miller/pkg/transformers/latin1_to_utf8.go
2025-03-09 14:59:16 -04:00

118 lines
3 KiB
Go

package transformers
import (
"fmt"
"os"
"strings"
"github.com/johnkerl/miller/v6/pkg/cli"
"github.com/johnkerl/miller/v6/pkg/lib"
"github.com/johnkerl/miller/v6/pkg/mlrval"
"github.com/johnkerl/miller/v6/pkg/types"
)
// ----------------------------------------------------------------
const verbNameLatin1ToUTF8 = "latin1-to-utf8"
var Latin1ToUTF8Setup = TransformerSetup{
Verb: verbNameLatin1ToUTF8,
UsageFunc: transformerLatin1ToUTF8Usage,
ParseCLIFunc: transformerLatin1ToUTF8ParseCLI,
IgnoresInput: false,
}
func transformerLatin1ToUTF8Usage(
o *os.File,
) {
fmt.Fprintf(o, "Usage: %s %s, with no options.\n", "mlr", verbNameLatin1ToUTF8)
fmt.Fprintf(o, "Recursively converts record strings from Latin-1 to UTF-8.\n")
fmt.Fprintf(o, "For field-level control, please see the latin1_to_utf8 DSL function.\n")
fmt.Fprintf(o, "Options:\n")
fmt.Fprintf(o, "-h|--help Show this message.\n")
}
func transformerLatin1ToUTF8ParseCLI(
pargi *int,
argc int,
args []string,
_ *cli.TOptions,
doConstruct bool, // false for first pass of CLI-parse, true for second pass
) IRecordTransformer {
// Skip the verb name from the current spot in the mlr command line
argi := *pargi
argi++
for argi < argc /* variable increment: 1 or 2 depending on flag */ {
opt := args[argi]
if !strings.HasPrefix(opt, "-") {
break // No more flag options to process
}
if args[argi] == "--" {
break // All transformers must do this so main-flags can follow verb-flags
}
argi++
if opt == "-h" || opt == "--help" {
transformerLatin1ToUTF8Usage(os.Stdout)
os.Exit(0)
} else {
transformerLatin1ToUTF8Usage(os.Stderr)
os.Exit(1)
}
}
*pargi = argi
if !doConstruct { // All transformers must do this for main command-line parsing
return nil
}
transformer, err := NewTransformerLatin1ToUTF8()
if err != nil {
fmt.Fprintln(os.Stderr, err)
os.Exit(1)
}
return transformer
}
// ----------------------------------------------------------------
type TransformerLatin1ToUTF8 struct {
}
func NewTransformerLatin1ToUTF8() (*TransformerLatin1ToUTF8, error) {
tr := &TransformerLatin1ToUTF8{}
return tr, nil
}
// ----------------------------------------------------------------
func (tr *TransformerLatin1ToUTF8) Transform(
inrecAndContext *types.RecordAndContext,
outputRecordsAndContexts *types.List[*types.RecordAndContext],
inputDownstreamDoneChannel <-chan bool,
outputDownstreamDoneChannel chan<- bool,
) {
HandleDefaultDownstreamDone(inputDownstreamDoneChannel, outputDownstreamDoneChannel)
if !inrecAndContext.EndOfStream {
inrec := inrecAndContext.Record
for pe := inrec.Head; pe != nil; pe = pe.Next {
inval := pe.Value
if inval.IsString() {
output, err := lib.TryLatin1ToUTF8(pe.Value.String())
if err == nil {
pe.Value = mlrval.FromString(output)
} else {
pe.Value = mlrval.FromError(err)
}
}
}
outputRecordsAndContexts.PushBack(types.NewRecordAndContext(inrec, &inrecAndContext.Context))
} else { // end of record stream
outputRecordsAndContexts.PushBack(inrecAndContext)
}
}