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regexdart
DomJack
DomJack

Reputation: 4183

Dart RegExp: single pass with multiple patterns?

If I search a string for matches to a regex which is the union of two or more sub-regexen, is there any way to determine which sub-regex matches without checking each of them individually?

For example, if I have the code:

var regExp = new RegExp('ab|cd');
var matches = regExp.allMatches('absolutely fabulous');

the search returns two matches - but is there a way for me to know which match corresponds to which sub-regex?

Upvotes: 1

Views: 2053

Answers (1)

DomJack
DomJack

Reputation: 4183

Found an answer thanks to searching for branches.

var regExp = new RegExp('(ab)|(cd)'); //brackets are significant
var matches = regExp.allMatches('absolutely fabulous');

var m1 = match.first;
print(m1.group(1)); // 'ab'
print(m1.group(2)); // null, since second term (cd) not matched here

var m2 = match.last;
print(m2.group(1)); // null, since first pattern not matched here
print(m2.group(2)): // 'ac'

Other useful info at dart regex matching and get some information from it

Upvotes: 3

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