nws (version 1.7.0.1)

nwsIFetchTry: Iterate Through Values of a netWorkSpace Variable

Description

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

Usage

"nwsIFetchTry"(.Object, xName, defaultVal=NULL)

Arguments

.Object

a netWorkSpace class object.

xName

character string specifying name of the variable to be fetched.

defaultVal

value to return, if xName is not found in the netWorkSpace.

Details

The iterator function returned by the nwsIFetchTry method takes no arguments, and works just like the nwsFetchTry method, specified with the same arguments that were passed to nwsIFetchTry method. Note that the nwsIFind and nwsIFindTry methods are much more useful, since they provide the only way to iterate over values of a variable non-destructively. The nwsIFetch and nwsIFetchTry methods are provided for completeness.

See Also

nwsFetchTry, nwsIFetch

Examples

## Not run: 
# ws <- netWorkSpace('nws example')
# nwsStore(ws, 'x', 10)
# it <- nwsIFetchTry(ws, 'x', NA)
# it()  # returns the value 10
# it()  # returns NA
# ## End(Not run)