# \#expander

**URL:** https://racket.discourse.group/tag/expander/141.md

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## [How to attach an exception to a syntactic location?](https://racket.discourse.group/t/how-to-attach-an-exception-to-a-syntactic-location/3631)

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**Author:** [@ToddOBryan](https://racket.discourse.group/u/ToddOBryan)\
**Replies:** 0\
**Last updated:** [March 16, 2025, 4:50pm UTC](https://racket.discourse.group/t/how-to-attach-an-exception-to-a-syntactic-location/3631 "2025-03-16T16:50:35Z")

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Following along with Beautiful Racket, I'm trying to implement the AP Computer Science Principles pseudo-code that is used on the exam. So far, so good. Except that I'd like to have errors attach to the locations in t…

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## [Expansion and "enriching"](https://racket.discourse.group/t/expansion-and-enriching/1294)

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**Author:** [@greghendershott](https://racket.discourse.group/u/greghendershott)\
**Replies:** 1\
**Last updated:** [September 12, 2022, 6:17pm UTC](https://racket.discourse.group/t/expansion-and-enriching/1294 "2022-09-12T18:17:34Z")

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In Racket Mode I have a cache of fully expanded syntax. Some users of the cache need it to be "enriched", as done by expand (as opposed to expand-syntax). In one case I want to "warm" the cache from a compiled load hand…