IsErrInvalidEnvelope checks if an error is of ErrInvalidEnvelope type.

NewFixedLengthFileFormat creates a FileFormat for fixed-length files.

NewReader creates an FormatReader for fixed-length file format.

ByHeaderFooterDecl contains the header and footer regexp patterns for a `by_header_footer` envelope.

ColumnDecl describes fixed-length envelope column settings for omniparser reader.

EnvelopeDecl describes fixed-length envelope settings for omniparser reader.

FileDecl describes fixed-length specific schema settings for omniparser reader.

ErrInvalidEnvelope indicates a fixed-length input envelope is invalid.