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javascriptregexrubyregex-group

Regex repeated pattern

I am tryting the match the following pattern:

((1.0 4) (2.0 5) .... (10.0 8))

The tuple (X N), where X is a floating point number with optional exponent and N is an integer, can be repeated several times.

I tried on this website and I could generate a regex for a fixed number of tuples. For example for 2 tuples I would get

^\(\(([+-]?(?=\.\d|\d)(?:\d+)?(?:\.?\d*))(?:[eE]([+-]?\d+))?\s[0-9]+\)\s\(([+-]?(?=\.\d|\d)(?:\d+)?(?:\.?\d*))(?:[eE]([+-]?\d+))?\s[0-9]+\)\)$

How can I modify the pattern so that the number of tuples is arbitrary? I think I will have to use some kind of grouping, but regex is quite new for me.

Solution

  • You may use the following pattern:

    ^\(\(\d+(?:\.\d+)? \d+\)(?:\s*\(\d+(?:\.\d+)? \d+\))*\)$

    Demo

    This pattern matches:

    ^
\(                             (
\(\d+(?:\.\d+)? \d+\)          a leading tuple
(?:\s*\(\d+(?:\.\d+)? \d+\))*  space, more tuples
\)                             )
$