registry-utils {GenomicFiles} | R Documentation

## Functions for creating and searching a registry of file types.

### Description

Functions for creating and searching a registry of file types based on file extension.

### Usage

      registerFileType(type, package, regex)
      findTypeRegistry(fnames)
      makeFileType(fnames, ..., regex=findTypeRegistry(fnames))

### Arguments

`type` | The List class the file is associated with such as BamFileList, BigWigFileList, FaFileList.
`package` | The package where the List class (`type`) is defined.
`regex` | A regular expression that uniquely identifies the file extension.
`fnames` | A `character` vector of file names.
`...` | Additional arguments passed to the List-class constructor (e.g., yieldSize for BamFileList).

### Details

- registerFileType The `registerFileType` function adds entries to the file type register created at load time. The point of the register is for discovery of file type (class) by file extension. These are List-type classes (e.g., BamFileList) that occupy the `fileList` slot of a GenomicFiles class.

  Each List class entry in the register is associated with (1) a regular expression that identifies the file extension, (2) a class and (3) the package where the class is defined. At load time the register is populated with classes known to GenomicFiles. New classes / file types can be added to the register with `registerFileType` by providing these three pieces of information.

- findTypeRegistry Searches the registry for a match to the extension of `fname`. Internal use only.

- makeFileType Performs a look-up in the file registry based on the supplied regular expression; returns an object of the associated class. Internal use only.

### Value

`registerFileType`: NULL

`findTypeRegistry`: The regular expression associated with the file.

`makeFileType`: A List-type object defined in the registry.

### Examples

    ## At load time the registry is populated with file types
    ## known to GenomicFiles.
    sapply(as.list(.fileTypeRegistry), "[", "type")

    ## Add a new class to the file register.
    ## Not run: registerFileType(NewClassList, NewPackage, "\.NewExtension$")

[Package GenomicFiles version 1.28.0 Index]