		c.Strict = false
 	}
 }
 
@@ -124,13 +123,11 @@ func Compile(input string, ops ...Option) (*vm.Program, error) {
 		return nil, err
 	}
 
-	if config.CheckTypes {
-		_, err = checker.Check(tree, config)
-		if err != nil {
-			return nil, err
-		}
-		checker.PatchOperators(tree, config)
+	_, err = checker.Check(tree, config)
+	if err != nil {
+		return nil, err
 	}
+	checker.PatchOperators(tree, config)
 
 	if config.Optimize {
 		optimizer.Optimize(&tree.Node)