Regex to match a pattern but not two specific cases

Question

I want to match every cases of "-", but not these ones:

[\d]-[A-Z]
[A-Z]-[\d]

I tried this pattern: ((?<![A-Z])-(?![0-9]))|((?<![0-9])-(?![A-Z])) but some results are incorrect like: "RUA VF-32 N"

Can anyone help me?

what if their data has something like the word "sub-optimal"? Not that they'd want to remove the - there, but based on their requirements it seems like they would. — emsimpson92, Jul 27 '18 at 20:19
What language/library/tool are you using? What results are you getting and how are they incorrect (what did you expect instead)? — melpomene, Jul 27 '18 at 20:34
I'm using R. I wanted to match cases like "QUADRA 120 - ASA BRANCA" and "FAZENDA LAGE -RODOVIA RIO VERDE", but not "C-15" ou "99-B". "VF-32" is incorrect because "F-3" should not match. — Danilo, Jul 27 '18 at 20:42
Wiktor, the problem is that it will not match cases like "A-A", that is are necessary. — Danilo, Jul 27 '18 at 20:58

Wiktor Stribiżew · Accepted Answer · 2018-07-30T06:41:54.767

A simple approach is to use grep with your current logic and inverting the result, and then run another grep to only keep those items that have a hyphen in them:

x <- c("QUADRA 120 - ASA BRANCA","FAZENDA LAGE -RODOVIA RIO VERDE","C-15","99-B","A-A")
grep("-", grep("[A-Z]-\\d|\\d-[A-Z]", x, invert=TRUE, value=TRUE), value=TRUE, fixed=TRUE)
# => [1] "QUADRA 120 - ASA BRANCA"         "FAZENDA LAGE -RODOVIA RIO VERDE"
#    [3] "A-A"

Here, [A-Z]-\\d|\\d-[A-Z] matches a hyphen either in between an uppercase ASCII etter or a digit or betweena digit and an ASCII uppercase letter. If there is a match, the result is inverted due to invert=TRUE.

See the R demo.

To only match - in all contexts other than in between a letter and a digit, you may use the PCRE regex based on SKIP-FAIL technique like

> grep("(?:\\d-[A-Z]|[A-Z]-\\d)(*SKIP)(*F)|-", x, perl=TRUE)
[1] 1 2

See this regex demo

Details

(?:\d-[A-Z]|[A-Z]-\d) - a non-capturing group that matches either a digit, - and then uppercase ASCII letter, or an uppercase ASCII letter, - and a digit
(*SKIP)(*F) - omit the current match and proceed looking for the next match at the end of the "failed" match
| - or
- - a hyphen.

Regex to match a pattern but not two specific cases

1 Answers1