S.I/Lisp/

TEXTBETWEEN

=TEXTBETWEEN("(123) 456 - 7890", "(", ")")
-> "123"

=TEXTBETWEEN("123-45-6789", "(", ")")
-> 123
        

DEFINE(
    TEXTBETWEEN,
    LAMBDA(
        source_text,
        first_boundary,
        second_boundary,
        LET(
            text_after_first_boundary,
                RIGHT(
                    source_text,
                    DIFFERENCE(
                        LEN(source_text),
                        DECREMENT(
                            SUM(
                                FIND(
                                    first_boundary,
                                    source_text),
                                LEN(first_boundary))))),
            LEFT(
                text_after_first_boundary,
                DECREMENT(
                    FIND(
                        second_boundary,
                        text_after_first_boundary))))))
        

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