Special Capture Group References

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These patterns are described using regular expression syntax. For more information, see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions
D s product
implements a version of regular expressions based off of RE2 and PCRE regular expressions.

This section contains information on how special capture group references are managed.

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source value replace transform replacement

foobar

Code Block
replace col:MyColumn with:'$$f' on:'f'

$foobar

foobar

Code Block
replace col:MyColumn with:'$2' on:`(f)(o)(o)bar`

Note that the on parameter is a

D s item

item	pattern
r	true

.

o

Positive and Negative Lookaheads

In regular expressions, you can use positive and negative lookahead capture groups to capture content that is conditionally followed or not followed by a specified capture group.

Type Example expression

Positive lookahead

Code Block
/q(?u)/

Capture the letter q only when it is followed by the letter u. Letter u is not captured.

Negative lookahead

Code Block
/q(?!u)/

Capture the letter q when it is not followed by the letter u. Letter u is not captured.

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Positive and Negative Lookaheads