tag

The tag driver takes values right from the struct tags. It is used for default values.

import "github.com/insei/tinyconf/drivers/tag"

tagDriver, err := tag.New("initial")

The argument is the name of the tag with values, any name can be used: initial, default.

type Config struct {
    Host    string        `initial:"localhost"`
    Port    int           `initial:"8080"`
    Timeout time.Duration `initial:"30s"`
    Hosts   []string      `initial:"a,b"`
}

Add it first, so all other drivers can override the defaults:

config, err := tinyconf.New(
    tinyconf.WithDriver(tagDriver),
    tinyconf.WithDriver(yamlDriver),
    tinyconf.WithDriver(envDriver),
)

Values are parsed by the rules of string values. An incorrect default value is an error of Parse, so a typo in the tag is found at the first start.

The driver has no own documentation format, GenDoc returns an empty string for it. Default values are visible in the documentation of other drivers as the values of the fields.