Extra type hints for maps content? about expr HOT 3 CLOSED

program, err := expr.Compile(code, expr.Env(map[string]interface{}{
    "A": int(0),
}))

package main

import (
	"fmt"

	"github.com/expr-lang/expr"
)

func main() {
	types := map[string]any{
		"foo": struct {
			Bar string `expr:"bar"`
		}{},
	}

	code := `foo.bar`

	// Do a type checks, and throw away compiled program. Turn off optimizations as we don't need those anmy way.
	// If compile program used, it will result in a error like this:
	//
	//  panic: reflect: call of reflect.Value.Field on map Value (1:5)
	//  | foo.bar
	//  | ....^
	//
	// As we expected a struct, but real env got a map.

	_, err := expr.Compile(code, expr.Env(types), expr.Optimize(false))
	if err != nil {
		panic(err)
	}

	env := map[string]any{
		"foo": map[string]any{
			"bar": "str",
		},
	}
	// After we type checked our code, we can run the code with actual env.
	output, err := expr.Eval(code, env)
	if err != nil {
		panic(err)
	}

	fmt.Println(output)
}