R: Abbreviate state names in strings - regex

Question

I have strings with state names in them. How do I efficiently abbreviate them? I am aware of state.abb[grep("New York", state.name)] but this works only if "New York" is the whole string. I have, for example, "Walmart, New York". Thanks in advance!
Let's assume this input:
x = c("Walmart, New York", "Hobby Lobby (California)", "Sold in Sears in Illinois")
Edit: desired outputs will be a la "Walmart, NY", "Hobby Lobby (CA)", "Sold in Sears in IL". As you can see from here, state can appear in many ways in a string

Answer 1

Here's a base R way, using gregexpr(), regmatches(), and regmatches<-(), :
abbreviateStateNames <- function(x) {
pat <- paste(state.name, collapse="|")
m <- gregexpr(pat, x)
ff <- function(x) state.abb[match(x, state.name)]
regmatches(x, m) <- lapply(regmatches(x, m), ff)
x
}
x <- c("Hobby Lobby (California)",
"Hello New York City, here I come (from Greensboro North Carolina)!")
abbreviateStateNames(x)
# [1] "Hobby Lobby (CA)"
# [2] "Hello NY City, here I come (from Greensboro NC)!"
Alternatively -- and quite a bit more naturally -- you can accomplish the same thing using the gsubfn package:
library(gsubfn)
pat <- paste(state.name, collapse="|")
gsubfn(pat, function(x) state.abb[match(x, state.name)], x)
[1] "Hobby Lobby (CA)"
[2] "Hello NY City, here I come (from Greensboro NC)!"