R: Lazy Load a Database of R Objects

lazyLoad {base} | R Documentation

## Lazy Load a Database of R Objects

### Description

Internal functions to lazy load a database of R objects.

### Usage

    lazyLoad(filebase, envir = parent.frame(), filter)
    lazyLoadDBexec(filebase, fun, filter)

### Arguments

`filebase` | The file path to the database, with no extension.
`envir` | The environment into which objects are loaded.
`filter` | An optional function which when called on a a character vector of object names returns a logical vector: only objects for which this is true will be loaded.
`fun` | Function of one argument, an environment.

### Details

These are internal functions for use only by R itself.

The function `lazyLoad` is the workhorse function called by the package loader to load the code for a package from a database. The database consists of two binary files, ‘filebase.rdb’ (the objects) and ‘filebase.rdx’ (an index).

The objects are not themselves loaded into `envir`: rather promises are created that will load the object from the database on first access. (See `delayedAssign`.)

The function `lazyLoadDBexec` contains the core implementation and is also used by the mechanism for loading processed help file data.

### Author(s)

Luke Tierney

[Package base version 3.5.1 Index]