Insert special character in R based on existing words - r

Question

I was looking for a intuitive solution for a problem of mine.
I have a huge list of words, in which i have to insert a special character based on some criteria.
So if a two/three letter word appear in a cell i want to add "+" right and left to it
Example
global b2b banking would transform to global +b2b+ banking
how to finance commercial ale estate would transform to how +to+ finance commercial +ale+ estate
Here is sample data set:
sample <- c("commercial funding",
"global b2b banking"
"how to finance commercial ale estate"
"opening a commercial account",
"international currency account",
"miami imports banking",
"hsbc supply chain financing",
"international business expansion",
"grow business in Us banking",
"commercial trade Asia Pacific",
"business line of credits hsbc",
"Britain commercial banking",
"fx settlement hsbc",
"W Hotels")
data <- data.frame(sample)
Additionally is it possible to drop a row which has a character of length 1 ?
Example:
W Hotels
For all the one letter word i tried removing them with gsub,
gsub(" *\\b[[:alpha:]]{1,1}\\b *", " ", sample)
This should be removed from the data set set.
Any help is highly appreciated.
Edit 1
Thanks for the help, I added few more lines to it:
sample <- c("commercial funding", "global b2b banking", "how to finance commercial ale estate", "opening a commercial account","international currency account","miami imports banking","hsbc supply chain financing","international business expansion","grow business in Us banking", "commercial trade Asia Pacific","business line of credits hsbc","Britain commercial banking","fx settlement hsbc", "W Hotels")
sample <- sample[!grepl("\\b[[:alpha:]]\\b",sample)]
sample <- gsub("\\b([[:alpha:][:digit:]]{2,3})\\b", "+\\1+", sample)
sample <- gsub(" ",",",sample)
sample <- gsub("+,","+",sample)
sample <- gsub(",+","+",sample)
sample <- tolower(sample)
sample <- ifelse(substr(sample, 1, 1) == "+", sub("^.", "", sample), sample)
data <- data.frame(sample)
data
sample
1 commercial++funding
2 global+++b2b+++banking
3 how++++to+++finance++commercial+++ale+++estate
4 international++currency++account
5 miami++imports++banking
6 hsbc++supply++chain++financing
7 international++business++expansion
8 grow++business+++in++++us+++banking
9 commercial++trade++asia++pacific
10 business++line+++of+++credits++hsbc
11 britain++commercial++banking
12 fx+++settlement++hsbc
Somehow i am unable to remove "+," with "," with gsub ? what am i doing wrong ?
so "fx+,settlement,hsbc" should be "fx+settlement,hsbc" but it is replacing , wth additional ++.

Answer 1

You need to do that in 2 steps: remove the items with 1-letter whole words, and then add + around 2-3 letter words.
Use
sample <- c("commercial funding", "global b2b banking", "how to finance commercial ale estate", "opening a commercial account","international currency account","miami imports banking","hsbc supply chain financing","international business expansion","grow business in Us banking", "commercial trade Asia Pacific","business line of credits hsbc","Britain commercial banking","fx settlement hsbc", "W Hotels")
sample <- sample[!grepl("\\b[[:alnum:]]\\b",sample)]
sample <- gsub("\\b([[:alnum:]]{2,3})\\b", "+\\1+", sample)
data <- data.frame(sample)
data
See the R demo
The sample[!grepl("\\b[[:alnum:]]\\b",sample)] removes the items that contain word boundary (\b), a letter ([[:alnum:]]) and a word boundary pattern.
The gsub("\\b([[:alnum:]]{2,3})\\b", "+\\1+", sample) line replaces all 2-3-letter whole words with these words enclosed with +.
Result:
sample
1 commercial funding
2 global +b2b+ banking
3 +how+ +to+ finance commercial +ale+ estate
4 international currency account
5 miami imports banking
6 hsbc supply chain financing
7 international business expansion
8 grow business +in+ +Us+ banking
9 commercial trade Asia Pacific
10 business line +of+ credits hsbc
11 Britain commercial banking
12 +fx+ settlement hsbc
Note that W Hotels and opening a commercial account got filtered out.
Answer to the EDIT
You added some more replacement operations to the code, but you are using literal string replacements, thus, you just need to pass fixed=TRUE argument:
sample <- gsub(" ",",",sample, fixed=TRUE)
sample <- gsub("+,","+",sample, fixed=TRUE)
sample <- gsub(",+","+",sample, fixed=TRUE)
Else, the + is treated as a regex quantifier, and must be escaped to be treated as a literal plus symbol.
Also, if you need to remove all + from the start of the string, use
sample <- sub("^\\++", "", sample)