Improve types pkg (#668)

Author: antonmedv

checker/checker_test.go

@@ -1074,7 +1074,7 @@ func TestCheck_types(t *testing.T) {
 	env := types.Map{
 		"foo": types.StrictMap{
 			"bar": types.Map{
-				"baz": "",
+				"baz": types.String,
 			},
 		},
 	}

checker/nature/of.go

@@ -7,7 +7,6 @@ import (
 	"github.com/expr-lang/expr/ast"
 	"github.com/expr-lang/expr/builtin"
 	"github.com/expr-lang/expr/checker/nature"
-	"github.com/expr-lang/expr/types"
 	"github.com/expr-lang/expr/vm/runtime"
 )
 
@@ -53,11 +52,7 @@ func New(env any) *Config {
 func (c *Config) WithEnv(env any) {
 	c.Strict = true
 	c.EnvObject = env
-	c.Env = nature.Of(env)
-	c.Env.Strict = true // To keep backward compatibility with expr.AllowUndefinedVariables()
-	if _, ok := env.(types.Map); ok {
-		c.Env.Strict = false
-	}
+	c.Env = Env(env)
 }
 
 func (c *Config) ConstExpr(name string) {

conf/config.go

@@ -0,0 +1,73 @@
+package conf
+
+import (
+	"fmt"
+	"reflect"
+
+	. "github.com/expr-lang/expr/checker/nature"
+	"github.com/expr-lang/expr/internal/deref"
+	"github.com/expr-lang/expr/types"
+)
+
+func Env(env any) Nature {
+	if env == nil {
+		return Nature{
+			Type:   reflect.TypeOf(map[string]any{}),
+			Strict: true,
+		}
+	}
+
+	switch env := env.(type) {
+	case types.Map:
+		return env.Nature()
+
+	case types.StrictMap:
+		return env.Nature()
+	}
+
+	v := reflect.ValueOf(env)
+	d := deref.Value(v)
+
+	switch d.Kind() {
+	case reflect.Struct:
+		return Nature{
+			Type:   v.Type(),
+			Strict: true,
+		}
+
+	case reflect.Map:
+		n := Nature{
+			Type:   v.Type(),
+			Fields: make(map[string]Nature, v.Len()),
+		}
+
+		for _, key := range v.MapKeys() {
+			elem := v.MapIndex(key)
+			if !elem.IsValid() || !elem.CanInterface() {
+				panic(fmt.Sprintf("invalid map value: %s", key))
+			}
+
+			face := elem.Interface()
+
+			switch face.(type) {
+			case types.Map:
+				n.Fields[key.String()] = face.(types.Map).Nature()
+
+			case types.StrictMap:
+				n.Fields[key.String()] = face.(types.StrictMap).Nature()
+
+			default:
+				if face == nil {
+					n.Fields[key.String()] = Nature{Nil: true}
+					continue
+				}
+				n.Fields[key.String()] = Nature{Type: reflect.TypeOf(face)}
+			}
+
+		}
+
+		return n
+	}
+
+	panic(fmt.Sprintf("unknown type %T", env))
+}

conf/env.go

@@ -6,6 +6,7 @@ import (
 	"strings"
 
 	"github.com/expr-lang/expr/checker/nature"
+	"github.com/expr-lang/expr/conf"
 	"github.com/expr-lang/expr/internal/deref"
 )
 
@@ -84,7 +85,7 @@ func CreateDoc(i any) *Context {
 		PkgPath:   deref.Type(reflect.TypeOf(i)).PkgPath(),
 	}
 
-	for name, t := range nature.Of(i).All() {
+	for name, t := range conf.Env(i).All() {
 		if _, ok := c.Variables[Identifier(name)]; ok {
 			continue
 		}

docgen/docgen.go

@@ -2705,7 +2705,7 @@ func TestExpr_nil_op_str(t *testing.T) {
 func TestExpr_env_types_map(t *testing.T) {
 	envTypes := types.Map{
 		"foo": types.StrictMap{
-			"bar": "value",
+			"bar": types.String,
 		},
 	}
 
@@ -2726,7 +2726,7 @@ func TestExpr_env_types_map(t *testing.T) {
 func TestExpr_env_types_map_error(t *testing.T) {
 	envTypes := types.Map{
 		"foo": types.StrictMap{
-			"bar": "value",
+			"bar": types.String,
 		},
 	}
 

expr_test.go

@@ -1,5 +1,74 @@
 package types
 
-type Map map[string]any
+import (
+	"reflect"
 
-type StrictMap map[string]any
+	. "github.com/expr-lang/expr/checker/nature"
+)
+
+func TypeOf(v any) Type {
+	return rtype{t: reflect.TypeOf(v)}
+}
+
+var (
+	Int     = TypeOf(0)
+	Int8    = TypeOf(int8(0))
+	Int16   = TypeOf(int16(0))
+	Int32   = TypeOf(int32(0))
+	Int64   = TypeOf(int64(0))
+	Uint    = TypeOf(uint(0))
+	Uint8   = TypeOf(uint8(0))
+	Uint16  = TypeOf(uint16(0))
+	Uint32  = TypeOf(uint32(0))
+	Uint64  = TypeOf(uint64(0))
+	Float   = TypeOf(float32(0))
+	Float64 = TypeOf(float64(0))
+	String  = TypeOf("")
+	Bool    = TypeOf(true)
+	Nil     = nilType{}
+)
+
+type Type interface {
+	Nature() Nature
+}
+
+type nilType struct{}
+
+func (nilType) Nature() Nature {
+	return Nature{Nil: true}
+}
+
+type rtype struct {
+	t reflect.Type
+}
+
+func (r rtype) Nature() Nature {
+	return Nature{Type: r.t}
+}
+
+type Map map[string]Type
+
+func (m Map) Nature() Nature {
+	nt := Nature{
+		Type:   reflect.TypeOf(map[string]any{}),
+		Fields: make(map[string]Nature, len(m)),
+	}
+	for k, v := range m {
+		nt.Fields[k] = v.Nature()
+	}
+	return nt
+}
+
+type StrictMap map[string]Type
+
+func (m StrictMap) Nature() Nature {
+	nt := Nature{
+		Type:   reflect.TypeOf(map[string]any{}),
+		Fields: make(map[string]Nature, len(m)),
+		Strict: true,
+	}
+	for k, v := range m {
+		nt.Fields[k] = v.Nature()
+	}
+	return nt
+}