Regex ignore nested matched

Question

I am trying to parse nested data types.

Examples:

ARRAY<STRING>, MAP<STRING, INTEGER>.

When I have an array, I use that regex ^ARRAY<(.*)>$. Regex returns one group with a data type.

When I have a map, I use that regex ^MAP<(.*),(.*)>$. Regex returns two groups - first key data type and second value data type.

But it does not work when I have Map as a key/value in another Map.

Examples:

MAP<MAP<STRING, STRING>, STRING> The result should be MAP<STRING, STRING> and STRING

ARRAY<MAP<ARRAY<STRING>, MAP<STRING, INTEGER>>> The result should be MAP<ARRAY<STRING>, MAP<STRING, INTEGER>>

Is it possible to ignore nested matches? If yes - how?

Regular expressions are not really good at dealing with nested brackets like this. — Barmar, Aug 01 '22 at 15:54

score 1 · Accepted Answer · answered Aug 02 '22 at 22:32

Depending on the variant of regex, you can create a sort of pseudo parser using named subroutines. For example, this one works with PHP's PCRE variant:

/
(?(DEFINE)
   (?<TYPE> STRING | INTEGER | MAP<(?&TYPE),(?&TYPE)> | ARRAY<(?&TYPE)>))
^(?&TYPE)$
/x

The syntax varies based on the language, so you'd need to look it up.

Regex ignore nested matched

1 Answers1