regex capture repeated phrases

Question

I can capture repeated words pretty easily using: `"(?i)\b(\w+)(((\.{3}\s*|,\s+)*|\s+)\1)+\b"` but this regex does not seem to extend to mutipe words (and why should it in its current state). How could I find repeated phrases using regex? Here I extract repeated terms (regardless of case) but the same regex doesn't word to extract a repeated phrase: ``` library(qdapRegex) rm_default("this is a big Big deal", pattern = "(?i)\b(\w+)(((\.{3}\s*|,\s+)*|\s+)\1)+\b", extract=TRUE) rm_default("this is a big is a Big deal", pattern = "(?i)\b(\w+)(((\.{3}\s*|,\s+)*|\s+)\1)+\b", extract=TRUE) ``` I would hope for a regex that would return: ``` "is a big is a Big" ``` for: ``` x <- "this is a big is a Big deal" ``` To cover corner cases here's a larger desired test and output... ``` "this is a big is a Big deal", "I want want to see", "I want, want to see", "I want...want to see see how", "this is a big is a Big deal for those of, those of you who are.", "I like it. It is…

Accepted Answer

I think this does what you want (note we only allow a single space, `...`, or `,` as separators, but you should be able to tweak that easily):

```
pattern <- "(?i)\b(\w.*)((?:\s|\.{3}|,)+\1)+\b"
rm_default(x, pattern = pattern, extract=TRUE)
```

Produces:

```
[[1]]
[1] "is a big is a Big"

[[2]]
[1] "want want"

[[3]]
[1] "want, want"

[[4]]
[1] "want...want" "see see"

[[5]]
[1] "is a big is a Big"  "those of, those of"
```

regex capture repeated phrases

Solution

Problem