Attach a standardized error message to a regex
argument. By default, the
message will be "must match the regex pattern {regex}". If the input
regex
has a negate
attribute set to TRUE
, the message will instead be
"must not match...". This message can be used with stabilize_chr()
and
stabilize_chr_scalar()
.
Value
The regex
value with names()
equal to the generated error
message.
Examples
regex_must_match("[aeiou]")
#> must match the regex pattern {.val [aeiou]}
#> "[aeiou]"
# With negation:
regex <- "[aeiou]"
attr(regex, "negate") <- TRUE
regex_must_match(regex)
#> must not match the regex pattern {.val [aeiou]}
#> "[aeiou]"
#> attr(,"negate")
#> [1] TRUE