ffdhall/ffdhall.go

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1.8 KiB
Go
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package ffdhall
import (
"errors"
"fmt"
"io"
"strings"
"github.com/philandstuff/dhall-golang/v6"
)
// DhallParser is a helper function that uses a default DhallParseConfig.
func DhallParser(r io.Reader, set func(name, value string) error) error {
return (&DhallParseConfig{}).Parse(r, set)
}
// DhallParseConfig collects parameters for the Dhall config file parser.
type DhallParseConfig struct {
// Delimiter is used when concatenating nested node keys into a flag name.
// The default delimiter is ".".
Delimiter string
}
// Parse a Dhall document from the provided io.Reader, using the provided set
// function to set flag values. Flag names are derived from the node names and
// their key/value pairs.
func (pc *DhallParseConfig) Parse(r io.Reader, set func(name, value string) error) error {
if pc.Delimiter == "" {
pc.Delimiter = "."
}
data, err := io.ReadAll(r)
if err != nil {
return err
}
// Compatibility with other parsers
if strings.TrimSpace(string(data)) == "" {
return nil
}
var m interface{}
if err := dhall.Unmarshal(data, &m); err != nil {
return DhallParseError{Inner: err}
}
mm, ok := m.(map[string]interface{})
if !ok {
return errors.New("could not unmarshal to map[string]interface{}")
}
if err := traverseMap(mm, pc.Delimiter, set); err != nil {
return DhallParseError{Inner: err}
}
return nil
}
// DhallParseError wraps all errors originating from the DhallParser.
type DhallParseError struct {
Inner error
}
// Error implenents the error interface.
func (e DhallParseError) Error() string {
return fmt.Sprintf("could not parse Dhall config: %v", e.Inner)
}
// Unwrap implements the errors.Wrapper interface, allowing errors.Is and
// errors.As to work with DhallParseErrors.
func (e DhallParseError) Unwrap() error {
return e.Inner
}