---
name: "Statistics::R::IO::REXPFactory"
section: "3pm"
platform: "linux"
package: "libstatistics-r-io-perl"
version: "1.0002-2"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/Statistics::R::IO::REXPFactory"
---

# Statistics::R::IO::REXPFactory(3pm)

Functions for parsing R data files

## NAME

Statistics::R::IO::REXPFactory - Functions for parsing R data files

## VERSION

version 1.0002

## SYNOPSIS

```
    use Statistics::R::IO::REXPFactory qw( unserialize );
    # Assume $data was created by reading, say, an RDS file
    my ($rexp, $state) = @{unserialize($data)}
        or die "couldn't parse";

    # If we're reading an RDS file, there should be no data left
    # unparsed
    die 'Unread data remaining in the RDS file' unless $state->eof;
    # the result of the unserialization is a REXP
    say $rexp;
    # REXPs can be converted to the closest native Perl data type
    print $rexp->to_pl;
```

## DESCRIPTION

This module implements the actual reading of serialized R objects and their conversion to a Statistics::R::REXP. You are not expected to use it directly, as it's normally wrapped by "readRDS" in Statistics::R::IO and "readRData" in Statistics::R::IO.

## SUBROUTINES

- unserialize $data

  Constructs a Statistics::R::REXP object from its serialization in `$data`. Returns a pair of the object and the Statistics::R::IO::ParserState at the end of serialization.

- intsxp, langsxp, lglsxp, listsxp, rawsxp, realsxp, refsxp, strsxp, symsxp, vecsxp, envsxp, charsxp, cplxsxp, closxp, expsxp, s4sxp

  Parsers for the corresponding R SEXP-types.

- object\_content

  Parses object info and its data by sequencing "unpack\_object\_info" and "object\_data".

- unpack\_object\_info

  Parser for serialized object info structure. Returns a hash with keys "is\_object", "has\_attributes", "has\_tag", "object\_type", and "levels", each corresponding to the field in R serialization described in \<http://cran.r-project.org/doc/manuals/r-release/R-ints.html#Serialization-Formats\>. An additional key "flags" contains the full 32-bit value as stored in the file.

- object\_data $obj\_info

  Parser for a serialized R object, using the object type stored in `$obj_info` hash's "object\_type" key to use the correct parser for the particular type.

- vector\_and\_attributes $object\_info, $element\_parser, $rexp\_class

  Convenience parser for vectors, which are serialized first with a SEXP for the vector elements, followed by attributes stored as a tagged pairlist. Attributes are stored only if `$object_info` indicates their presence, while vector elements are parsed using `$element_parser`. Finally, the parsed attributes and elements are used as arguments to the constructor of the `$rexp_class`, which should be a subclass of Statistics::R::REXP::Vector.

- header

  Parser for header of R serialization: the serialization format (XDR, binary, etc.), the version number of the serialization (currently 2), and two 32-bit integers indicating the version of R which wrote the file followed by the minimal version of R needed to read the format.

- xdr, bin

  Parsers for RDS header indicating files in XDR or native-binary format.

- maybe\_long\_length

  Parser for vector length, allowing for the encoding of 64-bit long vectors introduced in R 3.0.

- tagged\_pairlist\_to\_rexp\_hash

  Converts a pairlist to a REXP hash whose keys are the pairlist's element tags and values the pairlist elements themselves.

- tagged\_pairlist\_to\_attribute\_hash

  Converts object attributes, which are serialized as a pairlist with attribute name in the element's tag, to a hash that can be used as the `"attributes"` argument to Statistics::R::REXP constructors.

  Some attributes are serialized using a compact encoding (for instance, when a table's row names are just integers 1:nrows), and this function will decode them to a complete REXP.

## BUGS AND LIMITATIONS

There are no known bugs in this module. Please see Statistics::R::IO for bug reporting.

## SUPPORT

See Statistics::R::IO for support and contact information.

## AUTHOR

Davor Cubranic \<cubranic@stat.ubc.ca\>

## COPYRIGHT AND LICENSE

This software is Copyright (c) 2017 by University of British Columbia.

This is free software, licensed under:

```
  The GNU General Public License, Version 3, June 2007
```