nws (version 1.7.0.1)

nwsFetchTry: Fetch a Value from a NetWorkSpace (Non-Blocking Version)

Description

Attempt to fetch a value associated with a variable from the shared netWorkSpace; a non-blocking version of nwsFetch.

Usage

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

Arguments

.Object

a netWorkSpace class object

xName

name of the variable to be fetched

defaultVal

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

Details

Look in the shared netWorkSpace for a value bound to xName. If found, remove a value associated with xName from the shared netWorkSpace. This operation is atomic. If there are multiple nwsFetch or nwsFetchTry requests for a given xName, any given value from the set of values associated with xName will be returned to just one requester.

If variable is not found, return immediately rather than block on the operation (as in the case of nwsFetch). If variable is not found, the value of argument defaultVal is returned. By default, defaultVal is NULL.

See Also

nwsDeclare, nwsFetch

Examples

## Not run: 
# ws <- netWorkSpace('nws example')
# # If variable 'x' is not found in the shared netWorkSpace,
# # return default value, NULL.
# nwsFetchTry(ws, 'x')
# # If variable 'x' is not found in the shared netWorkSpace, 
# # return 10.
# nwsFetchTry(ws, 'x', 10)
# ## End(Not run)