Xmisc (version 0.0.9)

valid.arg.index: Check validity of an index

Description

Check validity of an index of a list object.

Usage

valid.arg.index(obj, x, safe = TRUE)

Arguments

obj

list

x

index or name of an element

safe

whether safe if an index is higher than the one of any named element

Value

• numeric, the index. Return numeric(0) if the name or the index does not exist or when the index is invalid. If safe is FALSE, any index is valid; if safe is TRUE, an index is invalid when the indexed element is positionally after another named element.

Examples

ll <- list(11,12,13,a=14,b=15,16,17,c=18,19)
valid.arg.index(ll,-1) # non-existing index
valid.arg.index(ll,0)  # non-existing index
valid.arg.index(ll,1)  # valid index
valid.arg.index(ll,2)  # valid index
valid.arg.index(ll,5)  # invalid index
valid.arg.index(ll,10) # non-existing index
valid.arg.index(ll,"a")# valid name
valid.arg.index(ll,"e")# non-existing name
valid.arg.index(ll,5,safe=FALSE) # still return the index