positive lookahead

English

Etymology

From positive +‎ lookahead.

Noun

positive lookahead (countable and uncountable, plural positive lookaheads)

1. (regular expressions) The analysis of the subsequent characters presence before the regular expression is matched (symbol: ?=).
   • 2012 August, Jan Goyvaerts, Steven Levithan, Regular Expressions Cookbook:

     Negative lookahead works just like positive lookahead, except that whereas positive lookahead matches when the regex inside the lookahead matches, negative lookahead matches when the regex inside the lookahead failed to match.

Hypernyms

• lookaround
  • lookahead