I have an ingredient dataset and each row is a list of ingredients that's separated by comma, for example:
Oats (24%) (Rolled, Bran), Coconut (13%) (Coconut , Preservative (220, 223)), Brown Sugar, Milk Solids, Golden Syrup (10%), Seeds (9%) (Sesame , Sunflower), Margarine (Vegetable Oil, Water, Salt, Emulsifiers (471, Soy Lecithin), Antioxidant (307)), Glucose, Milk Choc Compound (5%) (Sugar, Vegetable Oil, Milk Solids, Cocoa Powder, Emulsifiers (Soy Lecithin, 492), Natural Flavour), Natural Flavour
I want to parse the file to replace only commas within brackets with a semicolon. There can be any number of brackets and any number of commas within the brackets. The result should look like this:
Oats (24%) (Rolled;Bran), Coconut (13%) (Coconut ; Preservative (220; 223)), Brown Sugar, Milk Solids, Golden Syrup (10%), Seeds (9%) (Sesame ;Sunflower), Margarine (Vegetable Oil; Water; Salt; Emulsifiers (471; Soy Lecithin); Antioxidant (307)), Glucose, Milk Choc Compound (5%) (Sugar; Vegetable Oil; Milk Solids; Cocoa Powder; Emulsifiers (Soy Lecithin; 492); Natural Flavour), Natural Flavour
Can I get some help on regex that will solve the problem? Thank you in advance.
You can use ?R like.
i <- gregexpr("\\(([^()]|(?R))*\\)", s, perl=TRUE)
regmatches(s, i)[[1]] <- gsub(",", ";", regmatches(s, i)[[1]])
s
#[1] "Oats (24%) (Rolled; Bran), Coconut (13%) (Coconut ; Preservative (220; 223)), Brown Sugar, Milk Solids, Golden Syrup (10%), Seeds (9%) (Sesame ; Sunflower), Margarine (Vegetable Oil; Water; Salt; Emulsifiers (471; Soy Lecithin); Antioxidant (307)), Glucose, Milk Choc Compound (5%) (Sugar; Vegetable Oil; Milk Solids; Cocoa Powder; Emulsifiers (Soy Lecithin; 492); Natural Flavour), Natural Flavour"
Where a(?R)z is a recursion which match one or more letters a followed by exactly the same number of letters z.
Data
s <- "Oats (24%) (Rolled, Bran), Coconut (13%) (Coconut , Preservative (220, 223)), Brown Sugar, Milk Solids, Golden Syrup (10%), Seeds (9%) (Sesame , Sunflower), Margarine (Vegetable Oil, Water, Salt, Emulsifiers (471, Soy Lecithin), Antioxidant (307)), Glucose, Milk Choc Compound (5%) (Sugar, Vegetable Oil, Milk Solids, Cocoa Powder, Emulsifiers (Soy Lecithin, 492), Natural Flavour), Natural Flavour"