The backend library

The backend library is used to manipulate nodes.

Keywords (TODO): line breaking, hpack, vpack, scaled points, text shaping, logging

Concepts

  • Glue x

  • Lengths, basic length is scaled points

  • Faces, fonts

stretchableglue

Bookmarks

Nodes

The PDF backend library

Logging

boxes and glue users the ZAP (sugared) logger. By default, it outputs JSON lines. To change that to something more readable, you can use the following function:

func newLogger(verbose bool) (*zap.SugaredLogger, error) {
	cfg := zap.Config{
		Encoding:    "console",
		OutputPaths: []string{"stdout"},
		EncoderConfig: zapcore.EncoderConfig{
			EncodeLevel: zapcore.LowercaseColorLevelEncoder,
			LevelKey:    "level",
			MessageKey:  "message",
		},
	}
	if verbose {
		cfg.Level = zap.NewAtomicLevelAt(zapcore.DebugLevel)
	} else {
		cfg.Level = zap.NewAtomicLevelAt(zapcore.InfoLevel)
	}
	logger, err := cfg.Build()
	if err != nil {
		return nil, err
	}
	return logger.Sugar(), nil
}

and call it like

if bag.Logger, err = newLogger(true); err != nil {
	return err
}