Greedy and lazy regex: match delimiters deliberately

See how far a greedy match goes

A greedy quantifier first tries to consume as much as possible while allowing the remaining pattern to match.

With two bracketed values, a dot-star pattern can consume both as one match. Check the complete match rather than only whether it exists.

'[one][two]'.match(/\[.*\]/g) → ['[one][two]']

Make the quantifier lazy

Adding a question mark makes the quantifier prefer fewer characters. It still expands if the rest of the pattern cannot match.

For a simple flat bracket format, the lazy version finds each pair separately in this fixture.

'[one][two]'.match(/\[.*?\]/g) → ['[one]','[two]']

Express forbidden delimiters directly

A negated character class can state that content must not contain the closing delimiter. This often describes the flat grammar more clearly.

If line breaks are disallowed, exclude them explicitly too; dot behavior and character-class behavior are different.

/\[[^\]\r\n]*\]/g

Know where the flat grammar ends

Escaped delimiters and nested brackets need additional rules. A lazy quantifier does not understand nesting or quoted strings.

Use the format's parser for structured languages. Test an unmatched opener, an empty pair and a forbidden newline before deploying a flat matcher.