langref.org - erlang and fantom - Regex

Replace the first regex match in a string with a static string

Transform "Red Green Blue" into "R*d Green Blue" by replacing /e/ with "*"

erlang

{ok, Replaced, _} = regexp:sub("Red Green Blue", "e", "*"),

re:replace("Red Green Blue", "e", "*", [{return, list}]).

fantom

replaced := Regex<|e|>.split("Red Green Blue",2).join("*")

Replace all regex matches in a string with a static string

Transform "She sells sea shells" into "She X X shells" by replacing /se\w+/ with "X"

erlang

% Erlang uses 'egrep'-compatible regular expressions, so shortcuts like '\w' not supported
{ok, Replaced, _} = regexp:gsub("She sells sea shells", "se[A-Za-z0-9_]+", "X"),

re:replace("She sells sea shells", "se\\w+", "X", [global, {return, list}]).

fantom

replaced := Regex<|se\w+|>.split("She sells sea shells").join("X")

Replace all regex matches in a string with a dynamic string

Transform "The {Quick} Brown {Fox}" into "The kciuQ Brown xoF" by reversing words in braces using the regex /\{(\w+)\}/.

erlang

% Erlang regular expressions lack both group capture and backreferences, thus this problem is not directly
% solvable. Presented solution is close, but not on-spec

String = "The {Quick} Brown {Fox}",
{match, FieldList} = regexp:matches(String, "\{([A-Za-z0-9_]+)\}"),

NewString = lists:foldl(fun ({Start, Length}, S) -> replstr(S, lists:reverse(string:substr(S, Start, Length)), Start) end, String, FieldList),

fantom

s := "The {Quick} Brown {Fox}"
m := Regex<|\{(\w+)\}|>.matcher(s)
buf := StrBuf(s.size)
last := 0
while (m.find)
{
buf.add(s[last..m.start-1]).add(m.group(1).reverse)
last = m.end
}
buf.add(s[last..-1])
replaced := buf.toStr