As long as you ask your configuration language to infer the data type from a piece of text, these are the kinds of edge cases you get to experience. (They vary by language. Less types means less mistakes, and so does less expressive power - but without some form of type hinting, that's where you are)
Personally, I like YAML for expressive simplicity at the start of a project, and then if it becomes an actual load bearing piece of software (vs a haphazard one off, or an experiment), let's add some schema validation & typing.
As long as you ask your configuration language to infer the data type from a piece of text, these are the kinds of edge cases you get to experience. (They vary by language. Less types means less mistakes, and so does less expressive power - but without some form of type hinting, that's where you are)
Personally, I like YAML for expressive simplicity at the start of a project, and then if it becomes an actual load bearing piece of software (vs a haphazard one off, or an experiment), let's add some schema validation & typing.