pofile is a Go module for gettext text catalogs: .po and .pot.

It is built for predictable file processing in build tools and localization pipelines, without pulling in runtime gettext behavior.

It provides:

• semantic parse API (Parse, ParseReader, ParseFile, ParseDir)
• lossless parse API (ParseDocument*) with source positions
• parser diagnostics (ParseCatalogWithDiagnostics)
• formatter/writer (Format, WriteFile, FormatDocument)
• semantic model (Catalog, Message)
• lossless model (Document, Entry, Comment, Header)
• index for fast key lookup in lossless model (NewIndex, EntryKey)
• lint/validation (LintDocumentWithOptions, ValidateDocument)
• merge helper (MergeTemplate)

Scope:

• text .po/.pot only
• no binary .mo
• no runtime gettext engine

go get github.com/woozymasta/pofile

package main

import (
    "log"

    "github.com/woozymasta/pofile"
)

func main() {
    catalog, err := pofile.ParseFile("l18n/russian.po")
    if err != nil {
        log.Fatal(err)
    }

    catalog.UpsertMessage("UI_OK", "OK", "Ок")
    catalog.SetHeader("Last-Translator", "team@example.com")

    if err := pofile.WriteFile("l18n/russian.po", catalog); err != nil {
        log.Fatal(err)
    }
}

catalog, diagnostics, err := pofile.ParseCatalogWithDiagnostics(
    data,
    pofile.ParseOptions{AllowInvalid: true},
)
if err != nil {
    return err
}
_ = catalog
for _, d := range diagnostics {
    // d.Code, d.Severity, d.Start, d.End
}

Machine-readable rules registry: rules.yaml
Human-readable rules reference: RULES.md