Return capturing names for a pre-compiled regular expression.

Usage

get_named_groups(pattern, ...)

Arguments

pattern

a pre-compiled regular expression or a string

...

further arguments passed to re2

Examples

get_named_groups(re2("(a)(?P<name>b)"))

[1] ".match" ".1"     "name"  


regexp = re2("(?P<A>exprA(?P<B>exprB)(?P<C>exprC))((expr5)(?P<D>exprD))")

print(regexp)

re2 pre-compiled regular expression

pattern: (?P<A>exprA(?P<B>exprB)(?P<C>exprC))((expr5)(?P<D>exprD))
number of capturing subpatterns: 6
capturing names with indices: 
.match A B C .4 .5 D
expression size: 41

(res = get_named_groups(regexp))

[1] ".match" "A"      "B"      "C"      ".4"     ".5"     "D"     

re2_match("exprAexprBexprCexpr5exprD", regexp)

     .match                      A                 B       C       .4          
[1,] "exprAexprBexprCexpr5exprD" "exprAexprBexprC" "exprB" "exprC" "expr5exprD"
     .5      D      
[1,] "expr5" "exprD"