转到AST /类型-如何判断错误？

Question

Is there a better way of doing this? I need to know if the type of v is the built-in "error" type. I feel like there should be a neater way of doing this:

import (
    "go/ast"
    "go/types"
)

func IsError(v ast.Expr, info types.Info) bool {
    t := info.Types[v]
    return t.Type.String() == "error" &&
        t.Type.Underlying().String() == "interface{Error() string}"
}

Answer 1

Type assertion is the idiomatic way of checking the type of a variable.

Given you're handling an AST expression, I'd try to check if the underlying type is an interface and if the Error() method is implemented:

isError := func(v ast.Expr, info *types.Info) bool {
    if intf, ok := info.TypeOf(v).Underlying().(*types.Interface); ok {
        return intf.NumMethods() == 1 && intf.Method(0).FullName() == "(error).Error"
    }
    return false
}