The funtion `loadDataFrom` does not take care of Windows users since any of the conditions met and it returns an error.
The change looks for the runtime where it's running and then if the filePath contains a `\`
When assigning values to flags (also when interogatting via
`context.(Global)IsSet`.
For boolean flags, consider empty as `false`.
Using `syscall.Getenv` rather than `os.LookupEnv` in order to support
older Golang versions.
Previously, defaults specified as nested keys in a yaml file would not
be recognized, i.e. `top: \n bottom: key` would not be accessible using
the name `top.bottom`, but `top.bottom: key` would. These changes
support using nested keys by traversing the configuration tree if the
key name uses '.' as a delimiter.
* fix typo (yamlSourceLoader -> yamlSourceContext)
* fix function return type (NewYamlSourceFromFlagFunc)
Also fixed build tags to properly build on >=go1.2
Signed-off-by: Jesse Szwedko <jesse.szwedko@gmail.com>
