R Regex / gsub：如何折叠字符串中的空格

Question

I have a vector of sentences that were scanned from handwritten documents. In the process there were some spacing problems like this:

 The d og is br own.

I was curious if there was a way to generically take any pattern with '_x_' or space-character-space and collapse the second space like this:

The d og is br own.  --> The dog is br own.

I'm only worried about a single character between the spaces ( '_x_' NOT '_xx_' ).

Any suggestions?

Answer 1

Maybe

> x<-"The d og is br own."
> gsub(" (.) "," \\1",x)
[1] "The dog is br own."

or

gsub(" ([[:alnum:]]) "," \\1",x)

(.) matches anything ([[:alnum:]]) matches alphanumeric characters only.