replace() # string replace(string input, string pattern, string replacement [, string modifiers = ""])
The function returns a string that is obtained by replacing each non-overlapping substring
of the input that matches the given regular expression pattern with an occurrence of the replacement string,
respecting the optional modifiers. Supported modifiers are i (caseless), m (multiline), s (single line) and x (extended).
Internally, FLAT uses libpcre.
replace("flat", "^f.", "c") returns cat.replace("banAna", "na", "l", "i") uses the i modifier for case-insensitive matching and returns ball.The replacement parameter may use the captured sub-patterns from the pattern parameter
with $n or ${n}. Every such $n will be replaced with the text that has been captured
by the n’th parenthesized sub-pattern or the empty string if less than n sub-expression were
present in the pattern:
replace("foo-bar-baz", "b(.)(.)", "b$1$1$1${7}$2$2$2") returns “foo-baaarrr-baaazzz”.