lookahead
- noun
- /ˈlʊkəˌhɛd/
- Specialized
:
lookahead
- The regex engine uses a lookahead assertion to check for a digit immediately after the current character without consuming it.
Examples
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To ensure a string contains a vowel, you can use a lookahead to verify that at least one vowel follows the current character.
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The second stage is the carry-propagate-add stage, which performs a 161-bit one's complement add using a carry-lookahead adder.
Academic text (1996) -
Since carry-lookahead incrementers are smaller and faster than carry-lookahead adders, the actual CLA is only 88 bits wide.
Academic text (1996) -
Since carry-lookahead incrementers are smaller and faster than carry-lookahead adders, the actual CLA is only 88 bits wide.
Academic text (1996) -
The propagation from the carry-lookahead incrementer and the group identifier generated by the 87-bit CLA are fed back to the carry-in to correct the end-around-carry problem without a closed loop.
Academic text (1996) -
In regular expressions, a lookahead allows you to assert that a specific sequence of characters follows the current position without including them in the match.
Surface Forms
Morphology
Etymology
Lookahead comes from the words look and ahead, meaning 'look forward'. In regular expressions a lookahead is like a quick look at the characters ahead without taking them into the match, which is why the name fits.
