nwsIFind-methods: Iterate Through Stored Values of a netWorkSpace Variable

In nws: R functions for NetWorkSpaces and Sleigh

Description

Create a function that acts as a non-destructive iterator over the values of the specified variable.

Usage

## S4 method for signature 'netWorkSpace'
nwsIFind(.Object, xName)

Arguments

.Object	a netWorkSpace class object.
xName	character string specifying the name of the variable to be fetched.

Details

The iterator function returned by the nwsIFind method takes no arguments, and works somewhat like the nwsFind method, specified with the same arguments that were passed to nwsIFind. The difference is that the nwsFind method cannot iterate through the values of a variable; it always returns the same value until the variable is modified. The iterator function, however, maintains some state that allows it to see subsequent values. Each time the iterator function is called, it returns the next value in the variable. Once all values in the variable have been returned, the iterator function blocks, waiting for a new value to be stored in the variable.

See Also

nwsFind, nwsIFindTry

Examples

## Not run: 
ws <- netWorkSpace('nws example')
nwsStore(ws, 'x', 1)
nwsStore(ws, 'x', 2)
it <- nwsIFind(ws, 'x')
it()  # returns the value 1
it()  # returns the value 2
it()  # blocks until another process stores a value in the variable

## End(Not run)

nws documentation built on May 2, 2019, 8:51 a.m.